International Journal of Cancer

About the journal

Publisher: Wiley-Liss
Published: 1966 to the present, United States
Language: English
ISSN: 0020-7136 (print), 1097-0215 (electronic)
Continues: Acta - Unio Internationalis Contra Cancrum
Absorbed: Radiation Oncology Investigations
Its record in the NLM Catalog

2020s

Efficacy and immunogenic effects of Tumor Treating Fields (TTFields) in preclinical models of pancreatic ductal adenocarcinoma, with and without gemcitabine/nab-paclitaxel. T. Kan, T. Haj Khalil, Y. Barsheshet, et al. 2026;158(12):3091-3100. PubMed · Publisher · Free full text

Abstract

Tumor Treating Fields (TTFields) are an approved cancer therapy for glioblastoma (GBM), pleural mesothelioma, and non-small cell lung cancer (NSCLC). A recent phase 3 trial of TTFields therapy concomitant with standard-of-care gemcitabine and nab-paclitaxel (Gem/NabP) as a first-line treatment for unresectable, locally advanced pancreatic adenocarcinoma demonstrated a significant increase in overall survival. The current study evaluated the effects of TTFields in preclinical pancreatic ductal adenocarcinoma (PDAC) models. The vast majority of PDAC patients harbor KRAS mutations, which are associated with a more aggressive disease phenotype and increased therapy resistance, driven in part by overexpression of the key transcription factor c-Myc. In the current study, TTFields application significantly suppressed c-Myc expression and induced immunogenic cell death (ICD)-characterized by increased calreticulin cell-surface exposure, extracellular ATP secretion, and elevated HMGB1 release-in pancreatic cancer models. These effects were further enhanced when TTFields were applied concomitantly with Gem/NabP. Causality between c-Myc modulation and immune readouts was not established. In vivo, TTFields application induced a systemic immune response, evidenced by dendritic cell activation, increased effector memory T cells, and greater tumor leukocyte infiltration. TTFields concomitant with Gem/NabP significantly reduced tumor volume, decreased tumor monocytic myeloid-derived suppressor cells (M-MDSC), and increased the tumor lymphocyte-to-monocyte ratio (LMR) compared to all other treatment groups. These findings support the potential of TTFields to enhance therapeutic efficacy. Moreover, TTFields-induced tumor immunogenicity may enable combination strategies with immunotherapies. A phase 2 clinical trial investigating TTFields with Gem/NabP and immune checkpoint inhibitors (ICIs) for metastatic PDAC is currently underway.

© 2026 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
Integrating polygenic and methylation risk scores for pleural mesothelioma risk stratification. K.S. Hafeez, C. Debernardi, A. Allione, et al. 2026;158(11):2866-2879. PubMed · Publisher · Free full text

Abstract

Pleural mesothelioma (PM) is a lethal cancer primarily caused by asbestos exposure. Not all exposed individuals develop PM, suggesting the involvement of additional factors. This underscores the need for robust predictive models integrating biomarkers from multi-omic domains to improve risk stratification and early detection. We developed and evaluated polygenic risk scores (PRS) and methylation risk scores (MRS) using a retrospective case-control study (749 participants: 387 PM cases, 362 controls) and a nested case-control European Prospective Investigation into Cancer and Nutrition (EPIC)-Meso study (268 participants: 134 preclinical PM cases, 134 matched controls) within the EPIC cohort. Genome-wide association analyses in the retrospective case-control study identified PM-associated variants. The PRS (1123 SNPs with p < 0.001) in the retrospective training subset stratified disease risk in the test set (ORs 3.46-9.54 across top percentiles) and improved model discrimination (AUC = 0.75 vs. 0.71 in baseline model, p = 0.04). In EPIC-Meso, PRS performance was limited (AUC = 0.52). External validation in the UK-Biobank (UKBB) confirmed a modest but consistent association with PM-risk. A Meta-PRS derived from the UKBB-FinnGen meta-analysis replicated this trend in the full retrospective dataset, showing higher OR across top percentiles (2.5-12.3) and improved discrimination (AUC 0.74 vs. 0.72, p = 0.016). MRS, with 68 differentially methylated CpGs (effect-size >|0.10|, FDR p < 0.05) in the retrospective training set, increased the AUC from 0.66 to 0.85 (p < 0.001) in the test set and from 0.51 to 0.62 in EPIC-Meso. PRS was most predictive in low-exposure groups, while MRS remained robust across exposure levels. Combined PRS-MRS models improved discrimination. Integrating multi-omic biomarkers can enhance PM-risk stratification and support earlier, targeted interventions in high-risk asbestos-exposed groups.

© 2025 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
Occupational asbestos exposure and risk of esophageal cancer: A systematic review and meta-analysis. M.S. Seyyedsalehi, P. Boffetta. 2024;154(11):1920-1929. Meta-analysis · Systematic review PubMed · Publisher

Abstract

Esophageal cancer (EC), which includes squamous cell carcinoma (ESCC) and adenocarcinoma (EAC), is an important cancer with poor prognosis and high mortality rate. Several occupational exposures have been associated with EC. We aim to investigate the association between occupational asbestos exposure and EC risk, considering types of asbestos and histology of the disease. We included studies mentioned in the list of references in previous reviews and pooled analyses, and we conducted an independent search in PubMed and Scopus. Forest plots of relative risks (RR) were constructed based on the association between occupational asbestos and EC risk. Random-effects models were used to address heterogeneity between 48 independent cohort and case-control studies. We found an association between occupational asbestos exposure and EC (meta-relative risk [RR] = 1.20, 95% confidence interval [CI] = 1.09-1.32; I2 = 58.8%, p-heterogeneity [het] <.001). The results of stratification by job (p-het = .20) indicate an increased RR among asbestos product workers (RR = 1.39, 95% CI = 1.07-1.81), asbestos applicators (RR = 1.41, 95% CI = 1.20-1.67), and construction workers (RR = 1.12, 95% CI = 1.02-1.24). There was no heterogeneity in meta-RR according to outcome (p = .29), geographic region (p = .69), year of publication (p = .59), quality score (p = .73), asbestos type (p = .93), study design (p = .87), and gender (p = .88), control for potential confounders (p = .20), year of first employment (p = .94) and exposure level (p = .43). The stratification analysis by histology type found an increased RR for both ESCC 1.33(1.03-1.71) and EAC 1.45(1.03-2.04) (p-het = .68). We didn't find evidence of publication bias (p = .07). The results of our study suggest that occupational asbestos exposure is associated with an increased risk of EC in both histology types.

© 2024 UICC.
Blood cell DNA methylation biomarkers in preclinical malignant pleural mesothelioma: The EPIC prospective cohort. A. Allione, C. Viberti, I. Cotellessa, et al. 2023;152(4):725-737. PubMed · Publisher

Abstract

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer mainly caused by asbestos exposure. Specific and sensitive noninvasive biomarkers may facilitate and enhance screening programs for the early detection of cancer. We investigated DNA methylation (DNAm) profiles in MPM prediagnostic blood samples in a case-control study nested in the European Prospective Investigation into Cancer and nutrition (EPIC) cohort, aiming to characterise DNAm biomarkers associated with MPM. From the EPIC cohort, we included samples from 135 participants who developed MPM during 20 years of follow-up and from 135 matched, cancer-free, controls. For the discovery phase we selected EPIC participants who developed MPM within 5 years from enrolment (n = 36) with matched controls. We identified nine differentially methylated CpGs, selected by 10-fold cross-validation and correlation analyses: cg25755428 (MRI1), cg20389709 (KLF11), cg23870316, cg13862711 (LHX6), cg06417478 (HOOK2), cg00667948, cg01879420 (AMD1), cg25317025 (RPL17) and cg06205333 (RAP1A). Receiver operating characteristic (ROC) analysis showed that the model including baseline characteristics (age, sex and PC1wbc) along with the nine MPM-related CpGs has a better predictive value for MPM occurrence than the baseline model alone, maintaining some performance also at more than 5 years before diagnosis (area under the curve [AUC] < 5 years = 0.89; AUC 5-10 years = 0.80; AUC >10 years = 0.75; baseline AUC range = 0.63-0.67). DNAm changes as noninvasive biomarkers in prediagnostic blood samples of MPM cases were investigated for the first time. Their application can improve the identification of asbestos-exposed individuals at higher MPM risk to possibly adopt more intensive monitoring for early disease identification.

© 2022 UICC.
Combination of PD-1/PD-L1 checkpoint inhibition and dendritic cell therapy in mice models and in patients with mesothelioma. M. van Gulijk, B. Belderbos, D. Dumoulin, et al. 2023;152(7):1438-1443. PubMed · Publisher · Free full text

Abstract

Immunotherapy with anti-PD1/PD-L1 is effective in only a subgroup of patients with malignant pleural mesothelioma (MPM). We investigated the efficacy of a combination of anti-PD1/PD-L1 and dendritic cell (DC) therapy to optimally induce effective anti-tumor immunity in MPM in both humans and mice. Data of nine MPM patients treated with DC therapy and sequential anti-PD1 treatment were collected and analyzed for progression-free survival (PFS) and overall survival (OS). Survival and T-cell responses were monitored in AC29 mesothelioma-bearing mice treated concurrently with the combination therapy; additionally, the role of the tumor-draining lymph node (TDLN) was investigated. The combination therapy resulted in a median OS and PFS of 17.7 and 8.0 months, respectively. Grade 3 to 4 treatment-related adverse events had not been reported. Survival of the mesothelioma-bearing mice treated with the combination therapy was longer than that of untreated mice, and coincided with improved T-cell activation in peripheral blood and less T-cell exhaustion in end stage tumors. Comparable results were obtained when solely the TDLN was targeted. We concluded that this combination therapy is safe and shows promising OS and PFS. The murine data support that PD-L1 treatment may reinvigorate the T-cell responses induced by DC therapy, which may primarily be the result of TDLN targeting.

© 2022 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
A defect of amphiregulin release predicted longer survival independently of YAP expression in patients with pleural mesothelioma in the IFCT-0701 MAPS phase 3 trial. E. Maille, J. Levallet, F. Dubois, et al. 2022;150(11):1889-1904. PubMed · Publisher · Free full text

Abstract

The Hippo pathway effector YAP is dysregulated in malignant pleural mesothelioma (MPM). YAP's target genes include the secreted growth factor amphiregulin (AREG), which is overexpressed in a wide range of epithelial cancers and plays an elusive role in MPM. We assayed the expression of YAP and AREG in MPM pathology samples and that of AREG additionally in plasma samples of patients from the randomized phase 3 IFCT-0701 Mesothelioma Avastin Cisplatin Pemetrexed Study (MAPS) using immunohistochemistry and ELISA assays, respectively. MPM patients frequently presented high levels of tumor AREG (64.3%), a high cytosolic AREG expression being predictive of a better prognosis with longer median overall and progression-free survival. Surprisingly, tumor AREG cytosolic expression was not correlated with secreted plasma AREG. By investigating the AREG metabolism and function in MPM cell lines H2452, H2052, MSTO-211H and H28, in comparison with the T47D ER+ breast cancer cell line used as a positive control, we confirm that AREG is important for cell invasion, growth without anchorage, proliferation and apoptosis in mesothelioma cells. Yet, most of these MPM cell lines failed to correctly execute AREG posttranslational processing by metalloprotease ADAM17/tumor necrosis factor-alpha-converting enzyme (TACE) and extracell secretion. The favorable prognostic value of high cytosolic AREG expression in MPM patients could therefore be sustained by default AREG posttranslational processing and release. Thus, the determination of mesothelioma cell AREG content could be further investigated as a prognostic marker for MPM patients and used as a stratification factor in future clinical trials.

© 2022 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
Wnt/IL-1β/IL-8 autocrine circuitries control chemoresistance in mesothelioma initiating cells by inducing ABCB5. V. Milosevic, J. Kopecka, I.C. Salaroglio, et al. 2020;146(1):192-207. PubMed · Publisher

Abstract

Malignant pleural mesothelioma (MPM) is a tumor with high chemoresistance and poor prognosis. MPM-initiating cells (ICs) are known to be drug resistant, but it is unknown if and how stemness-related pathways determine chemoresistance. Moreover, there are no predictive markers of IC-associated chemoresistance. Aim of this work is to clarify if and by which mechanisms the chemoresistant phenotype of MPM IC was due to specific stemness-related pathways. We generated MPM IC from primary MPM samples and compared the gene expression and chemo-sensitivity profile of IC and differentiated/adherent cells (AC) of the same patient. Compared to AC, IC had upregulated the drug efflux transporter ABCB5 that determined resistance to cisplatin and pemetrexed. ABCB5-knocked-out (KO) IC clones were resensitized to the drugs in vitro and in patient-derived xenografts. ABCB5 was transcriptionally activated by the Wnt/GSK3β/β-catenin/c-myc axis that also increased IL-8 and IL-1β production. IL-8 and IL-1β-KO IC clones reduced the c-myc-driven transcription of ABCB5 and reacquired chemosensitivity. ABCB5-KO clones had lower IL-8 and IL-1β secretion, and c-myc transcriptional activity, suggesting that either Wnt/GSK3β/β-catenin and IL-8/IL-1β signaling drive c-myc-mediated transcription of ABCB5. ABCB5 correlated with lower time-to-progression and overall survival in MPM patients treated with cisplatin and pemetrexed. Our work identified multiple autocrine loops linking stemness pathways and resistance to cisplatin and pemetrexed in MPM IC. ABCB5 may represent a new target to chemosensitize MPM IC and a potential biomarker to predict the response to the first-line chemotherapy in MPM patients.

© 2019 UICC.

2010s

Multigene panel sequencing of established and candidate melanoma susceptibility genes in a large cohort of Dutch non-CDKN2A/CDK4 melanoma families. T.P. Potjer, S. Bollen, A.J.E.M. Grimbergen, et al. 2019;144(10):2453-2464. PubMed · Publisher · Free full text

Abstract

Germline mutations in the major melanoma susceptibility gene CDKN2A explain genetic predisposition in only 10-40% of melanoma-prone families. In our study we comprehensively characterized 488 melanoma cases from 451 non-CDKN2A/CDK4 families for mutations in 30 established and candidate melanoma susceptibility genes using a custom-designed targeted gene panel approach. We identified (likely) pathogenic variants in established melanoma susceptibility genes in 18 families (n = 3 BAP1, n = 15 MITF p.E318K; diagnostic yield 4.0%). Among the three identified BAP1-families, there were no reported diagnoses of uveal melanoma or malignant mesothelioma. We additionally identified two potentially deleterious missense variants in the telomere maintenance genes ACD and TERF2IP, but none in the POT1 gene. MC1R risk variants were strongly enriched in our familial melanoma cohort compared to healthy controls (R variants: OR 3.67, 95% CI 2.88-4.68, p <0.001). Several variants of interest were also identified in candidate melanoma susceptibility genes, in particular rare (pathogenic) variants in the albinism gene OCA2 were repeatedly found. We conclude that multigene panel testing for familial melanoma is appropriate considering the additional 4% diagnostic yield in non-CDKN2A/CDK4 families. Our study shows that BAP1 and MITF are important genes to be included in such a diagnostic test.

© 2018 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
Presence of innate lymphoid cells in pleural effusions of primary and metastatic tumors: Functional analysis and expression of PD-1 receptor. N. Tumino, S. Martini, E. Munari, et al. 2019;145(6):1660-1668. PubMed · Publisher · Free full text

Abstract

The tumor microenvironment (TM) contains a wide variety of cell types and soluble factors capable of suppressing immune responses. While the presence of NK cells in pleural effusions (PE) has been documented, no information exists on the presence of other innate lymphoid cell (ILC) subsets and on the expression of programmed cell death-1 (PD-1) in NK and ILC. The presence of ILC was assessed in PE of 54 patients (n = 33 with mesothelioma, n = 15 with adenocarcinoma and n = 6 with inflammatory pleural diseases) by cell staining with suitable antibody combinations and cytofluorimetric analysis. The cytokine production of ILC isolated from both PE and autologous peripheral blood was analyzed upon cell stimulation and intracytoplasmic staining. We show that, in addition to NK cells, also ILC1, ILC2 and ILC3 are present in malignant PE and that the prevalent subset is ILC3. PE-ILC subsets produced their typical sets of cytokines upon activation. In addition, we analyzed the PD-1 expression on NK/ILC by multiparametric flow-cytometric analysis, while the expression of PD-1 ligand (PD-L1) was evaluated by immunohistochemical analysis. Both NK cells and ILC3 expressed functional PD-1, moreover, both tumor samples and malignant PE-derived tumor cell lines were PD-L1+ suggesting that the interaction between PD-1+ ILC and PD-L1+ tumor cells may hamper antitumor immune responses mediated by NK and ILC.

© 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
Hand-spinning chrysotile exposure and risk of malignant mesothelioma: A case-control study in Southeastern China. Z. Jiang, T. Chen, J. Chen, et al. 2018;142(3):514-523. PubMed · Publisher

Abstract

While chrysotile has been commonly used by Chinese textile industry for many years, investigations on the association of chrysotile exposure with risk of mesothelioma in China are scarce. We conducted a case-control study in a county located at Southeastern China, including 46 cases and 230 individually matched controls. A semi-quantitative method based on experts' assessment was used for evaluating hand-spinning chrysotile exposure. Conditional logistic regression models were used to assess the association of asbestos exposure with risk of mesothelioma. We found that hand-spinning chrysotile exposure was associated with significantly elevated risk of mesothelioma, reaching OR =10 (95% CIs: 1.4-65) for possible exposure and 64 (12-328) for definite exposure. Our data suggested a dose-response relationship of chrysotile exposure duration with risk of mesothelioma, reaching 28 (6-134) for <6 years, 51 (11-247) for 7-17 years and 56 (9-351) for ≥18 years. A dose-response relationship of cumulative exposure index (CEI) with risk of mesothelioma was found, reaching 28 (6-137) for CEI at 0-0.5 fibers per milliliter years (f/mL-year), 36 (7-184) for CEI at 0.5-28.6 f/mL-years and 79 (14-451) for CEI > 28.6 f/mL-years. We found a dose-response relationship of chrysotile exposure duration and CEI with risk of mesothelioma in Southeastern China, adding valuable information on health hazards of chrysotile exposure in China where chrysotile is still used nationwide.

© 2017 UICC.
Asbestos-associated genome-wide DNA methylation changes in lung cancer. E. Kettunen, H. Hernandez-Vargas, M.P. Cros, et al. 2017;141(10):2014-2029. PubMed · Publisher

Abstract

Previous studies have revealed a robust association between exposure to asbestos and human lung cancer. Accumulating evidence has highlighted the role of epigenome deregulation in the mechanism of carcinogen-induced malignancies. We examined the impact of asbestos on DNA methylation. Our genome-wide studies (using Illumina HumanMethylation450K BeadChip) of lung cancer tissue and paired normal lung from 28 asbestos-exposed or non-exposed patients, mostly smokers, revealed distinctive DNA methylation changes. We identified a number of differentially methylated regions (DMR) and differentially variable, differentially methylated CpGs (DVMC), with individual CpGs further validated by pyrosequencing in an independent series of 91 non-small cell lung cancer and paired normal lung. We discovered and validated BEND4, ZSCAN31 and GPR135 as significantly hypermethylated in lung cancer. DMRs in genes such as RARB (FDR 1.1 × 10-19 , mean change in beta [Δ] -0.09), GPR135 (FDR 1.87 × 10-8 , mean Δ -0.09) and TPO (FDR 8.58 × 10-5 , mean Δ -0.11), and DVMCs in NPTN, NRG2, GLT25D2 and TRPC3 (all with p <0.05, t-test) were significantly associated with asbestos exposure status in exposed versus non-exposed lung tumors. Hypomethylation was characteristic to DVMCs in lung cancer tissue from asbestos-exposed subjects. When DVMCs related to asbestos or smoking were analyzed, 96% of the elements were unique to either of the exposures, consistent with the concept that the methylation changes in tumors may be specific for risk factors. In conclusion, we identified novel DNA methylation changes associated with lung tumors and asbestos exposure, suggesting that changes may be present in causal pathway from asbestos exposure to lung cancer.

© 2017 UICC.
Synergistic anti-tumor efficacy of immunogenic adenovirus ONCOS-102 (Ad5/3-D24-GM-CSF) and standard of care chemotherapy in preclinical mesothelioma model. L. Kuryk, E. Haavisto, M. Garofalo, et al. 2016;139(8):1883-93. PubMed · Publisher

Abstract

Malignant mesothelioma (MM) is a rare cancer type caused mainly by asbestos exposure. The median overall survival time of a mesothelioma cancer patient is less than 1-year from diagnosis. Currently there are no curative treatment modalities for malignant mesothelioma, however treatments such as surgery, chemotherapy and radiotherapy can help to improve patient prognosis and increase life expectancy. Pemetrexed-Cisplatin is the only standard of care (SoC) chemotherapy for malignant mesothelioma, but the median PFS/OS (progression-free survival/overall survival) from the initiation of treatment is only up to 12 months. Therefore, new treatment strategies against malignant mesothelioma are in high demand. ONCOS-102 is a dual targeting, chimeric oncolytic adenovirus, coding for human GM-CSF. The safety and immune activating properties of ONCOS-102 have already been assessed in phase 1 study (NCT01598129). In this preclinical study, we evaluated the antineoplastic activity of combination treatment with SoC chemotherapy (Pemetrexed, Cisplatin, Carboplatin) and ONCOS-102 in xenograft BALB/c model of human malignant mesothelioma. We demonstrated that ONCOS-102 is able to induce immunogenic cell death of human mesothelioma cell lines in vitro and showed anti-tumor activity in the treatment of refractory H226 malignant pleural mesothelioma (MPM) xenograft model. While chemotherapy alone showed no anti-tumor activity in the mesothelioma mouse model, ONCOS-102 was able to slow down tumor growth. Interestingly, a synergistic anti-tumor effect was seen when ONCOS-102 was combined with chemotherapy regimens. These findings give a rationale for the clinical testing of ONCOS-102 in combination with first-line chemotherapy in patients suffering from malignant mesothelioma.

© 2016 UICC.
Inhibition of mesothelioma cancer stem-like cells with adenovirus-mediated NK4 gene therapy. X.B. Deng, L. Xiao, Y. Wu, et al. 2015;137(2):481-90. PubMed · Publisher · Free full text

Abstract

Malignant mesothelioma (MM) is a highly invasive and chemoresistant malignancy induced by asbestos fibers. NK4, a hepatocyte growth factor antagonist and angiogenesis inhibitor, consists of the N-terminal hairpin domain and four kringle domains of the α-chain of hepatocyte growth factor. The therapeutic potential of NK4 has been demonstrated in a variety of tumor types. However, the mechanisms by which NK4 inhibits tumor growth have not been well delineated. In this study, it is shown that the NK4 adenovirus (Ad-NK4) potently inhibits cell viability, invasiveness and tumorigenicity of human MM cells. Significantly, this study demonstrates for the first time that Ad-NK4 inhibits cancer stem-like cell (CSC) properties as assessed by spheroid formation assay, side population analysis and flow cytometric sorting of CD24 cells. In addition to inhibiting phosphorylation of Met and AKT, Ad-NK4 markedly suppressed the active form of β-catenin, a key mediator of both Wnt and AKT pathways. It is further demonstrated that expression of NK4 suppresses β-catenin nuclear localization and transcriptional activity. Intriguingly, the expression levels of Oct4 and Myc, two critical stem cell factors and downstream targets of β-catenin, were also diminished by Ad-NK4. Furthermore, the strong antitumor effect of NK4 was found to be linked to its ability to inhibit CSCs as revealed by immunohistochemical examination of tumor specimens from a mouse xenograft model of human MM. These findings suggest that NK4 acts as a CSC inhibitor by impeding Met/AKT/β-catenin signaling and holds promise for achieving durable therapeutic responses in MM by constraining the CSC component of these aggressive tumors.

© 2014 UICC.
Lung cancer risk among bricklayers in a pooled analysis of case-control studies. D. Consonni, S. De Matteis, A.C. Pesatori, et al. 2015;136(2):360-71. PubMed · Publisher · Free full text

Abstract

Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies that analyzed lung cancer risk among these workers had several study design limitations. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case-control studies on lung cancer and the joint effects of occupational carcinogens. For men ever employed as bricklayers we estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for study center, age, lifetime smoking history and employment in occupations with exposures to known or suspected lung carcinogens. Among 15,608 cases and 18,531 controls, there were 695 cases and 469 controls who had ever worked as bricklayers (OR: 1.47; 95% CI: 1.28-1.68). In studies using population controls the OR was 1.55 (95% CI: 1.32-1.81, 540/349 cases/controls), while it was 1.24 (95% CI: 0.93-1.64, 155/120 cases/controls) in hospital-based studies. There was a clear positive trend with length of employment (p < 0.001). The relative risk was higher for squamous (OR: 1.68, 95% CI: 1.42-1.98, 309 cases) and small cell carcinomas (OR: 1.78, 95% CI: 1.44-2.20, 140 cases), than for adenocarcinoma (OR: 1.17, 95% CI: 0.95-1.43, 150 cases) (p-homogeneity: 0.0007). ORs were still elevated after additional adjustment for education and in analyses using blue collar workers as referents. This study provided robust evidence of increased lung cancer risk in bricklayers. Although non-causal explanations cannot be completely ruled out, the association is plausible in view of the potential for exposure to several carcinogens, notably crystalline silica and to a lesser extent asbestos.

© 2014 UICC.
Estimated intake of vitamin D and its interaction with vitamin A on lung cancer risk among smokers. T.Y. Cheng, G.E. Goodman, M.D. Thornquist, et al. 2014;135(9):2135-45. PubMed · Publisher · Free full text

Abstract

Data are very limited on vitamin D and lung cancer prevention in high-risk populations. The authors investigated whether estimated vitamin D intake was associated with lung cancer risk and whether effect modification by vitamin A existed among current/former heavy smokers and workers with occupational exposure to asbestos. A case-cohort study selected 749 incident lung cancers and 679 noncases from the Carotene and Retinol Efficacy Trial (CARET), 1988-2005. The active intervention was supplementation of 30 mg β-carotene + 25,000 IU retinyl palmitate/day. Baseline total intake including both diet (from food frequency questionnaire) and personal supplements (from brand names linked to the labeled potencies) was assessed. Hazard ratios (HRs) were estimated by Cox proportional hazard models. No significant association of total vitamin D intake with lung cancer was observed overall. However, total vitamin D intake ≥600 versus <200 IU/day was associated with a lower risk of non-small cell lung cancer among former smokers [HR = 0.36, 95% confidence interval (CI) = 0.13-0.96]. Total vitamin D intake ≥400 versus <400 IU/day was associated with a lower risk of total lung cancer among participants who received the CARET active intervention (HR = 0.56, 95% CI = 0.32-0.99) and among those who had total vitamin A intake ≥1,500 µg/day retinol activity equivalent (RAE; HR = 0.46, 95% CI = 0.23-0.91). The beneficial associations were attenuated among those who did not receive the CARET active intervention or who had total vitamin A intake <1,500 µg/day RAE (p-interaction = 0.02 for current smokers). Our observation suggests that vitamin A may assist vitamin D in preventing lung cancer among smokers.

© 2014 UICC.
Occupational asbestos exposure and risk of esophageal, gastric and colorectal cancer in the prospective Netherlands Cohort Study. N.S. Offermans, R. Vermeulen, A. Burdorf, et al. 2014;135(8):1970-7. PubMed · Publisher

Abstract

The evidence for an association between occupational asbestos exposure and esophageal, gastric and colorectal cancer is limited. We studied this association specifically addressing risk differences between relatively low and high exposure, risk associated with cancer subtypes, the influence of potential confounders and the interaction between asbestos and smoking in relation to cancer risk. Using the Netherlands Cohort Study (n = 58,279 men, aged 55-69 years at baseline), asbestos exposure was estimated by linkage to a job-exposure matrix. After 17.3 years of follow-up, 187 esophageal, 486 gastric and 1,724 colorectal cancer cases were available for analysis. The models adjusted for age and family history of cancer showed that mainly (prolonged) exposure to high levels of asbestos was statistically significantly associated with risk of esophageal adenocarcinoma (EAC), total and distal colon cancer and rectal cancer. For overall gastric cancer and gastric non-cardia adenocarcinoma (GNCA), also exposure to lower levels of asbestos was associated. Additional adjustment for lifestyle confounders, especially smoking status, yielded non-significant associations with overall gastric cancer and GNCA in the multivariable-adjusted model, except for the prolonged highly exposed subjects (tertile 3 vs. never: HR 2.67, 95% CI: 1.11-6.44 and HR 3.35, 95% CI: 1.33-8.44, respectively). No statistically significant additive or multiplicative interaction between asbestos and smoking was observed for any of the studied cancers. This prospective population-based study showed that (prolonged) high asbestos exposure was associated with overall gastric cancer, EAC, GNCA, total and distal colon cancer and rectal cancer.

© 2014 UICC.
Calretinin is essential for mesothelioma cell growth/survival in vitro: a potential new target for malignant mesothelioma therapy?. W. Blum, B. Schwaller. 2013;133(9):2077-88. PubMed · Publisher

Abstract

Malignant mesothelioma (MM) are highly aggressive asbestos-related neoplasms, which show strong chemotherapy resistance, and there is no effective cure for MM so far. Calretinin (CR) is widely used as a diagnostic marker for epithelioid and mixed (biphasic) mesothelioma; however, little is known about CR's putative functions in tumorigenesis. CR protects against asbestos-induced acute cytotoxicity mediated by the AKT/PI3K pathway, and furthermore, SV40 early region genes are able to upregulate CR in mesothelial cells. However, the precise role of CR in mesothelioma is still unknown. Downregulation of CR via lentiviral-mediated short-hairpin RNA significantly decreased the viability and proliferation of mesothelioma cells in vitro. The effect was strong in epithelioid-dominated cell lines (ZL55 and MSTO-211H). A weaker and delayed effect was observed in mesothelioma cells with prevalent sarcomatoid morphology (SPC111, SPC212 and ZL34). The specificity of the effect was confirmed by stable enhanced green fluorescent protein-CR expression in mesothelioma cell lines and subsequent downregulation. Depletion of CR led these cancer cell lines to enter apoptosis within 72 hr postinfection via strong activation of the intrinsic caspase 9-dependent pathway. Downregulation of CR in immortalized mesothelial cells LP9/TERT-1 strongly blocked proliferation and caused a G1 block without decreasing viability or activating apoptosis pathways. These results demonstrate that downregulation of CR had a strong effect on the viability of MM cells and that CR is essential for cells derived from MM. The authors anticipate these findings to reveal CR as a highly interesting new putative therapeutic target for mesothelioma treatment of especially the epithelioid, as well as of the mixed and sarcomatoid type.

© 2013 UICC.
Familial aggregation of malignant mesothelioma in former workers and residents of Wittenoom, Western Australia. N. de Klerk, H. Alfonso, N. Olsen, et al. 2013;132(6):1423-8. PubMed · Publisher

Abstract

Clustering of cases of malignant mesothelioma within families has often been observed, but disentangling genetic and exposure effects has not been done. Former workers and residents exposed to crocidolite at Wittenoom, Western Australia, where many families shared exposure to asbestos, have had high rates of mesothelioma. Our study aimed to estimate the additional risk of mesothelioma in relatives, after allowance for common exposure to crocidolite. More than 11,000 former asbestos workers and residents from Wittenoom have been followed up in cancer and death registries. Levels of exposure for all members of the Wittenoom cohorts have been estimated previously. Relationships between family members of all mesothelioma cases were established from questionnaires, birth and death certificates. Expected numbers of cases of mesothelioma were estimated by fitting a Weibull survival model to all data, based on time from first asbestos exposure, duration and intensity of exposure and age. For each family group, the earliest case was considered the index case. Predicted risk was estimated for each subject from the time of diagnosis of the index case. Familial risk ratios were estimated by dividing observed cases by the sum of risks of all same degree relatives of index cases. There were 369 family groups with at least one case of mesothelioma and a further 25 cases of mesothelioma among relatives in the same families, with 12.9 expected. The risk ratio for blood relatives was 1.9 (95% confidence interval [CI] = 1.3-2.9, p = 0.002). These findings suggest an important, but not large, genetic component in mesothelioma, similar to many other cancers.

Copyright © 2012 UICC.
Fowlpox-based survivin vaccination for malignant mesothelioma therapy. P. Bertino, M. Panigada, E. Soprana, et al. 2013;133(3):612-23. PubMed · Publisher · Free full text

Abstract

Survivin protein is an attractive candidate for cancer immunotherapy since it is abundantly expressed in most common human cancers and mostly absent in normal adult tissues. Malignant mesothelioma (MM) is a deadly cancer associated with asbestos or erionite exposure for which no successful therapies are currently available. In this study, we evaluated the therapeutic efficacy of a novel survivin-based vaccine by subcutaneous or intraperitoneum injection of BALB/c mice with murine fiber-induced MM tumor cells followed by vaccination with recombinant Fowlpox virus replicons encoding survivin. Vaccination generated significant immune responses in both models, leading to delayed tumor growth and improved animal survival. Flow cytometry and immunofluorescence analyses of tumors from vaccinated mice showed CD8(+) T-cell infiltration, and real-time PCR demonstrated increased mRNA and protein levels of immunostimulatory cytokines. Analyses of survivin peptide-pulsed spleen and lymph node cells from vaccinated mice using ELISPOT and intracellular cytokine staining confirmed antigen-specific, interferon-γ-producing CD8(+) T-cell responses. In addition pentamer-based flow cytometry showed that vaccination generated survivin-specific CD8(+) T cells. Importantly, vaccination did not affect fertility or induce autoimmune abnormalities in mice. Our results demonstrate that vaccination with recombinant Fowlpox expressing survivin improves T-cell responses against aggressive MM tumors and may form the basis for promising clinical applications.

Copyright © 2013 UICC.
Efficacy of anti-insulin-like growth factor I receptor monoclonal antibody cixutumumab in mesothelioma is highly correlated with insulin growth factor-I receptor sites/cell. N. Kalra, J. Zhang, Y. Yu, et al. 2012;131(9):2143-52. PubMed · Publisher · Free full text

Abstract

Insulin growth factor-I receptor (IGF-IR) is expressed in mesothelioma and therefore an attractive target for therapy. The antitumor activity of cixutumumab, a humanized monoclonal antibody to IGF-IR, in mesothelioma and relationship to IGF-IR expression was investigated using eight early passage tumor cells obtained from patients, nine established cell lines and an in vivo human mesothelioma tumor xenograft model. Although IGF-IR expression at the mRNA and protein level was present in all mesothelioma cells, using a quantitative ELISA immunoassay, there was considerable variability of IGF-IR expression ranging from 1 to 14 ng/mg of lysate. Using flow cytometry, the number of IGF-IR surface receptors varied from ≈ 2,000 to 50,000 sites/cell. Cells expressing >10,000 sites/cell had greater than 10% growth inhibition when treated with cixutumumab (100 μg/ml). Cixutumumab also induced antibody-dependent cell-mediated toxicity (>10% specific lysis) in cell lines, which had >20,000 IGF-IR sites/cell. Treatment with cixutumumab decreased phosphorylation of IGF-IR, Akt and Erk in cell lines, H226 and H28 having 24,000 and 51,000 IGF-IR sites/cell, respectively, but not in the cell line H2052 with 3,000 IGF-IR sites/cell. In vivo, cixutumumab treatment delayed growth of H226 mesothelioma tumor xenografts in mice and improved the overall survival of these mice compared to mice treated with saline (p < 0.004). Our results demonstrate that the antitumor efficacy of cixutumumab including inhibition of IGF-IR downstream signaling is highly correlated with IGF-IR sites/cell. A phase II clinical trial of cixutumumab is currently ongoing for the treatment of patients with mesothelioma.

Copyright © 2012 UICC.
Pleural malignant mesothelioma epidemic: incidence, modalities of asbestos exposure and occupations involved from the Italian National Register. A. Marinaccio, A. Binazzi, D.D. Marzio, et al. 2012;130(9):2146-54. PubMed · Publisher

Abstract

Due to the large scale use of asbestos (more than 3.5 million tons produced or imported until its definitive banning in 1992), a specific national surveillance system of mesothelioma incident cases is active in Italy, with direct and individual anamnestic etiological investigation. In the period between 1993 and 2004, a case-list of 8,868 pleural MM was recorded by the Italian National Register (ReNaM) and the modalities of exposure to asbestos fibres have been investigated for 6,603 of them. Standardized incidence rates are 3.49 (per 100,000 inhabitants) for men and 1.25 for women, with a wide regional variability. Occupational asbestos exposure was in 69.3% of interviewed subjects (N = 4,577 cases), while 4.4% was due to cohabitation with someone (generally, the husband) occupationally exposed, 4.7% by environmental exposure from living near a contamination source and 1.6% during a leisure activity. In the male group, 81.5% of interviewed subjects exhibit an occupational exposure. In the exposed workers, the median year of first exposure was 1957, and mean latency was 43.7 years. The analysis of exposures by industrial sector focuses on a decreasing trend for those traditionally signaled as "at risk" (asbestos-cement industry, shipbuilding and repair and railway carriages maintenance) and an increasing trend for the building construction sector. The systematic mesothelioma surveillance system is relevant for the prevention of the disease and for supporting an efficient compensation system. The existing experience on all-too-predictable asbestos effects should be transferred to developing countries where asbestos use is spreading.

Copyright © 2011 UICC.
The circadian clock gene BMAL1 is a novel therapeutic target for malignant pleural mesothelioma. M. Elshazley, M. Sato, T. Hase, et al. 2012;131(12):2820-31. PubMed · Publisher · Free full text

Abstract

Malignant pleural mesothelioma (MPM) is a highly aggressive neoplasm arising from the mesothelial cells lining the parietal pleura and it exhibits poor prognosis. Although there has been significant progress in MPM treatment, development of more efficient therapeutic approaches is needed. BMAL1 is a core component of the circadian clock machinery and its constitutive overexpression in MPM has been reported. Here, we demonstrate that BMAL1 may serve as a molecular target for MPM. The majority of MPM cell lines and a subset of MPM clinical specimens expressed higher levels of BMAL1 compared to a nontumorigenic mesothelial cell line (MeT-5A) and normal parietal pleural specimens, respectively. A serum shock induced a rhythmical BMAL1 expression change in MeT-5A but not in ACC-MESO-1, suggesting that the circadian rhythm pathway is deregulated in MPM cells. BMAL1 knockdown suppressed proliferation and anchorage-dependent and independent clonal growth in two MPM cell lines (ACC-MESO-1 and H290) but not in MeT-5A. Notably, BMAL1 depletion resulted in cell cycle disruption with a substantial increase in apoptotic and polyploidy cell population in association with downregulation of Wee1, cyclin B and p21(WAF1/CIP1) and upregulation of cyclin E expression. BMAL1 knockdown induced mitotic catastrophe as denoted by disruption of cell cycle regulators and induction of drastic morphological changes including micronucleation and multiple nuclei in ACC-MESO-1 cells that expressed the highest level of BMAL1. Taken together, these findings indicate that BMAL1 has a critical role in MPM and could serve as an attractive therapeutic target for MPM.

Copyright © 2012 UICC.
A novel high-affinity human monoclonal antibody to mesothelin. M. Ho, M. Feng, R.J. Fisher, et al. 2011;128(9):2020-30. PubMed · Publisher · Free full text

Abstract

Mesothelin is a glycosylphosphatidylinositol-anchored glycoprotein that is highly expressed on the cell surface of mesothelioma, ovarian cancer and other malignant tumors. The interaction between mesothelin and CA125 (also called MUC16) may facilitate the implantation and metastasis of tumors in the peritoneal cavity. A desirable therapeutic agent involves finding a fully human monoclonal antibody (mAb) that binds to mesothelin or CA125 and inhibits their interaction. Here, we report the identification of a novel human mAb to mesothelin. HN1, a human single-chain Fv specific for mesothelin, was isolated from a naïve human single-chain variable fragment (scFv) phage display library. To investigate HN1 as a potential therapeutic, we generated a fully human IgG with the γ 1 heavy chain and the κ light chain and an immuntoxin by fusing the HN1 scFv to a truncated Pseudomonas exotoxin A. The HN1 IgG kills cancer cells with very strong antibody-dependent cell-mediated cytotoxicity. HN1 binds a conformation-sensitive epitope in human mesothelin with high affinity (K(D) = 3 nM). The HN1 epitope is different from that of SS1, a mouse Fv used to develop therapeutic antibodies that are currently in clinical trials. HN1 binds to cell surface-associated mesothelin on human mesothelioma, ovarian cancer, lung adenocarcinoma and pancreatic cancer cells. In addition, HN1 can functionally block the interaction of mesothelin and CA125 on cancer cells. Most importantly, because the HN1 immuntoxin kills mesothelin-expressing cancer cells with high cytotoxic activity, we believe that it has significant potential for mesothelin-expressing cancer treatment and diagnosis.

Copyright © 2010 UICC.
ERK2 is essential for the growth of human epithelioid malignant mesotheliomas. A. Shukla, J.M. Hillegass, M.B. MacPherson, et al. 2011;129(5):1075-86. PubMed · Publisher · Free full text

Abstract

Members of the extracellular signal-regulated kinase (ERK) family may have distinct roles in the development of cell injury and repair, differentiation and carcinogenesis. Here, we show, using a synthetic small-molecule MEK1/2 inhibitor (U0126) and RNA silencing of ERK1 and 2, comparatively, that ERK2 is critical to transformation and homeostasis of human epithelioid malignant mesotheliomas (MMs), asbestos-induced tumors with a poor prognosis. Although MM cell (HMESO) lines stably transfected with shERK1 or shERK2 both exhibited significant decreases in cell proliferation in vitro, injection of shERK2 cells, and not shERK1 cells, into immunocompromised severe combined immunodeficiency (SCID) mice showed significant attenuated tumor growth in comparison to shControl (shCon) cells. Inhibition of migration, invasion and colony formation occurred in shERK2 MM cells in vitro, suggesting multiple roles of ERK2 in neoplasia. Microarray and quantitative real-time PCR analyses revealed gene expression that was significantly increased (CASP1, TRAF1 and FAS) or decreased (SEMA3E, RPS6KA2, EGF and BCL2L1) in shERK2-transfected MM cells in contrast to shCon-transfected MM cells. Most striking decreases were observed in mRNA levels of Semaphorin 3 (SEMA3E), a candidate tumor suppressor gene linked to inhibition of angiogenesis. These studies demonstrate a key role of ERK2 in novel gene expression critical to the development of epithelioid MMs. After injection of sarcomatoid human MM (PPMMill) cells into SCID mice, both shERK1 and shERK2 lines showed significant decreased tumor growth, suggesting heterogeneous effects of ERKs in individual MMs.

Copyright © 2010 UICC.
Increased efficacy of doxorubicin delivered in multifunctional microparticles for mesothelioma therapy. J.M. Hillegass, S.R. Blumen, K. Cheng, et al. 2011;129(1):233-44. PubMed · Publisher · Free full text

Abstract

New and effective treatment strategies are desperately needed for malignant mesothelioma (MM), an aggressive cancer with a poor prognosis. We have shown previously that acid-prepared mesoporous microspheres (APMS) are nontoxic after intrapleural or intraperitoneal (IP) administration to rodents. The purpose here was to evaluate the utility of APMS in delivering chemotherapeutic drugs to human MM cells in vitro and in two mouse xenograft models of MM. Uptake and release of doxorubicin (DOX) alone or loaded in APMS (APMS-DOX) were evaluated in MM cells. MM cell death and gene expression linked to DNA damage/repair were also measured in vitro. In two severe combined immunodeficient mouse xenograft models, mice received saline, APMS, DOX or APMS-DOX injected directly into subcutaneous (SC) MM tumors or injected IP after development of human MMs peritoneally. Other mice received DOX intravenously (IV) via tail vein injections. In comparison to DOX alone, APMS-DOX enhanced intracellular uptake of DOX, MM death and expression of GADD34 and TP73. In the SC MM model, 3× weekly SC injections of APMS-DOX or DOX alone significantly inhibited tumor volumes, and systemic DOX administration was lethal. In mice developing IP MMs, significant (p < 0.05) inhibition of mesenteric tumor numbers, weight and volume was achieved using IP administration of APMS-DOX at one-third the DOX concentration required after IP injections of DOX alone. These results suggest APMS are efficacious for the localized delivery of lower effective DOX concentrations in MM and represent a novel means of treating intracavitary tumors.

Copyright © 2010 UICC.
Molecular imaging of mesothelioma by detection of manganese-superoxide dismutase activity using manganese-enhanced magnetic resonance imaging. S. Hasegawa, M. Koshikawa-Yano, S. Saito, et al. 2011;128(9):2138-46. PubMed · Publisher

Abstract

Malignant mesothelioma (MM) is a fatal malignancy with a rapidly increasing incidence in industrialized countries because of the widespread use of asbestos in the past centuries. Early diagnosis of MM is critical for a better prognosis, but this is often difficult because of the lack of disease-specific diagnostic imaging. Here, we report that manganese-enhanced magnetic resonance imaging (MEMRI) represents a promising approach for a more selective mesothelioma imaging by monitoring a high-level expression of manganese-superoxide dismutase (Mn-SOD), which is observed in many MM. We found that most human MM cells overexpressed Mn-SOD protein compared with human mesothelial cells and that NCI-H226 human MM cells highly expressed Mn-SOD and augmented Mn accumulation when loaded with manganese chloride (MnCl(2)). The cells showed marked T(1)-signal enhancement on in vitro MRI after incubation with MnCl(2) because of the T(1) shortening effect of Mn(2+). H226 subcutaneous tumor was preferentially enhanced compared with a lung adenocarcinoma cell tumor and another human MM cell tumor in MnCl(2)-enhanced T(1)-weighted MR image (T(1)WI), correlating with their respective Mn-SOD expression levels. Moreover, in a more clinically relevant setting, H226 xenografted pleural tumor was markedly enhanced and readily detected by MEMRI using manganese dipyridoxyl diphosphate (MnDPDP), a clinically used contrast agent, as well as MnCl(2). Therefore, we propose that MEMRI can be a potentially powerful method for noninvasive detection of MM, with high spatial resolution and marked signal enhancement, by targeting Mn-SOD.

Copyright © 2010 UICC.
PET imaging of tumor angiogenesis in mice with VEGF-A-targeted (86)Y-CHX-A″-DTPA-bevacizumab. T.K. Nayak, K. Garmestani, K.E. Baidoo, et al. 2011;128(4):920-6. PubMed · Publisher · Free full text

Abstract

Bevacizumab is a humanized monoclonal antibody that binds to tumor-secreted vascular endothelial growth factor (VEGF)-A and inhibits tumor angiogenesis. In 2004, the antibody was approved by the US Food and Drug Administration (FDA) for the treatment of metastatic colorectal carcinoma in combination with chemotherapy. This report describes the preclinical evaluation of a radioimmunoconjugate, (86)Y-CHX-A″-DTPA-bevacizumab, for potential use in Positron Emission Tomography (PET) imaging of VEGF-A tumor angiogenesis and as a surrogate marker for (90)Y-based radioimmunotherapy. Bevacizumab was conjugated to CHX-A″-DTPA and radiolabeled with (86)Y. In vivo biodistribution and PET imaging studies were performed on mice bearing VEGF-A-secreting human colorectal (LS-174T), human ovarian (SKOV-3) and VEGF-A-negative human mesothelioma (MSTO-211H) xenografts. Biodistribution and PET imaging studies demonstrated highly specific tumor uptake of the radioimmunoconjugate. In mice bearing VEGF-A-secreting LS-174T, SKOV-3 and VEGF-A-negative MSTO-211H tumors, the tumor uptake at 3 days postinjection was 13.6 ± 1.5, 17.4 ± 1.7 and 6.8 ± 0.7 % ID/g, respectively. The corresponding tumor uptake in mice coinjected with 0.05 mg cold bevacizumab were 5.8 ± 1.3, 8.9 ± 1.9 and 7.4 ± 1.0 % ID/g, respectively at the same time point, demonstrating specific blockage of the target in VEGF-A-secreting tumors. The LS-174T and SKOV3 tumors were clearly visualized by PET imaging after injecting 1.8-2.0 MBq (86)Y-CHX-A″-DTPA-bevacizumab. Organ uptake quantified by PET closely correlated (r(2) = 0.87, p = 0.64, n = 18) to values determined by biodistribution studies. This preclinical study demonstrates the potential of the radioimmunoconjugate, (86)Y-CHX-A″-DTPA-bevacizumab, for noninvasive assessment of the VEGF-A tumor angiogenesis status and as a surrogate marker for (90)Y-CHX-A″-DTPA-bevacizumab radioimmunotherapy.

Copyright © 2010 UICC.
Beta-carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials. N. Druesne-Pecollo, P. Latino-Martel, T. Norat, et al. 2010;127(1):172-84. Meta-analysis · Systematic review PubMed · Publisher

Abstract

The effect of beta-carotene supplementation on cancer incidence has been investigated in several randomized controlled trials. The objective was to review the effect of beta-carotene supplementation on cancer incidence in randomized trials by cancer site, beta-carotene supplementation characteristics and study population. Relevant trials were retrieved by searching PubMed (up to April 2009). Authors involved in selected studies were contacted for additional information. Thirteen publications reporting results from 9 randomized controlled trials were included. Overall, no effect of beta-carotene supplementation was observed on the incidence of all cancers combined (RR, 1.01; 95% CI, 0.98-1.04), pancreatic cancer (RR, 0.99; 95% CI, 0.73-1.36), colorectal cancer (RR, 0.96; 95% CI, 0.85-1.09), prostate cancer (RR, 0.99; 95% CI, 0.91-1.07), breast cancer (RR, 0.96; 95% CI, 0.85-1.10), melanoma (RR, 0.98; 95% CI, 0.65-1.46) and non melanoma skin cancer (RR, 0.99; 95% CI, 0.93-1.05). The incidence of lung and stomach cancers were significantly increased in individuals supplemented with beta-carotene at 20-30 mg day(-1) (RR, 1.16; 95% CI, 1.06-1.27 and RR, 1.34; 95% CI, 1.06-1.70), in smokers and asbestos workers (RR, 1.20; 95% CI, 1.07-1.34 and RR, 1.54; 95% CI, 1.08-2.19) compared to the placebo group. Beta-carotene supplementation has not been shown to have any beneficial effect on cancer prevention. Conversely, it was associated with increased risk not only of lung cancer but also of gastric cancer at doses of 20-30 mg day(-1), in smokers and asbestos workers. This study adds to the evidence that nutritional prevention of cancer through beta-carotene supplementation should not be recommended.

In plain English

This was a systematic review and meta-analysis. It pooled 9 randomized controlled trials (13 publications, 182,323 participants) that compared beta-carotene supplements, given alone or with other antioxidants, against placebo for cancer incidence. Asbestos appears only as a feature of the populations studied. In two trials (ATBC and CARET), all participants were smokers or asbestos workers, and the authors analyzed these two trials together; asbestos workers were not analyzed separately. Across all trials, supplementation had no statistically significant effect on all cancers combined (RR 1.01; 95% CI 0.98–1.04). It also had no significant effect on pancreatic, colorectal, prostate, breast or skin cancers. Lung cancer risk was higher in supplemented people overall (RR 1.13; 95% CI 1.04–1.24). In the two smoker/asbestos-worker trials, supplemented participants had higher risks of lung cancer (RR 1.20; 95% CI 1.07–1.34), stomach cancer (RR 1.54; 95% CI 1.08–2.19) and all cancers (RR 1.08; 95% CI 1.01–1.15). Doses of 20 mg per day and above were also associated with more lung and stomach cancer. The authors said they could not tell whether dose or smoking/asbestos exposure mattered more. They concluded that beta-carotene supplements should not be recommended for primary cancer prevention.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.
Downregulated microRNAs in the differential diagnosis of malignant pleural mesothelioma. G.V. Gee, D.C. Koestler, B.C. Christensen, et al. 2010;127(12):2859-69. PubMed · Publisher · Free full text

Abstract

Malignant pleural mesothelioma (MPM) is a rapidly fatal disease whose diagnosis, particularly through less invasive techniques such as analysis of pleural effusion, can be challenging. Currently, a commercially available diagnostic test based on microRNA (miRNA) expression patterns is purported to distinguish between mesothelioma and lung adenocarcinoma. Yet, the biological basis of this technology has not been reported in the literature, and little research has been aimed at determining how differential miRNA expression contributes to the differences in pathogenesis between these diseases, both of which can be caused by asbestos exposure. We sought to illuminate the molecular differences between mesothelioma and lung adenocarcinoma by using miRNA microarrays to identify patterns in the most differentially expressed miRNAs. From this, we identified a panel of miRNAs, including members of the miR-200 gene family, that were all downregulated in MPM compared to lung adenocarcinoma. Using the more sensitive detection method of quantitative RT-PCR on an independent series of tumors, we validated the specificity of these alterations in 100 MPMs and 32 lung adenocarcinomas. Statistical analysis reveals that these miRNAs exceed the current recommendations for biomarkers and could greatly aid in the differential diagnosis. Further examination led us to predict that they act as redundant regulators of wnt signaling and suggests a role for this pathway in tumor progression. This research points to novel approaches using miRNAs whose decreased expression is unique to mesothelioma as potentially suitable for rapid diagnosis and reveals prospective new targets for the treatment of this deadly disease.

Copyright © 2010 UICC.
Occupational exposures contribute to educational inequalities in lung cancer incidence among men: Evidence from the EPIC prospective cohort study. G. Menvielle, H. Boshuizen, A.E. Kunst, et al. 2010;126(8):1928-1935. PubMed · Publisher · Free full text

Abstract

The aim of this study is to investigate to what extent occupational exposures may explain socioeconomic inequalities in lung cancer incidence after adjusting for smoking and dietary factors. Analyses were based on a subsample of the European Prospective Investigation into Cancer and Nutrition (EPIC study), a prospective cohort. The analyses included 703 incident lung cancer cases among men in Denmark, the United Kingdom, Germany, Italy, Spain and Greece. The socioeconomic position was measured using the highest level of education. The estimates of relative indices of inequality (RII) were computed with Cox regression models. We first adjusted for smoking (with detailed information on duration and quantity) and dietary factors (fruits and vegetables consumption) and then for occupational exposures. The exposure to three carcinogens [asbestos, heavy metals and polycyclic aromatic hydrocarbons (PAH)] was analyzed. The occupational exposures explained 14% of the socioeconomic inequalities remaining after adjustment for smoking and fruits and vegetables consumption. The inequalities remained nevertheless statistically significant. The RII decreased from 1.87 (95% CI: 1.36-2.56) to 1.75 (1.27-2.41). The decrease was more pronounced when adjusting for asbestos than for heavy metals or PAH. Analyses by birth cohort suggested an effect of occupational exposures among older men, while due to small number of endpoints, no conclusion could be drawn about the role of occupational exposures in educational inequalities among younger men. Our study revealed that the impact of occupational exposures on socioeconomic inequalities in cancer incidence, rarely studied until now, exists while of modest magnitude.

2000s

Genomic events associated with progression of pleural malignant mesothelioma. S.V. Ivanov, J. Miller, R. Lucito, et al. 2009;124(3):589-99. PubMed · Publisher · Free full text

Abstract

Pleural malignant mesothelioma (MM) is an aggressive cancer with a very long latency and a very short median survival. Little is known about the genetic events that trigger MM and their relation to poor outcome. The goal of our study was to characterize major genomic gains and losses associated with MM origin and progression and assess their clinical significance. We performed Representative Oligonucleotide Microarray Analysis (ROMA) on DNA isolated from tumors of 22 patients who recurred at variable interval with the disease after surgery. The total number of copy number alterations (CNA) and frequent imbalances for patients with short time (<12 months from surgery) and long time to recurrence were recorded and mapped using the Analysis of Copy Errors algorithm. We report a profound increase in CNA in the short-time recurrence group with most chromosomes affected, which can be explained by chromosomal instability associated with MM. Deletions in chromosomes 22q12.2, 19q13.32 and 17p13.1 appeared to be the most frequent events (55-74%) shared between MM patients followed by deletions in 1p, 9p, 9q, 4p, 3p and gains in 5p, 18q, 8q and 17q (23-55%). Deletions in 9p21.3 encompassing CDKN2A/ARF and CDKN2B were characterized as specific for the short-term recurrence group. Analysis of the minimal common areas of frequent gains and losses identified candidate genes that may be involved in different stages of MM: OSM (22q12.2), FUS1 and PL6 (3p21.3), DNAJA1 (9p21.1) and CDH2 (18q11.2-q12.3). Imbalances seen by ROMA were confirmed by Affymetrix genome analysis in a subset of samples.

Copyright (c) 2008 Wiley-Liss, Inc.
Optical detection and grading of lung neoplasia by Raman microspectroscopy. P.R. Jess, M. Mazilu, K. Dholakia, et al. 2009;124(2):376-80. PubMed · Publisher

Abstract

The aim of this study was to investigate whether Raman spectroscopy could be used to identify and potentially grade lung neoplasia in cell samples. Normal human bronchial epithelial cells (HBEpCs) were analyzed by Raman spectroscopy and compared with (i) HBEpCs expressing human papillomavirus (HPV) type 16 E7 or CDK4; (ii) the immortalized bronchial epithelial cell line BEP2D and (iii) its asbestos-transformed derivative AsbTB2A. Overall, Raman spectroscopy, in combination with a linear discriminant analysis algorithm, was able to identify abnormal cells with a sensitivity of 91% and a specificity of 75%. Subdivision of the cell types into 3 groups, representing normal cells (HBEpCs), cells with extended lifespan (HBEpCs expressing HPV 16 E7 or CDK4) and immortalized/transformed cells (BEP2D and AsbTB2A) showed that Raman spectroscopy identifies cells in these categories correctly with sensitivities of 75, 79 and 87%, and specificities of 91, 85 and 96%, respectively. In conclusion, Raman spectroscopy can, with high sensitivity, detect the presence of neoplastic development in lung cells and identify the stage of this development accurately, suggesting that this minimally invasive optical technology has potential for lung cancer diagnosis.

Copyright (c) 2008 Wiley-Liss, Inc.
Survival of pleural malignant mesothelioma in Italy: a population-based study. F. Montanaro, R. Rosato, M. Gangemi, et al. 2009;124(1):201-7. PubMed · Publisher

Abstract

A median survival time of about 9 months is generally reported among malignant pleural mesothelioma cases. Recently, better results in terms of survival and performance status have been reported in clinical trials that included highly selected patients. We describe the survival of pleural mesothelioma patients and the factors predictive of survival in an unselected, population-based setting. Pleural mesothelioma cases (4,100) registered from 1990 to 2001 by 9 Italian regional mesothelioma registries contributing to the network of the National Mesothelioma Registry were followed until December 31, 2005. Univariate (Kaplan-Meier) and multivariate (Cox proportional hazards regression) analyses of survival were carried out according to selected individual characteristics, including limited information on treatment in a subset of 578 cases. The median survival time was 9.8 months (95% confidence interval: 9.4-10.1). In multivariate analysis, younger age at diagnosis and epithelioid histotype were associated with significantly reduced hazard ratios. Positive effects of gender (women) and being diagnosed in a hospital with a thoracic surgery unit were of border-line statistical significance. No association with calendar period of diagnosis or asbestos exposure was present. Treatment was not associated with a statistically significant improvement in survival. This is the largest population-based study on survival in patients with pleural mesothelioma to date. Age and morphology were the main prognostic factors. Results regarding the effect of treatment were disappointing but may be useful to assess the future impact, at the population level, of recently introduced therapies.
Cancer incidence among women and girls environmentally and occupationally exposed to blue asbestos at Wittenoom, Western Australia. A. Reid, J. Heyworth, N.H. de Klerk, et al. 2008;122(10):2337-44. PubMed · Publisher

Abstract

The impact of crocidolite exposure on the health of former Wittenoom miners and millers (largely male) has been well documented. Less is known about the health outcomes of the 2,968 women and girls who lived (N = 2,552) and worked (N = 416) in the blue asbestos milling and mining town of Wittenoom between 1943 and 1992. Quantitative exposure measurements were derived from dust studies undertaken over the lifetime of the mine and mill and the township. Incident cancers were obtained from the Western Australian (WA) Cancer Registry and the National Cancer Clearing House. Standardized incidence ratios (SIRS) compared Wittenoom females with the WA female population. Exposure-response relationships were examined using a matched case-control study design. There were (47) mesothelioma and (55) lung cancer cases among the 437 cancers in the Wittenoom females over the period 1960-2005. When compared to the WA female population, Wittenoom women and girls had higher rates of mesothelioma and possibly lung cancer. Mesothelioma incidence rates are increasing with the incidence rate of 193 per 100,000 in the period 2000-2005 being more than double that for the period 1995-1999 at 84 per 100,000. A significant exposure-response relationship was present for mesothelioma, but not for lung cancer. Forty years after the asbestos mine and mill at Wittenoom were closed, there is a high toll from cancer among the former female residents of the town and company workers.

(c) 2008 Wiley-Liss, Inc.
Long-term mortality from pleural and peritoneal cancer after exposure to asbestos: Possible role of asbestos clearance. F. Barone-Adesi, D. Ferrante, M. Bertolotti, et al. 2008;123(4):912-6. PubMed · Publisher

Abstract

Models based on the multistage theory of carcinogenesis predict that the rate of mesothelioma increases monotonically as a function of time since first exposure (TSFE) to asbestos. Predictions of long-term mortality (TSFE >or= 40 years) are, however, still untested, because of the limited follow-up of most epidemiological studies. Some authors have suggested that the increase in mesothelioma rate with TSFE might be attenuated by clearance of asbestos from the lungs. We estimated mortality time trends from pleural and peritoneal cancer in a cohort of 3,443 asbestos-cement workers, followed for more than 50 years. The functional relation between mesothelioma rate and TSFE was evaluated with various regression models. The role of asbestos clearance was explored using the traditional mesothelioma multistage model, generalized to include a term representing elimination over time. We observed 139 deaths from pleural and 56 from peritoneal cancer during the period 1950-2003. The rate of pleural cancer increased during the first 40 years of TSFE and reached a plateau thereafter. In contrast, the rate of peritoneal cancer increased monotonically with TSFE. The model allowing for asbestos elimination fitted the data better than the traditional model for pleural (p = 0.02) but not for peritoneal cancer (p = 0.22). The risk for pleural cancer, rather than showing an indefinite increase, might reach a plateau when a sufficiently long time has elapsed since exposure. The different trends for pleural and peritoneal cancer might be related to clearance of the asbestos from the workers' lungs.

(c) 2008 Wiley-Liss, Inc.
Airborne exposures and risk of gastric cancer: a prospective cohort study. K. Sjödahl, C. Jansson, I.A. Bergdahl, et al. 2007;120(9):2013-8. PubMed · Publisher

Abstract

There is an unexplained male predominance among patients with gastric cancer, and many carcinogens are found in male-dominated dusty occupations. However, the relation between occupational exposures and risk of gastric cancer remains unclear. To investigate whether airborne occupational exposures might influence the risk of noncardia gastric cancer, we used a large, prospective cohort study of male Swedish construction workers. These workers were, during the period 1971-1993, regularly invited to health examinations by a nationwide occupational health service organization. Data on job titles and other variables were collected through self-administered questionnaires and forms completed by the health organization's staff. Industrial hygienists assessed 12 specific airborne occupational exposures for 200 job titles. Gastric cancer, death or emigration occurring during follow-up in 1971-2002 were identified by linkage to the Swedish registers of Cancer, Causes of Death and Total Population, respectively. Incidence rate ratios (IRR) and 95% confidence intervals (CI), adjusted for attained age, tobacco smoking, calendar period and body mass, were derived from Cox regression. Among 256,357 cohort members, contributing 5,378,012 person-years at risk, 948 noncardia gastric cancers were identified. Increased risk of this tumor was found among workers exposed to cement dust (IRR 1.5 [95% CI 1.1-2.1]), quartz dust (IRR 1.3 [95% CI 1.0-1.7]) and diesel exhaust (IRR 1.4 [95% CI 1.1-1.9]). Dose-response relations were observed for these exposures. No consistent positive associations were found regarding exposure to asbestos, asphalt fumes, concrete dust, epoxy resins, isocyanates, metal fumes, mineral fibers, organic solvents or wood dust. In conclusion, this study provides some support to the hypothesis that specific airborne exposures increase the risk of noncardia gastric cancer.

(c) 2007 Wiley-Liss, Inc.
Beyond foreign-body-induced carcinogenesis: impact of reactive oxygen species derived from inflammatory cells in tumorigenic conversion and tumor progression. F. Okada. 2007;121(11):2364-72. Review PubMed · Publisher

Abstract

Foreign-body-induced carcinogenesis is a traditional, maybe old, way of understanding cancer development. A number of novel approaches are available today to elucidate cancer development. However, there are things we learn from the old, and thus I bring out some examples of various clinical cases and experimental models of foreign-body-induced tumorigenesis. What is notable is that the foreign bodies themselves are unrelated to each other, whereas commonly underlying in them is to induce inflammatory reaction, especially stromal proliferation, where those exogenous materials are incorporated and undigested. Such foreign-body-induced carcinogenesis is also recognized in the step of tumor progression, the final step of carcinogenesis that tumor cells acquire malignant phenotypes including metastatic properties. And the phenomenon is universally observed in several cell lines of different origins. In this review I would like to show the evidence that tumor development and progression are accelerated inevitably by inflammation caused from foreign bodies, and that reactive oxygen species derived from inflammatory cells are one of the most important genotoxic mediators to accelerate the process.

(c) 2007 Wiley-Liss, Inc.
Erionite and asbestos differently cause transformation of human mesothelial cells. P. Bertino, A. Marconi, L. Palumbo, et al. 2007;121(1):12-20. PubMed · Publisher

Abstract

Malignant mesothelioma (MM) is an aggressive tumor associated with environmental or occupational exposure to asbestos fibers. Erionite is a fibrous zeolite, morphologically similar to asbestos and it is assumed to be even more carcinogenic. Onset and progression of MM has been suggested as the result of the cooperation between asbestos and other cofactors, such as SV40 virus infection. Nevertheless, several cases of MM were associated with environmental exposure to erionite in Turkey, where SV40 was never isolated in MM specimens. We show here that erionite is poorly cytotoxic, induces proliferating signals and high growth rate in human mesothelial cells (HMC). Long term exposure to erionite, but not to asbestos fibers, transforms HMC in vitro, regardless of the presence of SV40 sequences, leading to foci formation in cultured monolayers. Cells derived from foci display constitutive activation of Akt, NF-kappaB and Erk1/2, show prolonged survival and a deregulated cell cycle, involving cyclin D1 and E overexpression. Our results reveal that erionite is able per se to turn HMC into transformed highly proliferating cells and disclose the carcinogenic properties of erionite, prompting for a careful evaluation of environmental exposure to these fibers. The genetic predisposition to the effect of erionite is a separate subject for investigation.
Polymorphisms of glutathione-S-transferase M1 and manganese superoxide dismutase are associated with the risk of malignant pleural mesothelioma. S. Landi, F. Gemignani, M. Neri, et al. 2007;120(12):2739-43. PubMed · Publisher

Abstract

Individual response to oxidative stress, due to exposure to asbestos fibres plays a significant role in the malignant pleural mesothelioma (MPM) etiology. The differential impact on MPM risk of polymorphic alleles of glutathione-S-transferases (GSTs) and manganese superoxide dismutase (MnSOD/SOD2) genes involved in the defence against oxidative damage has been investigated. Ninety cases of MPM and 395 controls were genotyped using the arrayed-primer extension technique. Logistic regression analysis was applied to assess the predictive role of single nucleotide polymorphisms (SNPs) potentially involved in MPM carcinogenesis after adjustment for potential confounders. An increased risk of MPM was found in subjects bearing a GSTM1 null allele (OR = 1.69, 95% CI = 1.04-2.74; p = 0.034), and in those with the Ala/Ala genotypes at codon 16 within MnSOD (OR = 3.07, 95% CI = 1.55-6.05; p = 0.001). A stronger effect of MnSOD was observed among patients without a clear exposure to asbestos fibres. No effect was found for GSTA2, GSTA4, GSTM3, GSTP1 and GSTT1 genes. These findings, if replicated, contribute substantial evidence to the hypothesis that oxidative stress and cellular antireactive oxygen species systems are involved in the pathogenesis and in the natural history of MPM.
Homozygous deletion of p16INK4a and tobacco carcinogen exposure in nonsmall cell lung cancer. K.S. Kraunz, H.H. Nelson, M. Lemos, et al. 2006;118(6):1364-9. PubMed · Publisher

Abstract

Inactivation of p16(INK4a) in the Rb pathway is among the most common somatic alterations observed in nonsmall cell lung cancers (NSCLCs). While epigenetic inactivation of the p16(INK4a) gene promoter has been shown to be associated with increased tobacco carcinogen exposure, little investigation of any similar association of homozygous deletion or mutation of p16(INK4a) and tobacco use has been completed. In 177 consecutive NSCLCs, we examined the determinants of p16(INK4a) homozygous deletion and mutation, including the pattern of tobacco smoking and asbestos exposure. We observed that p16(INK4a) homozygous deletion occurred at a higher frequency in never smokers as compared to former and current smokers (p = 0.01). This observation suggested that tumors from these patients might be more prone to DNA deletion events; consistent with this, epigenetic silencing of the DNA double-strand break repair genes FancF and BRCA1 was also associated with homozygous deletion of p16(INK4a)(p = 0.002 and p = 0.06, respectively). Finally, mutation of p16(INK4a) was rare and only occurred in patients who were smokers. Hence, the character of somatic alteration in the Rb pathway (deletion, mutation or methylation silencing) in NSCLC is associated with the pattern of tobacco exposure, suggesting that susceptibility to lung cancer is, at least in part, mediated by the biological mechanism that selects for the character of the induced somatic lesion.
Antitumor activity of the intratumoral injection of fowlpox vectors expressing a triad of costimulatory molecules and granulocyte/macrophage colony stimulating factor in mesothelioma. P.L. Triozzi, W. Aldrich, K.O. Allen, et al. 2005;113(3):406-14. PubMed · Publisher

Abstract

Deficiency in costimulatory molecule expression has been implicated in the ability of tumors to escape immune effectors. The activity of the intratumoral administration of recombinant fowlpox vectors expressing a triad of costimulatory molecules (rF-TRICOM) was evaluated in the asbestos-induced AB12 and AC29 mouse models of mesothelioma. Mesothelioma cell infected with rF-TRICOM expressed high levels of the costimulatory molecules. Prolongation of survival was observed in mice receiving rF-TRICOM in AB12 and AC29 intraperitoneal models. Complete tumor regressions were observed in mice receiving intratumoral rF-TRICOM in the AB12 subcutaneous tumor model. Tumor regressions were associated with the development of serum IgG reactivities to mesothelioma-associated determinants and specific systemic cytolytic activity, and responding mice were capable of rejecting tumors upon re-challenge. Antitumor activity was also observed in mice with established AB12 tumor vaccinated with irradiated rF-TRICOM-infected AB12 cells. The antitumor activity of intratumoral rF-TRICOM was superior to that of the intratumoral injection of a fowlpox vector expressing granulocyte-macrophage colony stimulating factor (rF-GM-CSF). AB12 and AC29 tumors were found to produce GM-CSF and to have substantial macrophage infiltration. Production of GM-CSF decreased in vivo in tumors injected with rF-TRICOM. rF-TRICOM and wild-type fowlpox inhibited the growth of AB12 and AC29 cells in vitro; less inhibition was observed with rF-GM-CSF. These results indicate that the intratumoral injection of rF-TRICOM has significant activity in mouse models of mesothelioma and can elicit a systemic antitumor immune response. The results also suggest potential limitations to the intratumoral administration of cytokines, such as GM-CSF, in mesothelioma.
Explaining differences in incidence rates of pleural mesothelioma between Sweden and the Netherlands. A. Burdorf, B. Järvholm, A. Englund. 2005;113(2):298-301. PubMed · Publisher

Abstract

In recent years in several countries a deceleration or leveling off of pleural mesothelioma rates has been observed. The impact of asbestos used was analysed by comparing a country with a relative modest incidence rate of mesothelioma (Sweden) and an early response to asbestos use with a country with one of the highest incidence rates of mesothelioma in Western Europe (The Netherlands). In Sweden the Cancer Register provided information on the annual incidence of pleural mesothelioma, whereas in The Netherlands mortality data were provided by Statistics Netherlands for the period 1969-2001. In The Netherlands among men the incidence rate was consistently higher (1.5-2 times) than in Sweden, whereas among women similar rates were observed. Assuming that none of the female cases was caused by occupational exposure to asbestos, minimum estimates of the etiologic fraction for occupational exposure to asbestos in men would be 82% in Sweden and 92% in The Netherlands. Possible explanations for the consistently higher incidence rates in the Netherlands than in Sweden include differences in exposure levels, the proportion of exposed subjects in the workforce and types of asbestos fibres used. Measures to decrease the exposure to asbestos seem to have decreased the risk of pleural mesothelioma in both countries among age groups below 60 years. This effect will result in a leveling off of the increase in pleural mesothelioma in both countries in the next decade.
Predictions of mortality from pleural mesothelioma in Italy: a model based on asbestos consumption figures supports results from age-period-cohort models. A. Marinaccio, F. Montanaro, M. Mastrantonio, et al. 2005;115(1):142-7. PubMed · Publisher

Abstract

Italy was the second main asbestos producer in Europe, after the Soviet Union, until the end of the 1980s, and raw asbestos was imported on a large scale until 1992. The Italian pattern of asbestos consumption lags on average about 10 years behind the United States, Australia, the United Kingdom and the Nordic countries. Measures to reduce exposure were introduced in the mid-1970s in some workplaces. In 1986, limitations were imposed on the use of crocidolite and in 1992 asbestos was definitively banned. We have used primary pleural cancer mortality figures (1970-1999) to predict mortality from mesothelioma among Italian men in the next 30 years by age-cohort-period models and by a model based on asbestos consumption figures. The pleural cancer/mesothelioma ratio and mesothelioma misdiagnosis in the past were taken into account in the analysis. Estimated risks of birth cohorts born after 1945 decrease less quickly in Italy than in other Western countries. The findings predict a peak with about 800 mesothelioma annual deaths in the period 2012-2024. Results estimated using age-period-cohort models were similar to those obtained from the asbestos consumption model.

(c) 2004 Wiley-Liss, Inc.
Aerodigestive and gastrointestinal tract cancers and exposure to crocidolite (blue asbestos): incidence and mortality among former crocidolite workers. A. Reid, G. Ambrosini, N. de Klerk, et al. 2004;111(5):757-61. PubMed · Publisher

Abstract

The objective of this article was to assess the association between the incidence and mortality from aerodigestive cancers and exposure to crocidolite (blue asbestos). Our study is a cohort study of former workers of the now-defunct crocidolite mining and milling operation at Wittenoom, Western Australia, who have been followed up since 1979 and on whom asbestos exposure and smoking information was known. Standardised mortality and incidence rates were used to compare former workers with the Western Australian male population. Cases were matched with up to 10 randomly assigned controls, and conditional logistic regression was used to examine the relationship between asbestos exposure, smoking status and cancer incidence. There were 129 incident cases from all cancers of interest and 57 deaths. Former workers had a significantly higher risk of mortality from upper aerodigestive cancers than the Western Australian male population. The incidence of upper and lower aerodigestive cancers was higher in the Wittenoom cohort but not significantly so. Cumulative exposure to asbestos did not appear to be associated with the incidence of stomach cancer, colorectal cancer or upper aerodigestive cancers. Smoking status was strongly associated with the incidence of upper aerodigestive cancers, with current smokers experiencing the greatest risk. Our study with longer and more complete follow-up, smoking information and a stronger study design does not show an association between cumulative asbestos exposure and stomach cancer or other gastrointestinal cancers. The excess mortality from upper aerodigestive cancers seen in this cohort of former asbestos workers compared to the Western Australian male population does not appear to be associated with exposure to crocidolite.

Copyright 2004 Wiley-Liss, Inc.
Exposure to cement dust, related occupational groups and laryngeal cancer risk: results of a population based case-control study. A. Dietz, H. Ramroth, T. Urban, et al. 2004;108(6):907-11. PubMed · Publisher

Abstract

A population-based case-control study was performed in the Rhein-Neckar region, Germany, to evaluate occupational risk factors for the development of laryngeal cancer ("Rhein-Neckar-Larynx Study"). Between May 1998 and December 2000, 257 patients (236 males, 21 females), aged 37-80, with histologically confirmed laryngeal cancer, as well as 769 population control persons (702 males, 67 females), were included (1:3 frequency matched by age and sex). History of occupational exposures, as well as other risk factors (tobacco, alcohol), was obtained with face-to-face interviews using a detailed standardized questionnaire. The complete individual work history was assessed. A detailed assessment of work conditions was obtained by job-specific questionnaires (JSQs) for selected jobs known to be associated with exposure to potential laryngeal carcinogens. Estimates for total exposure hours by substance were calculated based on JSQs. Published occupational hygiene data were used to infer semiquantitative scores of exposure intensity for specific job tasks. After adjustment for tobacco and alcohol intake, a significant elevated odds ratios (OR) could be demonstrated for persons that were exposed to cement during their work as building and construction workers. An OR of 2.42 was calculated for workers of the high exposed subgroup (95% confidence interval: 1.14-5.15; p < 0.001). Smoking was the main confounding factor because the unadjusted cement OR of 3.20 dropped down to 2.42 after adjustment for tobacco intake. We conclude that there is good evidence for cement dust exposure acting as a tobacco, alcohol and asbestos independent risk factor for laryngeal carcinoma. Our study gives a base for further toxicologic investigations on this topic.

Copyright 2003 Wiley-Liss, Inc.
Perineal talc exposure and epithelial ovarian cancer risk in the Central Valley of California. P.K. Mills, D.G. Riordan, R.D. Cress, et al. 2004;112(3):458-64. PubMed · Publisher

Abstract

Perineal talc use has been suggested as a possible risk factor for ovarian cancer based on its structural similarity to asbestos, a known human carcinogen. A population-based epidemiologic case-control study of epithelial ovarian cancer (EOC) was conducted in 22 counties of Central California that comprise the reporting area for 2 regional cancer registries. Telephone interviews were conducted with 256 cases diagnosed in the years 2000-2001 and 1,122 controls frequency-matched on age and ethnicity. The interview obtained information on demographic factors, menstrual and reproductive experience, exogenous hormone use, surgical history and family history of cancer. Questions on perineal talc use included frequency of use, duration of use and specific years when talc was used. Multivariate-adjusted odds ratio (OR) and 95% confidence intervals (CI) were derived from unconditional logistic regression. The OR for ever use of talc was 1.37 (CI = 1.02-1.85) compared to never users. However, no dose response association was found. Tubal ligation (TL) modified the effect of talc on EOC such that women with TL had an OR of 0.88 (CI = 0.46-1.68) associated with perineal talc use, whereas women with no TL had an OR of 1.54 (CI = 1.10-2.16). Talc use and EOC risk was highest in women with serous invasive tumors (OR = 1.77; CI = 1.12-2.81). This study provides some support for the hypothesis that perineal talc use is associated with an increased risk of EOC.
Urban mesothelioma: is there an emerging risk of asbestos in place?. V. Ascoli, P. Comba, R. Pasetto. 2004;111(6):975-6. Letter PubMed · Publisher

Summary

In this letter, the authors asked whether asbestos remaining in buildings ("asbestos in place") poses a mesothelioma risk in cities without asbestos industries. They drew on their survey of 167 cytologically or histologically confirmed malignant mesothelioma cases diagnosed in 1993–2001 in Rome, a nonindustrial city, and surrounding municipalities of the Latium region. Exposure history came from a standard questionnaire or medical records. Compared with cases resident outside Rome, cases resident in Rome had a lower percentage of occupational exposure (33.0% vs. 63.0%), a higher proportion of unknown exposure (43.6% vs. 15.1%), and a lower male-to-female ratio for pleural mesothelioma (1.4, 95% CI 1.07–1.91 vs. 3.8, 95% CI 2.79–4.98). Mortality data also showed this lower ratio (1.4 vs. 2.1). In Rome, unknown-exposure cases included almost equal numbers of men and women in non-asbestos-related jobs. The authors noted that sprayed amosite and chrysotile were used extensively in Rome buildings between the 1960s and early 1970s, especially public administration buildings and offices. They also noted that standardized mortality rates from malignant pleural neoplasm in 1980–1997 were higher in Rome than in pooled Latium municipalities (men 0.95 vs. 0.79; women 0.59 vs. 0.39 per 100,000). They inferred that there might be an urban hazard linked to asbestos in place. They recommended revising exposure questionnaires, combining them with lung fibre measurements, and promoting collaborative studies of adequate sample size.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.
Geographic distribution of incident mesothelioma in Connecticut men, 1990-99. A.P. Polednak. 2003;107(3):509-10. Comment · Letter PubMed · Publisher
Incidence trends of mesothelioma in Norway, 1965-1999. B. Ulvestad, K. Kjaerheim, B. Møller, et al. 2003;107(1):94-8. PubMed · Publisher

Abstract

Asbestos exposure is considered to be the only important risk factor for malignant mesothelioma. The importation of asbestos to Norway increased after World War II and peaked in 1970. Stringent regulations took effect in 1977, and importation and use of asbestos practically ended in Norway in the late 1970s, until importation was prohibited in 1982. Our study aimed to analyze the incidence of mesothelioma in Norway according to temporal variation, to study the consequences of the use of asbestos and the asbestos ban effectiveness. An age-period-cohort model was used to analyze time trends for pleural mesotheliomas. From 1965-1999, the annual number of pleural mesotheliomas rose gradually both in males and females, and the highest annual number of pleural mesotheliomas was recorded in 1999 with 73 new cases diagnosed. The age-adjusted log linear drift of malignant mesothelioma of the pleura during the observation period rose 31.1% per 5 years among men and 15.9% among women. In 1995-1999, the age-adjusted incidence rate for men was 16.6 per million person-years for men and 2.3 for women. Cohort-specific risks increased for men born up to around 1935. After this the risks seem to stabilize. The rates were determined by age and by birth cohort. The delayed period effect of the asbestos regulation by the late 1970s will probably have its greatest effects on the mesothelioma rates around 2010.

Copyright 2003 Wiley-Liss, Inc.
Mesothelioma incidence seems to have leveled off in Sweden. K. Hemminki, X. Li. 2003;103(1):145-6. Letter PubMed · Publisher

Summary

In this letter, the authors examined whether the incidence of pleural mesothelioma in Sweden had stopped rising. Sweden had drastically reduced asbestos imports in 1976 and had almost completely abolished asbestos use. The authors therefore expected it to be among the first countries to show a leveling off. They collected cases of pleural mesothelioma (ICD-7 code 162.2) from the Swedish Cancer Registry for 1961–2000 and calculated age-standardized incidence rates, adjusted to the European standard population, in 5-year periods. For men, incidence was 1.82/100,000 (95% CI 1.66–1.99) in 1991–95 and 1.79/100,000 (1.63–1.95) in 1996–2000. For women, the corresponding rates were 0.32 and 0.23/100,000. The rates for the two periods did not differ significantly. The difference in linear regression coefficients for annual rates between 1966–95 and 1996–2000 was reported as highly significant for men. Incidence decreased in the oldest age group, was stable among those aged 45–59, and appeared to increase somewhat among men aged 60–74. Assuming a background rate of 1–2 per million, the authors estimated that 2,030 of 2,190 male cases and about 350 female cases could be ascribed to asbestos up to 2000. They concluded that incidence appeared to have peaked in 1991–95, about 17 years after the reduction in imports. They urged cautious interpretation, because the leveling off might be transient, and called for monitoring of future data.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.
Multiple myeloma and diesel and other occupational exposures in swedish construction workers. W.J. Lee, D. Baris, B. Järvholm, et al. 2003;107(1):134-8. PubMed · Publisher

Abstract

We examined the relationships between occupational exposures and the risk of multiple myeloma among male construction workers in Sweden. A total of 446 myeloma subjects were identified among 365,424 male workers followed from 1971 to 1999. Occupational exposure was assessed using a semiquantitative job-exposure matrix, based on a survey carried out by the Construction Industry's Organization for Working Environment, Occupational Safety and Health in Sweden. Rate ratios (RRs) in the exposed groups relative to the unexposed groups were estimated by Poisson regression. We found an increased risk (RR = 1.3, 95% CI 1.04-1.71) among construction workers exposed to diesel exhaust. Adjustment for other occupational exposures did not change this estimate (RR = 1.3, 95% CI 1.00-1.77). However, there was no monotonic increase in risk with estimated level of exposure (RR for low = 1.4, moderate = 1.1, high = 1.4). There was no evidence of increased risk associated with the other occupational exposures among these construction workers, including asbestos, asphalt, cement dust, metal dust, mineral wool, organic solvents, stone dust and wood dust. Occupational exposure to diesel exhaust in the Swedish construction industry may present a small risk of multiple myeloma, but lack of an exposure-response trend tempers our ability to draw clear conclusions.

Copyright 2003 Wiley-Liss, Inc.
Occupational exposure to dyes, metals, polycyclic aromatic hydrocarbons and other agents and K-ras activation in human exocrine pancreatic cancer. J. Alguacil, M. Porta, T. Kauppinen, et al. 2003;107(4):635-41. PubMed · Publisher

Abstract

ras genes are known critical DNA targets for chemical carcinogens. Exocrine pancreatic cancer (EPC) is the human tumor with the highest prevalence of K-ras mutations at diagnosis. We analyzed the relationship between past occupational exposure to dyes, metals, polycyclic aromatic hydrocarbons (PAHs) and other agents and mutations in codon 12 of the K-ras gene in 107 incident cases of EPC. Information on occupational and life-style factors was obtained from personal interviews conducted during hospital stay. Occupational exposures were examined using industrial hygienists (IH) assessment and the Finnish job-exposure matrix (Finjem). Specific occupational exposures among K-ras mutated EPC cases (n = 83) were compared to those of K-ras wild-type EPC cases (n = 24) (case-case analysis). Multivariate-adjusted odds ratios (OR) and their corresponding 95% confidence limits were estimated by unconditional logistic regression. Cases with K-ras mutations were significantly more likely than wild-type cases to have been exposed to dyes and organic pigments (OR 4.8; p<0.05). There was some indication of weaker associations between K-ras mutations and occupational exposure to lead, PAHs, benzo[a]pyrene, gasoline, nickel, inhalatory exposure to chromium and sedentary work. The association with chromium compounds was stronger for G to T transversions, a finding compatible with experimental studies on mutation spectra for chromium. Results lend moderate support to the hypothesis of indirect relationships between occupational exposure to dyes and organic pigments and the activation of the K-ras gene in the etiopathogenesis of human exocrine pancreatic cancer.

Copyright 2003 Wiley-Liss, Inc.
Aberrant methylation of the CDKN2a/p16INK4a gene promoter region in preinvasive bronchial lesions: a prospective study in high-risk patients without invasive cancer. A. Lamy, R. Sesboüé, J. Bourguignon, et al. 2002;100(2):189-93. PubMed · Publisher

Abstract

Among the identified factors involved in malignant transformation, abnormal methylation of the CDKN2A/p16(INK4a) gene promoter has been described as an early event, particularly in bronchial cell cancerization. Precancerous bronchial lesions (n = 70) prospectively sampled during fluorescence endoscopy in a series of 37 patients at high risk for lung cancer were studied with respect to the methylation status of the CDKN2A gene. Methylation-specific polymerase chain reaction was performed on DNA extracted from pure bronchial cell populations derived from biopsies and detection of p16 protein was studied by immunohistochemistry on contiguous parallel biopsies. Aberrant methylation of the CDKN2A gene promoter was found in 19% of preinvasive lesions and its frequency increased with the histologic grade of the lesions. Methylation in at least 1 bronchial site was significantly more frequent in patients with cancer history, although there was no difference in the outcome of patients with or without methylation in bronchial epithelium. The other risk factors studied (tobacco and asbestos exposure) did not influence the methylation status. There was no relationship between CDKN2A methylation and the evolutionary character of the lesions. Our results confirm that abnormal methylation of the CDKN2A gene promoter is an early event in bronchial cell cancerization, which can persist for several years after carcinogen exposure cessation, and show that this epigenetic alteration cannot predict the evolution of precancerous lesions within a 2-year follow-up.

Copyright 2002 Wiley-Liss, Inc.
Survival in operable non-small-cell lung cancer: role of p53 mutations, tobacco smoking and asbestos exposure. T. Sioris, K. Husgafvel-Pursiainen, A. Karjalainen, et al. 2000;86(4):590-4. PubMed · Publisher

Abstract

Validated markers are needed to identify operable lung cancer patients with poor prognosis. About one-half of non-small-cell lung cancers (NSCLCs) carry a mutation in the p53 tumor-suppressor gene. We examined 101 NSCLC patients for surgical stage, completeness of resection, tobacco smoking, asbestos exposure, age, gender and p53 gene mutations as prognostic factors after a follow-up period of 4 years. Cox's multivariate regression model was applied to quantify the associations with overall and cancer-related survival. Patients with a wild-type p53 gene had an overall 4-year survival of 43% and those with a mutated p53 gene, 35%. In squamous-cell carcinoma, stage and heavy smoking, defined as the median of pack-years smoked, had prognostic significance for overall survival. Only stage was associated with poor cancer-related survival. Asbestos exposure was not associated with overall survival or cancer-related survival in squamous-cell carcinoma or adenocarcinoma. In adenocarcinoma, p53 mutation, in addition to stage, emerged as a significant predictor of poor cancer-related survival.

Copyright 2000 Wiley-Liss, Inc.

1990s

Vitamin A and cancer prevention I: observations in workers previously exposed to asbestos at Wittenoom, Western Australia. A.W. Musk, N.H. de Klerk, G.L. Ambrosini, et al. 1998;75(3):355-61. PubMed · Publisher

Abstract

Our aim was to describe a vitamin A-based cancer prevention program for former asbestos workers and to check for possible harmful effects by comparing rates of disease and death in study subjects with subjects who chose not to join. All subjects had been occupationally exposed to crocidolite at Wittenoom Gorge between 1943 and 1966; 1,677 subjects indicated interest in the program and 1,203 joined between June 1990 and May 1995. Comparison subjects consisted of 996 former workers known to be alive in Western Australia in 1990 who did not join the program. Program subjects were provided with annual supplies of vitamin A (either synthetic beta-carotene or retinol), help in quitting smoking and dietary advice. The comparison group received only mail contact. Both groups were followed up to December 1994 for vital status and cancer information, and rates of cancer and death from various causes were compared. Mortality in both groups was higher than expected (standardised mortality ratio 1.23 in program subjects and 1.67 in comparison subjects). After adjustment for age, smoking and asbestos exposure, the relative rates in participants compared with non-participants was below I for all examined cancers and causes of death. For mesothelioma and lung cancer, group differences increased with time from entry, whereas other differences dissipated with time. No significant side effects were reported. In conclusion, program participants had significantly lower mortality than non-participants, but the rates of the 2 groups converged with time.
Vitamin A and cancer prevention II: comparison of the effects of retinol and beta-carotene. N.H. de Klerk, A.W. Musk, G.L. Ambrosini, et al. 1998;75(3):362-7. Randomized trial PubMed · Publisher

Abstract

Former blue asbestos workers known to be at high risk of asbestos-related diseases, particularly malignant mesothelioma and lung cancer, were enrolled in a chemo-prevention program using vitamin A. Our aims were to compare rates of disease and death in subjects randomly assigned to beta-carotene or retinol. Subjects were assigned randomly to take 30 mg/day beta-carotene (512 subjects) or 25,000 IU/day retinol (512 subjects) and followed up through death and cancer registries from the start of the study in June 1990 till May 1995. Comparison between groups was by Cox regression in both intention-to-treat analyses and efficacy analyses based on treatment actually taken. Median follow-up time was 232 weeks. Four cases of lung cancer and 3 cases of mesothelioma were observed in subjects randomised to retinol and 6 cases of lung cancer and 12 cases of mesothelioma in subjects randomised to beta-carotene. The relative rate of mesothelioma (the most common single cause of death in our study) for those on retinol compared with those on beta-carotene was 0.24 (95% CI 0.07-0.86). In the retinol group, there was also a significantly lower rate for death from all causes but a higher rate of ischaemic heart disease mortality. Similar results were found with efficacy analyses. Our results confirm other findings of a lack of any benefit from administration of large doses of synthetic beta-carotene. The finding of significantly lower rates of mesothelioma among subjects assigned to retinol requires further investigation.
Transfection of the gene for B7-1 but not B7-2 can induce immunity to murine malignant mesothelioma. C.C. Leong, J.V. Marley, S. Loh, et al. 1997;71(3):476-82. PubMed · Publisher

Abstract

Transfection of the genes encoding the co-stimulatory molecules B7-1 and B7-2 has enhanced the development of immunity to a variety of experimental tumors, although most of these were inherently immunogenic. We have determined the effect of expression of these genes on the induction of immunity to 2 non-immunogenic murine malignant mesothelioma (MM) cell lines (AC29 and AB1). We had previously shown that B7-1 transfection into AC29 delayed but did not prevent tumor development by certain of the transfectant clones. Here we demonstrate that over-expression of B7-1 can inhibit tumor development by certain AB1-B7-1 clones, that inhibition of transfectant growth is dependent on CD4+ and CD8+ T cells and that mice that reject some of these transfectant clones are capable of rejecting subsequent inocula of the parental cell line, AB1. The transfectant clones can generate tumor-specific cytotoxic T cells. By contrast, expression of B7-2 in several clones derived from either AB1 or AC29 had no significant effect on the development of tumors in vivo. Our data are consistent with data from other systems that show differences in the effect of modification by B7-1 or B7-2 on the modulation of anti-tumor immune responses. They demonstrate that such modifications can induce protective immunity against an MM cell line but confirm the intra- and inter-tumoral heterogeneity in the effect of genetic modification on the induction of immunity. Our observations are relevant to human MM because these cell lines have been derived from asbestos-induced tumors and share many properties with human cell lines of the same histological type.
International renal-cell cancer study. IV. Occupation. J.S. Mandel, J.K. McLaughlin, B. Schlehofer, et al. 1995;61(5):601-5. PubMed · Publisher

Abstract

The relationship between renal-cell cancer (RCC) and occupation was investigated in an international multicenter population-based case-control study. Study centers in Australia, Denmark, Germany, Sweden and the United States interviewed 1732 incident RCC cases and 2309 controls. Significant associations were found with employment in the blast-furnace or the coke-oven industry [relative risk (RR), 1.7; 95% confidence interval (CI), 1.1-2.7], the iron and steel industry (RR, 1.6; 95% CI, 1.2-2.2) and exposure to asbestos (RR, 1.4; 95% CI, 1.1-1.8), cadmium (RR, 2.0; 95% CI, 1.0-3.9), dry-cleaning solvents (RR, 1.4; 95% CI, 1.1-1.7), gasoline (RR, 1.6; 95% CI, 1.2-2.0) and other petroleum products (RR, 1.6; 95% CI, 1.3-2.1). Asbestos, petroleum products and dry-cleaning solvents appear to merit further investigation, in view of the relationship between risk and duration of employment or exposure and after adjustment for confounding. There was a negative association between RCC and education, but it was not consistent across all centers. Overall, the results of our multicenter case-control study suggest that occupation may be more important in the etiology of RCC than indicated by earlier studies.
Lung adenocarcinoma and indicators of asbestos exposure. F. Mollo, E. Pira, G. Piolatto, et al. 1995;60(3):289-93. PubMed · Publisher

Abstract

A case-control study was carried out on 145 male lung-cancer patients diagnosed at autopsy and 178 controls, in order to investigate the relationship between asbestos exposure and the cell type of pulmonary carcinoma. Adenocarcinomas (AD) were individually matched with other cell types and with controls. The relative risk (RR) of developing AD in relation with lung asbestos body (AB) content as the exposure indicator was calculated by using logistic-regression analysis for matched sets. Two cutoff levels, 1,000 and 10,000 asbestos bodies per gram dry weight (AB/gdw), were used in the analysis. In addition, AB counts were treated as a continuous variable (log AB+I). A significant association was found between AD and asbestos exposure, using levels and logarithmic transformation. However, an association of asbestos exposure with cell types other than AD could not be ruled out.
Trends in incidence of pleural mesothelioma in the Rotterdam area. R.A. Damhuis, H.T. Planteydt. 1995;60(6):883. Letter PubMed · Publisher

Summary

This letter to the editor asked whether the rising incidence of pleural mesothelioma in the Rotterdam area of the Netherlands had come to an end. The authors noted that, despite protective measures, incidence had continued to rise because of the long latency period of 20 to 50 years between asbestos exposure and diagnosis. Data came from the Rotterdam Cancer Registry, which covers the industrial and shipping region of the southwestern Netherlands. Registration had been complete since 1987 in the central part of the region, which has about 1.5 million inhabitants. For 1987-1992 the authors calculated age-specific and age-standardized (world standard) incidence rates, using population data from the Central Bureau of Statistics. They excluded patients whose diagnosis was based on clinical information only (10%) and those whose pathology reports did not clearly specify malignant mesothelioma (4%). Trends were evaluated with linear regression. In total, 375 patients were diagnosed with pleural mesothelioma. In men, the age-standardized incidence per 100,000 rose from 5.2 in 1987-1989 to 6.0 in 1990-1992. There were small increases in men aged 45-59 and 60-74 and a strong increase in men aged 75 and over. Women (28 cases) and younger age groups (3 cases) were not evaluated because the numbers were small. The authors concluded that the peak of mesothelioma incidence had not yet been reached. They noted that in 2 cities in the area mesothelioma made up more than 3% of overall mortality in men, and that preventive measures produce results only after many years.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.
Asbestos and erionite fibres can induce mutations in human lymphocytes that result in loss of heterozygosity. K. Both, D.W. Henderson, D.R. Turner. 1994;59(4):538-42. PubMed · Publisher

Abstract

Although asbestos and erionite are proven human carcinogens, most studies have concluded that these fibres are not mutagenic to mammalian cells in vitro. We have studied the potential of these fibres and chrysotile fibres to induce mutations in human peripheral lymphocytes, using a mutation assay that measures mutation at the autosomal HLA-A locus. Exposure of lymphocytes in culture to 400 micrograms/ml of crocidolite or erionite for 72 hr did not result in a statistically significant increase in the mutation frequency (MF) in the HLA-A assay, although a trend towards increased MF was observed. Exposure to 400 micrograms/ml chrysotile resulted in no increase in MF; however a significant increase was observed at 50 micrograms/ml. Mutations in somatic cells can be classified according to their molecular basis. Molecular analysis of mutants obtained following exposure of lymphocytes to crocidolite and erionite demonstrated a statistically significant increase in the class of mutations arising from loss-of-heterozygosity (LOH) events involving the selection locus (HLA-A) and more distal loci. Mutations following exposure to crocidolite and erionite showed a greater frequency of LOH than did spontaneous mutants (p < 0.02 and p < 0.005 respectively). Mutants following exposure to chrysotile did not display a significant difference in LOH when compared with spontaneous mutants. Thus, although an increase in overall mutation frequency following fibre exposure did not achieve statistical significance, the modest increase seen following exposure to erionite and crocidolite is translated into a highly significant change in those components of the spectrum of mutations which result in LOH.
Residential radon exposure and lung cancer--an epidemiological study of Norwegian municipalities. K. Magnus, A. Engeland, B.M. Green, et al. 1994;58(1):1-7. PubMed · Publisher

Abstract

The study is based on a collaboration between the Cancer Registry of Norway, the Norwegian Radiation Protection Authority, and National Radiological Protection Board (NRPB, UK). The association between indoor radon exposure and lung cancer was studied in 427 municipalities. NRPB detectors were sent to 10,000 households, and 7,500 of the detectors were returned. Data from a nation-wide survey of smoking habits in 1964-1965 were available. Data on asbestos exposure were also used in a regression analysis. The reporting to the Cancer Registry of all new cases of cancer is fairly complete, as hospital departments and institutes of pathology are obliged to report all cancer cases. The histologically confirmed lung cancer cases were grouped into squamous-cell carcinoma, small-cell carcinoma, adenocarcinoma and other or non-specified histological types. The age-adjusted rate of lung cancer by histological type was the dependent variable in the regression analysis. A consistent increase in incidence of lung cancer was seen with increasing tobacco consumption, but no positive trend could be shown with increasing radon exposure in the descriptive presentation of the data. In the regression analysis, however, the incidence of small-cell anaplastic lung tumors in females increased significantly with increasing radon exposure. When based on the regression coefficients, the fraction of lung cancers attributable to radon is about 2-4%. However, systematic errors cannot be excluded in an ecological study such as presented here.
In vitro effects of recombinant human interferon gamma on human mesothelioma cell lines. L. Zeng, A. Buard, I. Monnet, et al. 1993;55(3):515-20. PubMed · Publisher

Abstract

Malignant mesothelioma is a tumor arising from serous surfaces and often related to asbestos exposure. Malignant mesothelioma is resistant to various forms of therapy. Radiotherapy, surgery or chemotherapy only slightly improve prognosis. IFN-gamma produces complete or partial responses in stage-I patients with malignant mesothelioma. The in vitro biological effect of IFN-gamma on malignant mesothelioma cells remains poorly elucidated. In the present study, 32 well-characterized human mesothelioma cell lines (HMCL) were treated with r-hu IFN-gamma at 4 doses and cell growth was determined by a colorimetric method (MTT assay). Among the 32 HMCLs tested, II exhibited significant cell-growth inhibition; 16 were insensitive to r-hu IFN-gamma, and 5 were slightly inhibited. The sensitive cell lines were strongly inhibited by r-hu IFN-gamma. Our results show that HMCL exhibit a large range of responses to r-hu IFN-gamma, some of which can be compared with those obtained in vivo in humans.
K-ras mutations in human adenocarcinoma of the lung: association with smoking and occupational exposure to asbestos. K. Husgafvel-Pursiainen, P. Hackman, M. Ridanpää, et al. 1993;53(2):250-6. PubMed · Publisher

Abstract

We investigated point mutational activation of the ras genes (K-ras codons 12, 13 and 61; N-ras codons 12, 13 and 61; H-ras codons 12 and 61) in primary, resected lung cancer by dot blotting and oligonucleotide hybridization. K-ras mutations were found in 14 (29%) of the 48 lung tumour specimens examined, but no N-ras or H-ras mutations were found. The highest frequency of K-ras mutation was observed in adenocarcinoma: 12 of the 21 samples studied (57%) had a mutation, which is one of the highest frequencies reported for lung adenocarcinoma. The commonest type of mutation in these lung tumour samples consisted of transversions: we observed 11, of which 8 (57% of all mutations) were G to T transversions. Most of the 48 patients studied had a history of heavy smoking, either with or without evidence of occupational exposure to asbestos. Statistical analysis revealed--in addition to the highly significant association between the adenocarcinoma type of lung cancer and K-ras mutation--a clear association of K-ras mutations with heavy life-time smoking (> or = 50 pack-years of cigarette smoking; odds ratio (OR) 4.9, 90% CI 1.2-19.5, multivariate analysis). In addition, occupational asbestos exposure showed an elevated, but non-significant, OR of 2.2 (90% CI 0.6-8.7) with the presence of K-ras mutation. We conclude that the occurrence of K-ras mutations in adenocarcinoma of the lung is frequent, and that such mutations are associated with heavy life-time exposure to tobacco smoke, possibly in combination with occupational exposure to asbestos fibres.
Malignant mesothelioma after environmental exposure to blue asbestos. J. Hansen, N.H. de Klerk, J.L. Eccles, et al. 1993;54(4):578-81. PubMed · Publisher

Abstract

To determine the magnitude of the population at risk from non-occupational exposure to crocidolite at Wittenoom, Western Australia (WA), a cohort of 4,890 residents who never worked for the mining company Australian Blue Asbestos (ABA) has been assembled from all 18,553 available records: the local school register, hospital attendances, the WA electoral roll, birth certificates, workers who answered a mailed questionnaire in 1979, participants in a cancer-prevention programme using vitamin-A dietary supplements, and other sources. The majority of subjects were relatives and friends of ABA employees, and nearly half the cohort were either born at Wittenoom or first went there as children under 10 years of age. As most residents were at Wittenoom when the mine and mill were in operation during the period 1943 to 1966, 82% were first exposed to crocidolite 20 or more years ago. The proportion of other workers (i.e., not employed by ABA) and their families increased once the mining operations ceased. To date, 24 cases of mesothelioma have been reported in this cohort: 9 males and 15 females. Time from first exposure to diagnosis ranged from 23 to 44 years and residence in Wittenoom ranged from 6 weeks to 11 years.
Establishment of a murine model of malignant mesothelioma. M.R. Davis, L.S. Manning, D. Whitaker, et al. 1992;52(6):881-6. PubMed · Publisher

Abstract

Malignant mesothelioma (MM) is an aggressive tumour of the serosal cavities which is associated with previous asbestos exposure and is generally found to be resistant to conventional forms of therapy. Adequate scientific and clinical assessment of this disease has been severely limited by the relatively low incidence of mesothelioma and the lack of representative cell lines and animal models. The purpose of this study was to develop an asbestos-induced murine model of MM both as an in vivo-passaged malignancy and as in vitro-established cell lines. Such a model system would be invaluable for use in the study of various cellular, molecular and genetic aspects of the disease, and for the pre-clinical evaluation of potential therapeutic agents. BALB/c and CBA mice were injected intraperitoneally with crocidolite asbestos. Seven to 25 months after exposure, 35% of the mice developed mesothelioma (5 BALB/c, 9 CBA), as determined by standard cytological and histological parameters. From these primary tumours, 12 continuously growing cell lines (5 BALB/c, 7 CBA) were established in culture. All have been confirmed as mesothelioma by cytological and ultrastructural (electron microscopy) analyses. These lines have been in culture for 7 to 24 months and have achieved passages above 32 (range 32 to 106). As in the human disease, the murine mesothelioma lines vary in their morphology and growth rates (doubling times ranging from 14 to 30 hr). All cell lines produced tumours when injected into syngeneic mice.
Mesothelioma in rats following intrapleural injection of chrysotile and phosphorylated chrysotile (chrysophosphate). A. Van der Meeren, J. Fleury, M. Nebut, et al. 1992;50(6):937-42. PubMed · Publisher

Abstract

Pathological effects of asbestos are probably dependent on the size and surface properties of the fibers. Surface-modified chrysotile fibers were injected into the pleural cavity of rats to investigate the potency of the fiber to induce mesothelioma. Chrysotile fibers were modified by a phosphorylation process, resulting in the presence of phosphorus at the fiber surface. Phosphorylated samples were characterized by enhanced durability and reduced affinity for biological macromolecules. Five samples were tested: 1 untreated and 4 phosphorylated. ChrP1, ChrP2 and ChrP3 corresponded to phosphorylated samples obtained by first, second and third passages through an Alpine classifier; Pm was defibrillated ChrP1. The number of fibers per microgram and the size distribution were determined by transmission electron microscopy and classified in 4 size groups. Groups of 35 rats were inoculated with 20 mg of fibers suspended in 0.9% NaCl solution. No mesothelioma was found in the saline controls. All fiber samples were proficient in producing mesothelioma; the percentages were different between groups and untreated chrysotile but not significantly so. The differences may be explained on the basis of the number of fibers injected which were greater than 8 microns in length and less than 0.25 microns in diameter. The findings of a proficiency of long fibers to produce mesothelioma, previously reported by others for glass fibers, could be applied to chrysotile.
Serum oncoproteins and growth factors in asbestosis and silicosis patients. P.W. Brandt-Rauf, S. Smith, K. Hemminki, et al. 1992;50(6):881-5. PubMed · Publisher

Abstract

Levels of 9 different oncoproteins and growth factors were assayed by immunoblotting with monoclonal antibodies in 91 serum samples collected between March 1983 and August 1987 from 46 pneumoconiosis patients (36 asbestosis, 10 silicosis) at high risk for the development of cancer. Follow-up of these patients through June 1991 showed that 18 had developed cancer (11 lung, 2 pleural mesothelioma, 2 transitional-cell carcinomas of the urinary bladder, 1 osteosarcoma, 1 non-Hodgkin's lymphoma, 1 adenocarcinoma of the gallbladder). Increased serum levels of ras oncogene-related protein (p21) were found in 7 of the 18 patients who developed cancer (5 lung, 2 pleural mesothelioma) versus 2 of the 28 patients without cancer, a statistically significant difference (p = 0.012). In addition, 6 of the 7 p21-positive cancer cases had positive serum samples prior to clinical diagnosis of disease (average = 16.3 months, range = 3-26 months prior to diagnosis), suggesting that elevated serum p21 levels may be a useful marker for earlier detection in a significant percentage of respiratory malignancies. Finally, elevated serum levels of PDGF-related protein were detected significantly more frequently in advanced pneumoconiosis cases (ILO radiographic classification of 2/1 or greater) than in less advanced cases (80% vs. 41.9%; p = 0.016), and there was a tendency for these PDGF-positive patients to have progression of their disease (68.2% vs. 41.7%; p = 0.065), suggesting that elevated serum PDGF levels may be a marker for the development of severe and progressive pneumoconioses.
Establishment and characterization of five human malignant mesothelioma cell lines derived from pleural effusions. L.S. Manning, D. Whitaker, A.R. Murch, et al. 1991;47(2):285-90. PubMed · Publisher

Abstract

Malignant mesothelioma (MM) is an aggressive tumour of the serosal cavities which is associated with exposure to asbestos. Studies of this tumour have been limited by a paucity of well-characterized human MM cell lines. In this study, 5 human MM cell lines were established from pleural effusions of patients with this malignancy. All 5 patients were males with known crocidolite asbestos exposure, who had received no treatment for their disease and in whom the diagnosis was confirmed by cytology, histology and electron microscopy (EM). These lines have been in culture from 11 to 25 months, and all of them for more than 18 passages. The appearance of the cells in culture was extremely varied; in 3 of the lines they were spindle-shaped with few vacuoles (JU77, LO68 and ONE58); in 1 line they had a thick, stellate shape with vacuoles (NO36) and in 1 they were very pleomorphic in both shape and size with irregular membranes and numerous vacuoles [DeH128 (M)]. Upon reaching confluence, cells in 3 of the 5 lines assumed the cobblestone-like pattern characteristic of epithelial-type cells, whereas in the other 2 (LO68 and ONE58) they remained spindle-shaped. All 5 lines demonstrated a loss of contact inhibition (i.e., piling) at confluence. Minimum doubling times varied significantly from 18 hr (JU77) to more than 30 hr [DeH128 (M)]. Cytological examination showed characteristic mesothelial/mesothelioma morphology, and epithelial membrane antigen (EMA) and cytokeratin were demonstrated in cells from all 5 lines. These cells lacked CEA and epithelial mucin. The presence of cell junctions, glycogen and numerous long, thin, branching microvilli was readily demonstrable by EM. All lines had abnormal karyotypes, with the modal chromosome number varying from 40 to 80. Variable chromosome numbers, numerous structural rearrangements and unrecognizable marker chromosomes were readily observed; however, the only consistent change seen was del 6q21 in 4 of the 5 lines. The establishment of these 5 cultured human MM cell lines now provides an opportunity for comparative study of several aspects of the biology of MM in vitro as well as screening new treatment modalities.
Asbestos exposure and histologic cell types of lung cancer in surgical and autopsy series. F. Mollo, G. Piolatto, D. Bellis, et al. 1990;46(4):576-80. PubMed · Publisher

Abstract

A case-control study was carried out on 41 surgical and 106 autopsy histological tissue samples of lung cancer in men, in order to investigate the relationships between asbestos exposure and cell type of pulmonary carcinoma. Both occupational history (obtained by interviews of surgical patients or of the next-of-kin for deceased subjects) and lung asbestos body content (determined by optical count after hypochlorite digestion and membrane filtration of lung tissues) were considered as asbestos exposure indicators. No significant relationships were found in the surgical series after adjustment for smoking. The autopsy series showed a trend towards an association between lung adenocarcinoma and asbestos exposure indicators and a markedly higher agreement between the 2 kinds of indicators than that observed in the surgical series.

1980s

A case-control study of multiple myeloma nested in the American Cancer Society prospective study. P. Boffetta, S.D. Stellman, L. Garfinkel. 1989;43(4):554-9. PubMed · Publisher

Abstract

Among the subjects enrolled in the American Cancer Society Cancer Prevention Study II, a large nation-wide prospective study, 282 died from multiple myeloma (MM) during the first 4 years of follow-up. These were divided into incident cases who were initially free from disease and prevalent cases who reported MM or related symptoms at the time of enrollment. For each case, 4 controls matched for age, sex, ethnic group and residence were randomly selected. Previous history of diabetes [odds ratio (OR) = 2.0] and employment as farmer (OR = 2.7) were the risk factors consistently suggested by the results of the analysis. The risk associated with farming showed a linear trend with duration of exposure. Pesticide or herbicide exposure was not a risk factor per se but, when combined with farming, it increased the OR to 4.3. Low education, occupational exposure to dyes, and employment in a bank, on the railroad or as a maid were also suggested risk factors, but either they were not statistically significant or they were based on small numbers of exposed subjects. No association between MM and asbestos exposure was observed.
Survival patterns for malignant mesothelioma: the SEER experience. R. Spirtas, R.R. Connelly, M.A. Tucker. 1988;41(4):525-30. PubMed · Publisher

Abstract

Statistical analyses of 1,475 histologically confirmed cases of malignant mesothelioma ascertained through the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute for the years 1973-1984 showed age at diagnosis, sex, stage of disease, type of treatment, and geographic area of residence to be important predictors of patient survival, although type of treatment may be confounded with prognostic factors (patients selected for surgical treatment tended to have better performance status than other patients). Women below the age of 50 had an unusually long survival, even after adjustment for the effects of other variables in the model. A relatively large proportion of female cases had site of disease designated as peritoneum, but site was not a significant prognostic factor. These results suggest that age, gender and stage of disease should be carefully considered in designing and analyzing clinical trials for persons with mesothelioma. Survival was shorter in the 4 SEER registries which had shipbuilding as a major industry than in the others with less potential asbestos exposure, offering weak support for the hypothesis that asbestos-exposed cases of mesothelioma have worse survival experience than other cases.
Morphology of bronchogenic carcinoma in workers formerly exposed to crocidolite at Wittenoom Gorge in Western Australia. J.E. Baker, D.C. Reutens, D.F. Graham, et al. 1986;37(4):547-50. PubMed · Publisher

Abstract

Cytology and histology material from 46 bronchogenic carcinomas occurring in ex-workers from the Wittenoom crocidolite mine and mill in Western Australia and a matched random sample of 234 other bronchogenic carcinomas occurring in Western Australia over the same period were reviewed by a single histopathologist without knowledge of asbestos exposure status. Squamous-cell carcinomas formed 45.7% of the cancers in the asbestos-exposed group but only 32.5% of the cancers in the comparison group. This difference could not be explained by differences in smoking history between the two groups of lung cancer patients or in the type of histopathological material available for review. The excess of squamous-cell cancers was observed in subjects both with and without parenchymal asbestosis.
Proportion of lung cancers due to occupational exposure. U. Pastorino, F. Berrino, A. Gervasio, et al. 1984;33(2):231-7. PubMed · Publisher

Abstract

The proportions of male lung cancers due to occupational exposure and, respectively, to cigarette smoking in a highly industrialized area of Northern Italy were estimated in a population-based case-control study in 1976-9. Two hundred and four out of the 211 lung cancer cases and 351 controls sampled from the source population were questioned about their occupational and smoking histories. On the basis of the occupational history each subject was classified as probably exposed (+), possibly exposed (?), or unexposed (-) to one or more of the chemicals known to be carcinogenic for the human lung, namely asbestos, polycyclic aromatic hydrocarbons, arsenic, nickel and chromium compounds, BCME, CMME and vinyl chloride. Upon stratification by cigarette smoking, contrasting the occupationally exposed subjects, whether certainly or uncertainly defined, with the unexposed ones, the RR for lung cancer was 2.1 and the occupational etiologic fraction was 0.33 (95% confidence interval 0.19-0.47). The tobacco etiologic fraction was 0.81, while the two exposures together accounted for 89% of the total burden of incident cases. If 33% of all male lung cancers were of occupational aetiology, then this alone would represent 5% of all cancer deaths.
Cellular ingestion, toxic effects, and lesions observed in human bronchial epithelial tissue and cells cultured with asbestos and glass fibers. A. Haugen, P.W. Schafer, J.F. Lechner, et al. 1982;30(3):265-72. PubMed · Publisher

Abstract

Although exposure to asbestos has been shown in previous epidemiological studies to synergistically increase the risk of bronchogenic carcinoma for cigarette smokers, the pathobiological mechanism(s) responsible for the cocarcinogenic action of asbestos is not known. Therefore, the effects of asbestos fibers on normal human tracheobronchial epithelium are of interest. Asbestos fibers, i.e., amosite, crocidolite and chrysotile (UICC samples) and glass fibers were initially assayed for their cytotoxicity. Bronchial epithelial cells exposed to either asbestos or glass fibers displayed inhibition of cell growth as a function of fiber concentration. When compared to glass fibers, asbestos fibers caused a statistically significant (p<0.05) decrease in cell population doubling rate. Chrysotile was approximately 10 times more cytotoxic than either amosite or crocidolite and more than 100 times more cytotoxic than the glass fibers. Epithelial cells were 10 to 15 times more sensitive to the cytotoxic effects of asbestos fibers than bronchial fibroblasts from the same donor. Using electron microscopy, asbestos fibers were seen to be ingested by epithelial cells. After exposure for 2 h short fibers (<12 µm) were found both in the cytoplasm and within phagosomes. High-voltage electron microscopy combined with stereo-microscopy revealed asbestos fibers in the cytoplasmic matrix. A single exposure to amosite asbestos (100-1000 µg/ml) was found to induce focal hyperplasia and epidermoid metaplasia with cellular atypia in human tracheobronchial explants. Surface fine structure observations revealed asbestos fibers protruding from these lesions. Intra-cytoplasmic and intranuclear fibers of amosite were identified in these focal lesions using X-ray microanalysis in combination with transmission electron microscopy. With increasing time, fibers were also seen deposited within the submucosa of the explants. The preferential cytotoxicity of asbestos for epithelial cells and the metaplastic response of bronchial epithelium may be important in the cocarcinogenic action of asbestos.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

1970s

Enhancement by asbestos of oncogenesis by Moloney murine sarcoma virus in CBA mice. K. Kanazawa, T. Yamamoto, Y. Yuasa. 1979;23(6):866-74. PubMed · Publisher

Abstract

Five micrograms of finely ground crocidolite asbestos (UICC standard sample) were injected intraperitoneally into 3-week-old CBA mice, together with 10(5) FFU of Moloney murine sarcoma virus. Altogether 44 out of 61 mice (72.1%) so treated developed palpable intraperitoneal tumours, and half of these died of such tumours within 100 days. The same amount of quartz and carbon similarly administered gave lower tumour incidences, namely, 19.4% (3.2% fatal) and 11.9% (1.5% fatal) respectively. Only 1 out of 59 mice inoculated with the virus alone developed a palpable intraperitoneal tumour, and this regressed spontaneously within 10 days of its first appearance. No tumours were encountered in mice treated with either asbestos, quartz or carbon alone. All the neoplasms had the appearance, under the light microscope, of anaplastic sarcomas. Most of them were confined to the serosal surface of the abdominal cavity, although invasion of underlying tissues was observed in some of the animals that died. Electron microscopical examination of tumours revealed the presence of C-type particles budding off from cellular surface. Some neoplastic cells showed characteristic features of mesothelial lining cells. The role of milky spots (taches laiteuses) in oncogenesis by asbestos and virus, especially in the induction of mesothelioma, is discussed.
Milky spots (Taches laiteuses) as structures which trap asbestos in mesothelial layers and their significance in the pathogenesis of mesothelial neoplasia. K. Kanazawa, F.J. Roe, T. Yamamoto. 1979;23(6):858-65. PubMed · Publisher

Abstract

The UICC standard sample of asbestos, crocidolite, was injected subcutaneously into the flanks of CBA/lac mice. Asbestos fibres were found in milky spots in the serosal cavities more than 442 days after the injection, in the form of either naked fibres or asbestos bodies. Milky spots were the only structure in which asbestos fibres were observed in the mesothelial layer. The fact that asbestos fibres were found in the liver, spleen, kidney, brain, etc., in addition to milky spots, suggested that they were transported by the blood stream throughout the body. This assumption was confirmed by the similar distribution of asbestos after intravenous administration. The vascular and cellular structure of milky spots is such that they are particularly likely to trap blood-borne asbestos fibres. Hyperplastic changes were observed in milky spots after both subcutaneous and intravenous administration of asbestos in mice. The possible involvement of milky spots in the genesis of tumors of the mesothelium following exposure of animals to asbestos is discussed.
The effect of fibre size on the in vitro biological activity of three types of amphibole asbestos. R.C. Brown, M. Chamberlain, D.M. Griffiths, et al. 1978;22(6):721-7. PubMed · Publisher

Abstract

Three standard (UICC) samples of amphibole asbestos were subjected to ball-milling; the main effect of this procedure was to reduce the length of the fibres present in each sample. The numbers of fibres in unit masses, and the distribution of fibre sizes in all the samples, both parent and milled, were estimated from electron micrographs. The ability of all the samples to reduce the plating efficiency of V79-4 cells is compared, on the basis of mass, fibre number and fibre number number above various length thresholds. This biological activity of all the samples correlated best with the number of fibres above a threshold length of 6.5 micron. This is compared with the sizes of fibre previously reported to induce mesotheliomata when implanted into the pleural cavities of rats.
Asbestos and lung cancer: an analysis of the epidemiological evidence on the asbestos-smoking interaction. R. Saracci. 1977;20(3):323-31. PubMed · Publisher

Abstract

Three simple models for the asbestos-smoking interaction on human lung cancer production are considered. In the first model the excess incidence of lung cancer independently due to asbestos and to smoking adds together when both agents are present (additive model). In the second the addition of each one of the two agents produces an effect (increase in lung cancer incidence) which is proportional to the effect of the other (multiplicative model). In the third, asbestos can only increase lung cancer incidence in the presence of smoking. As previously found by other investigators, the additive model appears the least plausible in the light of the data from two published epidemiological studies. A discrimination between the other two models is attempted through a detailed analysis of the five published epidemiological studies today available which provide information on occupational asbestos exposure, smoking habits and lung cancer risk. Although the data do not allow a definitive discrimination, the multiplicative model appears to be more plausible, being also consistent with a multi-stage carcinogenic mechanism and with evidence from animal (rat) experiments. It is relevant both for biology and for public health that in this model asbestos and smoking are regarded as independently capable of producing lung cancer in humans and that they act synergistically when exposure to both occurs.
Assessment of cell-mediated immunity to malignant mesothelioma by microcytotoxicity tests. M.J. Embleton, J.C. Wagner, M.M. Wagner, et al. 1976;17(5):597-601. PubMed · Publisher

Abstract

Cell cultures were established from pleural effusions of patients with pleural mesothelioma, and peripheral mononuclear effector cells were tested for cytotoxicity against these cells by means of microcytotoxicity assay. Effector cells were obtained from normal healthy donors and from persons exposed occupationally to asbestos, including apparently healthy persons, patients with benign pleural conditions and patients with malignant mesothelioma. The overall incidence of cytotoxicity was low, and there was no evidence of increased cytotoxicity in mesothelioma patients or other asbestos-exposed donors. It is concluded that little or no tumour-directed cell-mediated immunity is detectable against malignant mesothelioma by microcytotoxicity methods.
Effect of age at inoculation of asbestos on occurrence of mesotheliomas in rats. G. Berry, J.C. Wagner. 1976;17(4):477-83. PubMed · Publisher

Abstract

An experiment in which rats were injected intrapleurally with asbestos, the injection taking place at an age of either 2 or 10 months, is reported. In the former group 19 out of 48 rats developed a mesothelioma compared with 17 out of 90 in the latter group. However, by considering the two groups at equal times after injection, eliminating the effects of natural mortality and also taking into account that not all of the mesotheliomas were the cause of death, it was shown that the incidence rate of mesotheliomas was significantly higher (p less than 0.01) in the rats injected at age 10 months and the relative rate was estimated as about 4, with 95% confidence limits of 1.5 and 12. An alternative explanation that the mesotheliomas occurred in the two groups at similar rates, except that in the group injected at age 10 months they occurred on average 4 months sooner after injection, is discussed. Two other groups were also injected, one at age 17 months and the other at 22 months. In the former group two early mesotheliomas were observed, 10 and 74 days after injection, but the next was not observed until over a year later. No explanation of this finding could be suggested other than the possibility that these two tumours were not associated with the asbestos treatment.
Epithelial outgrowths from lung tissue following intrapleural injection of asbestos dust in experimental animals. J.M. Davis. 1971;7(2):238-48. PubMed · Publisher

Abstract

After the intrapleural injection of asbestos dust in experimental animals, granulomas were produced and large areas of the pleural surface became thickened with fibrous tissue. In guinea-pigs injected with chrysotile dust, alveolar epithelial cells often migrated through the lung surface and were found lining spaces in the areas of pleural fibrosis. Initially these cells exhibited the exact structure of the surfactin-secreting type of alveolar cell, but later many of the cells lost the surfactin granules from their cytoplasm and became ciliated. In some animals cystic formation occurred in the lung tissue and groups of cysts grew out from the lung to invade the areas of pleural fibrosis. These cysts were also lined with surfactin-secreting alveolar cells. The possible association of these epithelial outgrowths and the well-known difficulties of diagnosing pleural mesotheliomas are discussed.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

1960s

UICC standard reference samples of asbestos. V. Timbrell, J.C. Gibson, I. Webster. 1968;3(3):406-8. PubMed · Publisher

Abstract

A la suite des recommandations faites en 1964 par le Groupe de travail " amiante et cancer " de l'UICC et dont l'application avait été examinée par un Comité spécial en 1965, des échantillons-étalons des cinq principaux types d'amiante ont été préparés par des chercheurs d'Afrique du Sud et du Royaume-Uni, avec l'aide des entreprises minières intéressées de divers pays.

Plusieurs laboratoires en étudient actuellement les propriétés physiques et chimiques. Les échantillons (en sachets de plastique de 500 g ou moins) peuvent être obtenus sur demande à la Pneumoconiosis Research Unit, Johannesburg, Afrique de Sud, ou à la P.R.U. de Penarth, Royaume-Uni.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.
The pathological effects of subcutaneous injections of asbestos fibres in mice: migration of fibres to submesothelial tissues and induction of mesotheliomata. F.J. Roe, R.L. Carter, M.A. Walters, et al. 1967;2(6):628-38. PubMed · Publisher

Abstract

Groups of 20 female CBA mice were injected subcutaneously in two sites with suspensions of crocidolite, amosite or chrysotile asbestos. Each injection consisted of 10 mg fibre suspended in 0.4 ml saline and each animal received 3 injections into each flank at sites well distant from the thorax. For comparison, two groups were similarly treated with crocidolite and amosite from which natural and contaminant oils had been removed by solvent extraction. The most remarkable feature of the results were, first, the apparently specific transport of asbestos fibres of all three types to the submesothelial tissues of the thorax and abdomen: and secondly, the development of extensive inflammatory and proliferative changes in these regions culminating, in 10 instances, in the formation of mesotheliomata. Six animals developed sarcomas at the injection site but, in most mice, there was little cellular response to asbestos in the subcutaneous tissues in contrast to the vigorous reactions seen in serosal membranes. All three types of asbestos induced both injection-site tumours and distant mesothelial changes and the removal of oils from amosite and crocidolite did not abolish—though it may have reduced—these manifestations of carcinogenic activity.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.
Tumour initiation by natural and contaminating asbestos oils. F.J. Roe, M.A. Walters, J.S. Harington. 1966;1(5):491-5. PubMed · Publisher

Abstract

Oils are present "naturally" in crocidolite and amosite asbestos. During processing, transport and storage, asbestos tends to be contaminated with other oils, including jute oil. Large commercial samples of crocidolite and amosite were extracted, by means of specially purified solvents, to remove both primary and contaminating oils. The latter were tested for tumour-initiating activity by twice-weekly application to the dorsal skin of mice alternating with once-weekly application of the tumour-promoting agent, croton oil. Significantly more papillomas and, in the case of amosite oil, carcinomas, arose in response to treatment with asbestos oil plus croton oil than in response to croton oil only. The tumour-initiating response was weak but reasons are given for not rejecting the possibility that the oils play a significant role in the induction of cancer by asbestos.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

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