Pulmonary carcinoid tumors and asbestos exposure

Our plain-English summary of Pulmonary carcinoid tumors and asbestos exposure, by B. Clin, P. Andujar, I. Abd Al Samad, et al (The Annals of Occupational Hygiene, 2012).

The study

• Authors: B. Clin, P. Andujar, I. Abd Al Samad, C. Azpitarte, F. Le Pimpec-Barthes, M.A. Billon-Galland, C. Danel, F. Galateau-Salle, B. Housset, K. Legrand-Cattan, M. Matrat, I. Monnet, M. Riquet, J.C. Pairon
• Journal: The Annals of Occupational Hygiene
• Published: 2012;56(7):789-95
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objectives: The hypothesis that asbestos exposure may have more specific associations with particular histological types of lung cancer remains controversial. The aim of this study was to analyze the relationships between asbestos exposure and pulmonary carcinoid tumors.

Methods: A retrospective case-control study was conducted in 28 cases undergoing surgery for pulmonary carcinoid tumors and aged >40 years and in 56 controls with lung cancer of a different histological type, matched for gender and age, from 1994 to 1999, recruited in two hospitals in the region of Paris. Asbestos exposure was assessed via expertise of a standardized occupational questionnaire and mineralogical analysis of lung tissue, with quantification of asbestos bodies (AB).

Results: Definite asbestos exposure was identified in 25% of cases and 14% of controls (ns). Cumulative asbestos exposure was significantly higher in cases than in controls (P < 0.05), and results of the quantification of AB tended to be higher in cases than in controls (24 and 9% had >1000 AB per gram dry lung tissue, respectively, P = 0.09). Mean cumulative smoking was lower in cases than in controls (P < 0.05).

Conclusions: This study argues in favor of a relationship between asbestos exposure and certain pulmonary carcinoid tumors.

In plain English

This retrospective case-control study in two Paris-region hospitals examined whether occupational asbestos exposure was linked to pulmonary carcinoid tumors, a rare lung tumor. Of 34 carcinoid patients operated on from 1994 to 1999, the 28 aged over 40 were compared with 56 other lung cancer patients matched for gender and age. An occupational-disease specialist judged exposure from a work-history questionnaire; asbestos bodies in lung tissue were also counted. Definite exposure was found in 25% of cases and 14.3% of controls (not statistically significant). Among exposed subjects, the cumulative exposure index was higher in cases than controls (means 3.5 and 0.3, p less than 0.05). More than 1000 asbestos bodies per gram of dry lung were found in 23.8% of tested cases and 8.9% of controls (p = 0.09). Cases had lower mean cumulative smoking (28.2 versus 43.2 pack years, p less than 0.05), but smoking status did not differ significantly. The authors concluded the study argues in favor of a relationship between asbestos exposure and certain pulmonary carcinoid tumors. They noted the small number of cases and that controls also had lung cancer.

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.

What the study did and found

• Design: retrospective case-control study
• Who was studied: 34 patients who had surgery for pulmonary carcinoid tumors (25 typical, 9 atypical). The main comparison used the 28 cases aged over 40 and 56 controls aged over 40 who had surgery for other types of lung cancer (30 adenocarcinomas, 13 epidermoid carcinomas, 9 large cell carcinomas, 4 other or mixed). Controls were matched for gender and age within 3 years. Subjects were recruited in two hospitals in the Paris region, France, from 1994 to 1999.
• Exposure: Occupational asbestos exposure (fiber types not specified). It was assessed by an occupational-disease specialist, who did not know case or control status, from a standardized job-history questionnaire. The specialist rated the probability, frequency and intensity of exposure and combined them into a cumulative exposure index. Exposure was also measured by counting asbestos bodies in tumor-free dry lung tissue, with more than 1000 asbestos bodies per gram of dry lung taken as significant retention.
• Main results:
  • Definite asbestos exposure was found in 25% of cases aged over 40 (7 of 28) and 14.3% of controls (8 of 56). The difference was not statistically significant.
  • Among exposed subjects, the cumulative exposure index was higher in cases aged over 40 than in controls, with p less than 0.05. The mean was 3.5 (SD 4.5) in cases and 0.3 (SD 0.5) in controls; the medians were 2.28 and 0.22.
  • More than 1000 asbestos bodies per gram of dry lung tissue were found in 5 cases (23.8% of the cases with lung tissue analysis; analysis was not available in seven cases because of insufficient material) and in 5 of 56 controls (8.9%), p = 0.09. The authors described this as tending to be higher in cases.
  • Mean cumulative smoking was lower in cases aged over 40 (28.2 pack years, SD 30.5) than in controls (43.2 pack years, SD 21.1), with p less than 0.05.
  • Smoking status did not differ significantly between the groups. Non-smokers made up 9 of 28 cases aged over 40 (32.1%) and 8 of 56 controls (14.3%).
  • Among all 34 cases, 25 (74%) had a typical carcinoid tumor and 9 had an atypical carcinoid tumor. No significant difference was seen between the two groups in age, gender, tobacco consumption or cumulative asbestos exposure.
  • In subjects with confirmed asbestos exposure, the mean time since the start of exposure was 44 years (SD 6.16) for cases and 48 years (SD 6.63) for controls.
• The authors' conclusion: The authors concluded that their results argue in favor of a relationship between occupational asbestos exposure and certain pulmonary carcinoid tumors. They called for further research using controls free of lung cancer to confirm the observed trends.
• Limitations the authors state:
  • The number of cases was low, which reduced statistical power, because pulmonary carcinoid tumors are rare. Cases were consecutive surgical patients from two hospitals who lived in the Paris region.
  • The controls had lung cancer of other types, which may itself be asbestos-related, so the choice of controls is open to debate. The authors considered this bias conservative.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Lung Cancer, Case-Control Study, Asbestos Bodies.

Related studies

• The use of immunohistochemistry in the diagnosis of composite and collision tumors: exemplified by pleural mesothelioma and carcinoid tumor of the lung — N.G. Ordóñez (2012)
• Distinct keratin patterns demonstrated by immunoperoxidase staining of adenocarcinomas, carcinoids, and mesotheliomas using polyclonal and monoclonal anti-keratin antibodies — H.J. Kahn, P.S. Thorner, et al. (1986)
• Atypical carcinoid presenting as mesothelioma — P. van Hengel, F. van Geffen, et al. (2001)
• p40 is the best marker for diagnosing pulmonary squamous cell carcinoma: comparison with p63, cytokeratin 5/6, desmocollin-3, and sox2 — T. Tatsumori, K. Tsuta, et al. (2014)
• p16INK4A inactivation mechanisms in non-small-cell lung cancer patients occupationally exposed to asbestos — P. Andujar, J. Wang, et al. (2010)
• Differential mutation profiles and similar intronic TP53 polymorphisms in asbestos-related lung cancer and pleural mesothelioma — P. Andujar, J.C. Pairon, et al. (2013)

Browse more research in The Annals of Occupational Hygiene, or return to medical research.