Serum PDGF-AB in pleural mesothelioma

Our plain-English summary of Serum PDGF-AB in pleural mesothelioma, by R. Filiberti, P. Marroni, M. Neri, et al (Tumour Biology, 2005).

The study

• Authors: R. Filiberti, P. Marroni, M. Neri, A. Ardizzoni, P.G. Betta, M.A. Cafferata, P.A. Canessa, R. Puntoni, G.P. Ivaldi, M. Paganuzzi
• Journal: Tumour Biology
• Published: 2005;26(5):221-6
• Cited by: 31 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Overexpression of platelet-derived growth factor (PDGF) has been observed in lung and pleural tumors. The aim of this study was to evaluate the diagnostic and prognostic role of serum PDGF in pleural mesothelioma (PM). Four groups of subjects were studied: 93 malignant PM patients, 33 primary non small cell lung cancer patients, 51 subjects exposed to asbestos, defined as high-risk controls, and 24 healthy controls. PDGF-AB mean concentration was higher in PM patients (45.8 ng/ml) than in high-risk controls (33.1 ng/ml) and healthy controls (26.8 ng/ml). Using the cut-off level of 49.8 ng/ml, corresponding to the mean+2SD of PDGF-AB in healthy controls, 43% of PM patients showed positive PDGF-AB levels. Survival was evaluated in 82 PM patients. At the end of the follow-up (median 9.8 months) 80.5% of patients had died. Median survival was 13.1 and 7.9 months for patients with PDGF-AB lower and higher than the cut-off, respectively. Adjusting for age, sex, histology and platelet count, positive PDGF-AB levels were associated with lower survival (OR=1.2, 95%CI: 0.9-1.6), even if not significantly so. In conclusion, serum PDGF may represent a useful additional parameter to prognostic factors already available for PM.

Copyright (c) 2005 S. Karger AG, Basel.

In plain English

This Italian study tested whether a blood protein, platelet-derived growth factor AB (PDGF-AB), could help diagnose pleural mesothelioma or predict survival. Between 1996 and 2000 the authors enrolled 93 pleural mesothelioma patients, 33 non-small cell lung cancer patients, 51 former asbestos factory or shipyard workers (high-risk controls) and 24 healthy controls, and measured PDGF-AB in their stored serum. The average level was 45.8 ng/ml in mesothelioma patients. That was significantly higher than in high-risk controls (33.1) and healthy controls (26.8), but not significantly different from lung cancer patients. Using a cut-off of 49.8 ng/ml, 40 of 93 mesothelioma patients (43.0%) were positive. The authors judged this of poor clinical use for diagnosis. In 82 mesothelioma patients followed up, median survival was 13.1 months below the cut-off and 7.9 months above it. After adjustment for age, sex, histology and platelet count, the association (OR = 1.2; 95% CI 0.9 to 1.6) was not statistically significant. The authors concluded high levels may be associated with shorter survival, which needs confirmation in a larger study.

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: Comparison of serum PDGF-AB levels across four groups (mesothelioma patients, lung cancer patients, asbestos-exposed high-risk controls, healthy controls), plus survival analysis (Kaplan-Meier and Cox regression) in mesothelioma patients
• Who was studied: 201 subjects enrolled from March 1996 to August 2000 in Genova, Casale and La Spezia, Northern Italy. They were 93 pleural mesothelioma patients, 33 non-small cell lung cancer patients, 51 asbestos-exposed high-risk controls and 24 healthy controls (blood donors and patients hospitalized for trauma or eye diseases). Serum was stored at minus 80 degrees C until assayed. Survival was analysed in 82 mesothelioma patients with a recorded platelet count and follow-up data.
• Exposure: The high-risk controls had previously worked in an asbestos factory or a shipyard. Most (80%) had benign lung diseases: 36 had asbestosis or silicosis and 5 had chronic obstructive pulmonary disease. No fiber types or doses were reported. In Table 1, 66 of the 93 mesothelioma patients (71.0%) were recorded as asbestos-exposed. The measured variable was serum PDGF-AB.
• Main results:
  • Mean serum PDGF-AB was 45.8 ng/ml in mesothelioma patients. This was significantly higher than in high-risk controls (33.1 ng/ml, p = 0.004) and healthy controls (26.8 ng/ml). It was not significantly different from lung cancer patients (p = 0.2).
  • No significant correlation was found between PDGF-AB levels and sex, age, occupational category, asbestos exposure or smoking habits.
  • Using a cut-off of 49.8 ng/ml (mean plus 2 SD in healthy controls), levels were positive in 40 of 93 mesothelioma patients (43.0%), 10 of 33 lung cancer patients (30.3%) and 9 of 51 high-risk controls (17.6%).
  • For diagnosis, sensitivity was 43% and specificity was 82.4% against high-risk controls, which the authors called of poor clinical utility. So far, none of the nine high-risk controls with raised PDGF had developed mesothelioma.
  • Only 16 of the 38 mesothelioma patients with positive PDGF-AB levels (among 83 with platelet counts) had thrombocytosis (a high platelet count).
  • In 82 mesothelioma patients (median follow-up 9.8 months), 66 (80.5%) died. Median survival was 13.1 months for patients below the cut-off and 7.9 months for those above it (p = 0.02).
  • In the multivariate analysis (adjusted for age, sex, histology and platelet count), positive PDGF-AB levels in mesothelioma patients gave OR = 1.2 (95% CI 0.9 to 1.6, p = 0.06). This was not statistically significant.
• The authors' conclusion: The authors concluded that, although not statistically significant in multivariate analysis, their data suggested PDGF-AB levels above the cut-off may be associated with shorter survival in pleural mesothelioma. They said this trend requires confirmation from a larger study and may complement existing prognostic factors.
• Limitations the authors state:
  • PDGF was measured in serum rather than plasma. Platelets release PDGF during clotting, so raised levels could partly reflect thrombocytosis.
  • The survival trend did not reach statistical significance and needs confirmation from a larger study.

Topics

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

Medical terms in this study, explained in our Lexicon: Platelet-Derived Growth Factor (PDGF), Pleural Mesothelioma, Small Cell Lung Cancer, Median Survival, Histology.

Related studies

• Rapid activation of PDGF-A and -B expression at sites of lung injury in asbestos-exposed rats — J.Y. Liu, G.F. Morris, et al. (1997)
• Chrysotile asbestos upregulates gene expression and production of alpha-receptors for platelet-derived growth factor (PDGF-AA) on rat lung fibroblasts — J.C. Bonner, A.L. Goodell, et al. (1993)
• Human ovarian tumors of epithelial origin express PDGF in vitro and in vivo — M.A. Versnel, M. Haarbrink, et al. (1994)
• Relationship of fiber surface iron and active oxygen species to expression of procollagen, PDGF-A, and TGF-beta(1) in tracheal explants exposed to amosite asbestos — J. Dai, A. Churg (2001)
• PDGF-D/PDGF-ββ receptor-regulated chemotaxis of malignant mesothelioma cells — A. Okada, T. Yaguchi, et al. (2012)
• Asbestos-induced alveolar injury. Evidence for macrophage-derived PDGF as a mediator of the fibrogenic response — J.C. Bonner, A.R. Brody (1991)

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