Asbestos exposure, pleural plaques and digestive cancers

Our plain-English summary of Asbestos exposure, pleural plaques and digestive cancers, by B. Clin, C. Gramond, F. Delva, et al (BMC Public Health, 2025).

The study

• Authors: B. Clin, C. Gramond, F. Delva, P. Andujar, I. Thaon, P. Brochard, J. Benoist, A. Gislard, F. Laurent, I. Benlala, C. Paris, J.C. Pairon
• Journal: BMC Public Health
• Published: 2025;25(1):686
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: The aim of this study was to analyse the incidence and mortality from various digestive cancer sites and their potential link with pleural plaques, in a French cohort of workers previously occupationally exposed to asbestos.

Methods: We conducted a 10-year follow-up study in 13,481 male subjects, included in the cohort between October 2003 and December 2005, for whom asbestos exposure was assessed by calculation of a cumulative exposure index (CEI) in equivalent fibres.years/mL for each subject. We conducted an incidence study and a mortality study. Complementary analysis was restricted to men who had performed at least one chest CT-scan (N = 4,794). We used a Cox model with age as the time axis variable, adjusted for smoking, time since first exposure (TSFE), CEI to asbestos and the existence of pleural plaques on CT-scan.

Results: In the incidence study, a significant dose-response relationship was observed between CEI to asbestos and oesophageal cancer (HR 1.03, 95% CI [1.01-1.06]) in the entire cohort after adjustment for TSFE and smoking status. In subjects undergoing CT-scan, a significant association between pleural plaques was observed for oesophageal cancer incidence (HR 2.80, 95% CI [1.09-7.20]) and in the mortality study, multivariate analyses showed a significant dose-effect response between CEI to asbestos and death from oesophageal cancer (HR 1.03, 95% CI [1.00-1.05]) in the entire cohort.

Conclusions: This large-scale study confirms results concerning a likely relationship between asbestos exposure and oesophageal cancer, and the association between this cancer and pleural plaques after adjustment on CEI to asbestos.

© 2025. The Author(s).

In plain English

This French cohort study followed men formerly exposed to asbestos at work who joined a screening programme (the ARDCO cohort). Industrial hygienists estimated each man's cumulative exposure in equivalent fibres.years/mL. Fiber types for these men are not given. Among 12,725 men followed to 1 July 2021, 685 digestive cancers were recorded, 47 oesophageal. Higher cumulative exposure was associated with oesophageal cancer incidence (hazard ratio 1.03, 95% CI 1.01–1.06, per 10 fibres.years/mL) and with death from oesophageal cancer (HR 1.03, 95% CI 1.00–1.05). No statistically significant dose-response was found for digestive cancers overall or for colon or rectal, stomach, liver or pancreatic cancer. Among 4,794 men with chest CT scans, those with pleural plaques had a higher incidence of oesophageal cancer (HR 2.80, 95% CI 1.09–7.20) after adjustment for exposure and smoking. Plaques showed no statistically significant association with death from digestive cancer (HR 1.08, 95% CI 0.66–1.75). The authors concluded the study confirms a likely relationship between asbestos exposure and oesophageal cancer. They noted lacking alcohol data and detailed smoking data, and that only men were analysed.

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: Cohort follow-up study with separate incidence and mortality analyses, using Cox proportional hazards models; a complementary analysis was done in the subgroup with chest CT scans
• Who was studied: Men in the Asbestos-Related Diseases Cohort (ARDCO), made up of retired or unemployed workers formerly occupationally exposed to asbestos in four French regions (Aquitaine, Upper Normandy, Lower Normandy, Rhône-Alpes). Of 13,481 men, 12,725 were included in the incidence analysis and 12,519 in the mortality analysis. A 'CT-scan sample' of 4,794 men had at least one readable chest CT scan. Women (737) were excluded from the analysis.
• Exposure: Occupational asbestos exposure. The article does not specify the fiber types to which this cohort was exposed. Industrial hygienists assessed exposure from a standardised job-history questionnaire and expressed it as a cumulative exposure index (CEI) in equivalent fibres.years/mL. Mean CEI was 60.2 and mean exposure duration 31.3 years in the incidence population. Pleural plaques were assessed on CT scans read by expert radiologists.
• Main results:
  • Among the 12,725 men in the incidence analysis, 685 digestive cancers were recorded up to 1 July 2021.
  • Of these digestive cancers, 47 were oesophageal in the entire cohort and 19 in the CT-scan population.
  • Entire cohort: no dose-response was found between cumulative exposure and all digestive cancers combined (HR 1.00, 95% CI 0.99–1.01 per 10 f.years/mL).
  • Entire cohort: cumulative exposure was associated with oesophageal cancer incidence (HR 1.03, 95% CI 1.01–1.06 per 10 f.years/mL) after adjustment for time since first exposure and smoking.
  • Entire cohort: no dose-response was found for colon or rectal cancer (HR 1.00, 95% CI 0.99–1.01 per 10 f.years/mL).
  • Entire cohort: no dose-response was found for stomach cancer (HR 0.98, 95% CI 0.95–1.01) or liver cancer (HR 0.99, 95% CI 0.97–1.02).
  • Entire cohort: no dose-response was found for pancreatic cancer (HR 1.00, 95% CI 0.98–1.03 per 10 f.years/mL).
  • CT-scan sample: pleural plaques were not significantly associated with incidence of all digestive cancers combined (HR 0.83, 95% CI 0.61–1.12).
  • CT-scan sample: pleural plaques were associated with oesophageal cancer incidence (HR 2.80, 95% CI 1.09–7.20) after adjustment for asbestos exposure and smoking.
  • CT-scan sample: 10 oesophageal cancers occurred among 1,174 men with pleural plaques, and 9 among 3,393 men without (Table 4).
  • Mortality, entire cohort: no significant dose-response was found between cumulative exposure and death from all digestive cancers (HR 1.00, 95% CI 0.99–1.02 per 10 f.years/mL).
  • Mortality, entire cohort: cumulative exposure was associated with death from oesophageal cancer (HR 1.03, 95% CI 1.00–1.05 per 10 f.years/mL) in both univariate and multivariate analyses.
  • Mortality, CT-scan sample: no statistically significant association was observed between pleural plaques and death from digestive cancer (HR 1.08, 95% CI 0.66–1.75).
• The authors' conclusion: The authors concluded that the study confirms results concerning a likely relationship between asbestos exposure and oesophageal cancer, and an association between this cancer and pleural plaques after adjustment for cumulative exposure. They called for studies with greater statistical power to confirm the observed trends.
• Limitations the authors state:
  • Only men were analysed, because the 737 women (39 with digestive cancer) did not give sufficient statistical power.
  • Smoking was adjusted for only in broad categories (never, former, current), with no pack-years data.
  • Alcohol consumption, a potential confounding factor, could not be taken into account.
  • Smoking information was missing for 31% of subjects; the authors used multiple imputation to fill the gaps.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening, Throat and laryngeal cancer.

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Pleural Plaques, Cumulative Exposure, Dose-response relationship, Esophageal Cancer.

Related studies

• Relationships between asbestos exposure and pleural plaques: dose and time effects using fractional polynomials — M. Menant, I. Benlala, et al. (2024)
• Digestive cancers and occupational asbestos exposure: incidence study in a cohort of asbestos plant workers — M. Boulanger, F. Morlais, et al. (2015)
• Asbestos exposure, pleural plaques, and the risk of death from lung cancer — J.C. Pairon, P. Andujar, et al. (2014)
• Occupational asbestos exposure and digestive cancers - a cohort study — B. Clin, F. Morlais, et al. (2009)
• Cancer of the esophagus and asbestos exposure — B. Clin, I. Thaon, et al. (2017)
• Incidence of digestive cancers and occupational exposure to asbestos — S. de La Provôté, N. Desoubeaux, et al. (2002)

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