Peritoneal mesothelioma and asbestos exposure: a population-based case-control study in Lombardy, Italy

Our plain-English summary of Peritoneal mesothelioma and asbestos exposure: a population-based case-control study in Lombardy, Italy, by D. Consonni, C. Calvi, S. De Matteis, et al (Occupational and Environmental Medicine, 2019).

The study

• Authors: D. Consonni, C. Calvi, S. De Matteis, D. Mirabelli, M.T. Landi, N.E. Caporaso, S. Peters, R. Vermeulen, H. Kromhout, B. Dallari, A.C. Pesatori, L. Riboldi, C. Mensi
• Journal: Occupational and Environmental Medicine
• Published: 2019;76(8):545-553
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objectives: Asbestos is the main risk factor for peritoneal mesothelioma (PeM). However, due to its rarity, PeM has rarely been investigated in community-based studies. We examined the association between asbestos exposure and PeM risk in a general population in Lombardy, Italy.

Methods: From the regional mesothelioma registry, we selected PeM cases diagnosed in 2000-2015. Population controls (matched by area, gender and age) came from two case-control studies in Lombardy on lung cancer (2002-2004) and pleural mesothelioma (2014). Assessment of exposure to asbestos was performed through a quantitative job-exposure matrix (SYN-JEM) and expert evaluation based on a standardised questionnaire. We calculated period-specific and gender-specific OR and 90% CI using conditional logistic regression adjusted for age, province of residence and education.

Results: We selected 68 cases and 2116 controls (2000-2007) and 159 cases and 205 controls (2008-2015). The ORs for ever asbestos exposure (expert-based, 2008-2015 only) were 5.78 (90% CI 3.03 to 11.0) in men and 8.00 (2.56 to 25.0) in women; the ORs for definite occupational exposure were 12.3 (5.62 to 26.7) in men and 14.3 (3.16 to 65.0) in women. The ORs for ever versus never occupational asbestos exposure based on SYN-JEM (both periods) were 2.05 (90% CI 1.39 to 3.01) in men and 1.62 (0.79 to 3.27) in women. In men, clear positive associations were found for duration, cumulative exposure (OR 1.33 (1.19 to 1.48) per fibres/mL-years) and latency.

Conclusions: Using two different methods of exposure assessment we provided evidence of a clear association between asbestos exposure and PeM risk in the general population.

© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

In plain English

This population-based case–control study in Lombardy, Italy, compared people with peritoneal mesothelioma (cancer of the abdominal lining) from the regional registry with general-population controls. The analysis included 68 cases and 2116 controls for 2000–2007, and 159 cases and 205 controls for 2008–2015. Experts assessed asbestos exposure from a detailed questionnaire (2008–2015 only), and a job-exposure matrix (SYN-JEM) assessed it from job titles. With expert assessment, the odds ratio for ever exposure was 5.78 (90% CI 3.03 to 11.0) in men and 8.00 (2.56 to 25.0) in women. For definite occupational exposure, the odds ratios were 12.3 (5.62 to 26.7) in men and 14.3 (3.16 to 65.0) in women. With SYN-JEM, across both periods, the odds ratio for ever versus never occupational exposure was 2.05 (90% CI 1.39 to 3.01) in men and 1.62 (0.79 to 3.27) in women. In men, odds ratios rose with cumulative exposure and time since first exposure. The authors concluded there were clear associations among men. They noted that expert assessment of cases was unblinded and that chrysotile and amphibole exposure could not be separated.

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: Population-based case–control study (cases from a regional mesothelioma registry; controls from two earlier population-based case–control studies)
• Who was studied: Peritoneal mesothelioma cases from the Lombardy Mesothelioma Registry, Italy. For 2000–2007: 68 cases (41 men, 27 women) and 2116 EAGLE controls (sampled 2002–2004). For 2008–2015: 159 cases (86 men, 73 women) and 205 MISEM controls (sampled 2014).
• Exposure: Lifetime asbestos exposure, mainly occupational. It was assessed by expert evaluation of a standardised national mesothelioma registry (ReNaM) questionnaire for 2008–2015, and by a quantitative job-exposure matrix (SYN-JEM) giving cumulative exposure in fibres/mL-years for both periods. Chrysotile and amphiboles were used together in Italy, so fiber types could not be distinguished.
• Main results:
  • Expert-based assessment, 2008–2015: ever asbestos exposure in men, OR 5.78 (90% CI 3.03 to 11.0), with 64 of 86 male cases (74.4%) exposed.
  • Expert-based assessment, 2008–2015: ever asbestos exposure in women, OR 8.00 (90% CI 2.56 to 25.0), with 26 (36.6%) female cases exposed.
  • Expert-based assessment: definite occupational exposure, OR 12.3 (90% CI 5.62 to 26.7) in men and 14.3 (3.16 to 65.0) in women.
  • SYN-JEM, both periods combined: ever versus never occupational exposure in men, OR 2.05 (90% CI 1.39 to 3.01), with 72 of 127 male cases (56.7%) exposed.
  • SYN-JEM, women: 17 of 100 cases (17.0%) exposed, OR 1.62 (90% CI 0.79 to 3.27), with no clear patterns by duration, cumulative exposure or latency.
  • In men, the odds ratio rose with cumulative exposure: OR 1.33 (90% CI 1.19 to 1.48) per fibres/mL-year.
  • In men (SYN-JEM), the odds ratio kept increasing with time since first exposure, reaching 4.99 (90% CI 2.26 to 11.1) at 60 or more years.
• The authors' conclusion: The authors concluded that, among men, there were clear associations between peritoneal mesothelioma risk and several measures of asbestos exposure (probability, duration and cumulative exposure), consistent across both assessment methods. In women, clearly increased risks were found only with the expert questionnaire-based assessment, which the authors attributed most likely to women's low prevalence of asbestos exposure.
• Limitations the authors state:
  • Controls were recruited only in limited time periods (2002–2004 and 2014), and the EAGLE controls did not cover the whole population of the five provinces.
  • EAGLE controls were interviewed with a different questionnaire from the one used for cases and MISEM controls.
  • Participation among MISEM controls was low (48.1%), which could have under-represented blue collar workers.
  • Chrysotile and amphiboles were used together in Italy, so exposure to the two types could not be distinguished.
  • Expert assessment of cases was not blinded, so recall, interviewer and assessor biases could have pushed the expert-based odds ratios upward.
  • The job-exposure matrix may underestimate odds ratios because of exposure misclassification and possible errors in coding occupations.

Topics

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

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Asbestos Exposure, Case-Control Study, Mesothelioma, Lung Cancer, Pleural Mesothelioma, Occupational Exposure, Cumulative Exposure.

Related studies

• Differences between peritoneal and pleural mesothelioma in Lombardy, Italy — C. Mensi, M. Mendola, et al. (2017)
• Asbestos Exposure in Patients with Malignant Pleural Mesothelioma included in the PRIMATE Study, Lombardy, Italy — A. Spinazzè, D. Consonni, et al. (2022)
• Gender differences in pleural mesothelioma occurrence in Lombardy and Piedmont, Italy — D. Consonni, E. Migliore, et al. (2019)
• Incidence of mesothelioma in Lombardy, Italy: exposure to asbestos, time patterns and future projections — C. Mensi, S. De Matteis, et al. (2016)
• Estimate of environmental and occupational components in the spatial distribution of malignant mesothelioma incidence in Lombardy (Italy) — D. Catelan, D. Consonni, et al. (2020)
• Mesothelioma in Agriculture in Lombardy, Italy: An Unrecognized Risk — C. Mensi, B. Dallari, et al. (2021)

Browse more research in Occupational and Environmental Medicine, or return to medical research.