Asbestos Exposure in Patients with Malignant Pleural Mesothelioma included in the PRIMATE Study, Lombardy, Italy

Our plain-English summary of Asbestos Exposure in Patients with Malignant Pleural Mesothelioma included in the PRIMATE Study, Lombardy, Italy, by A. Spinazzè, D. Consonni, F. Borghi, et al (International Journal of Environmental Research and Public Health, 2022).

The study

• Authors: A. Spinazzè, D. Consonni, F. Borghi, S. Rovelli, A. Cattaneo, C. Zellino, B. Dallari, A.C. Pesatori, H. Kromhout, S. Peters, L. Riboldi, D.M. Cavallo, C. Mensi
• Journal: International Journal of Environmental Research and Public Health
• Published: 2022;19(6)
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The PRIMATE study is an Italian translational research project, which aims to identify personalized biomarkers associated with clinical characteristics of malignant pleural mesothelioma (MPM). For this purpose, characteristics of MPM patients with different degrees of asbestos exposure will be compared to identify somatic mutations, germline polymorphism, and blood inflammatory biomarkers. In this framework, we assessed exposure to asbestos for 562 cases of MPM extracted from the Lombardy region Mesothelioma Registry (RML), for which a complete interview based on a standardized national questionnaire and histopathological specimens were available. Exposure assessment was performed: (1) through experts' evaluation (considered as the gold standard for the purpose of this study), according to the guidelines of the Italian National Mesothelioma Registry (ReNaM) and (2) using a job-exposure matrix (SYN-JEM) to obtain qualitative (ever/never) and quantitative estimates of occupational asbestos exposure (cumulative exposure expressed in fibers per mL (f/mL)). The performance of SYN-JEM was evaluated against the experts' evaluation. According to experts' evaluation, occupational asbestos exposure was recognized in 73.6% of men and 23.6% of women; furthermore, 29 men (7.8%) and 70 women (36.9%) had non-occupational exposure to asbestos. When applying SYN-JEM, 225 men (60.5%) and 25 women (13.2%) were classified as occupationally exposed, with a median cumulative exposure higher for men (1.7 f/mL-years) than for women (1.2 f/mL-years). The concordance between the two methods (Cohen's kappa) for occupational exposure assessment was 0.46 overall (0.41 in men, and 0.07 in women). Sensitivity was higher in men (0.73) than in women (0.18), while specificity was higher in women (0.88) than in men (0.74). Overall, both methods can be used to reconstruct past occupational exposure to asbestos, each with its own advantages and limitations.

In plain English

This study assessed asbestos exposure in 562 people (372 men, 190 women) with malignant pleural mesothelioma, selected from the Lombardy Mesothelioma Registry in Italy for 2000–2019 as part of the PRIMATE project. It compared evaluation by registry experts based on detailed interviews, treated as the reference, with a job-exposure matrix called SYN-JEM, which estimates exposure from job titles. The experts recognized occupational exposure in 73.6% of men and 23.6% of women. Para-occupational, home-related and environmental exposures were recognized more often in women. SYN-JEM classed 60.5% of men and 13.2% of women as occupationally exposed, with median cumulative exposures of 1.7 f/mL-years in men and 1.2 f/mL-years in women. Compared with the experts, SYN-JEM's sensitivity was 0.73 in men (95% CI 0.67 to 0.78) and 0.18 in women (0.09 to 0.32). Agreement (Cohen's kappa) was 0.46 overall (95% CI 0.39 to 0.53), 0.41 in men (0.34 to 0.48) and 0.07 in women (minus 0.01 to 0.15). The authors concluded that the methods were not completely consistent and that combining them gave the best possible estimate for their 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: Exposure-assessment study of registry mesothelioma cases, comparing a job-exposure matrix (SYN-JEM) against expert evaluation as the gold standard (occupational exposure only)
• Who was studied: 562 people with malignant pleural mesothelioma (372 men, 190 women), selected from more than 7000 cases in the Lombardy Mesothelioma Registry, Italy, 2000–2019. Selection required available tissue specimens at four PRIMATE hospitals and a complete interview. Mean age at diagnosis was about 69 years.
• Exposure: Lifetime asbestos exposure from job histories and non-occupational sources (para-occupational, home-related, environmental). Fiber types were not specified for the subjects. Exposed men worked mostly in metalworking and metallurgy, construction and asbestos-cement. Exposed women worked mostly in non-asbestos textile and clothing production, health and social services, and metalworking and metallurgy.
• Main results:
  • By expert evaluation, occupational exposure (definite, probable or possible) was recognized in 73.6% of men and 23.6% of women.
  • By expert evaluation, para-occupational, home-related and environmental exposures were recognized in 9.5%, 5.3% and 22.1% of women, and in 1.9%, 0.5% and 5.4% of men.
  • SYN-JEM classified 60.5% of men and 13.2% of women as occupationally exposed.
  • Among those SYN-JEM classed as exposed, median estimated cumulative exposure was 1.7 f/mL-years in men and 1.2 f/mL-years in women.
  • Against expert evaluation, SYN-JEM sensitivity was 0.65 overall (95% CI 0.60 to 0.70), 0.73 in men (0.67 to 0.78) and 0.18 in women (0.09 to 0.32). Specificity was 0.83 overall (0.77 to 0.87), 0.75 in men (0.65 to 0.82) and 0.88 in women (0.82 to 0.93).
  • Cohen's kappa agreement between methods was 0.46 overall (95% CI 0.39 to 0.53), 0.41 in men (0.34 to 0.48) and 0.07 in women (minus 0.01 to 0.15).
  • 111 subjects (74 men, 37 women) were occupationally exposed according to the experts but not according to SYN-JEM. 42 subjects (25 men, 17 women) showed the reverse pattern.
  • Among the 111 classed as exposed by experts only, 24 had worked in non-asbestos textile and cloth production using sewing or pressing machines. Others included bakers, hairdressers, office employees visiting production areas, and bystanders. 19 of the 111 (17%) had pleural plaques.
• The authors' conclusion: The authors concluded that the two methods were not completely consistent. In their view, combining retrospective exposure assessment techniques gave the best possible estimate for this study. They considered the expert method generally preferable in medico-legal settings and the JEM method most suitable for epidemiological studies.
• Limitations the authors state:
  • Expert evaluation relies on information that can be affected by recall, interviewer and assessor biases.
  • SYN-JEM may underestimate exposure through misclassification and errors in coding occupations. It cannot assess non-occupational exposure or variability between workers in the same job.
  • Cumulative occupational exposure could not be quantified for subjects classed as unexposed by SYN-JEM, and non-occupational exposures could not be quantified for anyone.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Pleural Mesothelioma, Biomarker, Somatic Mutation, Mesothelioma, Cumulative Exposure, Non-Occupational Exposure, Occupational Exposure.

Related studies

• Peritoneal mesothelioma and asbestos exposure: a population-based case-control study in Lombardy, Italy — D. Consonni, C. Calvi, et al. (2019)
• 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)
• 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)
• Differences between peritoneal and pleural mesothelioma in Lombardy, Italy — C. Mensi, M. Mendola, et al. (2017)

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