Effect of Asbestos Consumption on Malignant Pleural Mesothelioma in Italy: Forecasts of Mortality up to 2040

Our plain-English summary of Effect of Asbestos Consumption on Malignant Pleural Mesothelioma in Italy: Forecasts of Mortality up to 2040, by E. Oddone, J. Bollon, C.R. Nava, et al (Cancers, 2021).

The study

• Authors: E. Oddone, J. Bollon, C.R. Nava, D. Consonni, A. Marinaccio, C. Magnani, A. Gasparrini, F. Barone-Adesi
• Journal: Cancers
• Published: 2021;13(13)
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Statistical models used to forecast malignant pleural mesothelioma (MPM) trends often do not take into account historical asbestos consumption, possibly resulting in less accurate predictions of the future MPM death toll. We used the distributed lag non-linear model (DLNM) approach to predict future MPM cases in Italy until 2040, based on past asbestos consumption figures. Analyses were conducted using data on male MPM deaths (1970-2014) and annual asbestos consumption using data on domestic production, importation, and exportation. According to our model, the peak of MPM deaths is expected to occur in 2021 (1122 expected cases), with a subsequent decrease in mortality (344 MPM deaths in 2039). The exposure-response curve shows that relative risk (RR) of MPM increased almost linearly for lower levels of exposure but flattened at higher levels. The lag-specific RR grew until 30 years since exposure and decreased thereafter, suggesting that the most relevant contributions to the risk come from exposures which occurred 20-40 years before death. Our results show that the Italian MPM epidemic is approaching its peak and underline that the association between temporal trends of MPM and time since exposure to asbestos is not monotonic, suggesting a lesser role of remote exposures in the development of MPM than previously assumed.

In plain English

This study used national statistics to forecast deaths from malignant pleural mesothelioma (MPM) among men in Italy up to 2039. The authors linked yearly male MPM deaths from 1970 to 2014 with Italy's past national asbestos consumption, which they calculated from domestic production, imports and exports. They used a statistical method called a distributed lag non-linear model. Male MPM deaths rose from 152 to 960 per year over 1970–2014. The best-fitting model forecast a peak in 2021 of 1122 deaths (95% CI 1055–1193), falling to 344 (95% CI 317–373) in 2039. In the model, risk rose almost linearly at lower consumption levels but flattened at higher levels. Risk was greatest for exposure about 30 years before death, and exposures 20–40 years earlier contributed most. Changing the model's assumptions did not change the forecasts substantially. The authors concluded that the Italian epidemic is approaching its peak and that remote exposures may play a lesser role than previously assumed. They noted that the forecasts cover men only and that national consumption figures cannot reflect fiber type, jobs or preventive measures.

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-level time-series modelling and forecasting study: a quasi-Poisson model with a distributed lag non-linear model (DLNM) linking past national asbestos consumption to male MPM deaths, fitted to 1970–2014 data and used to forecast 2015–2039
• Who was studied: Male deaths from malignant pleural mesothelioma in Italy, 1970–2014, from the Italian National Statistical Institute (ISTAT); annual deaths rose from 152 to 960 over the period. Deaths before 2003 were estimated from pleural cancer deaths using a correction factor.
• Exposure: Annual national per capita asbestos consumption in Italy (from domestic production, importation and exportation), 1946–1992, peaking at nearly 6 tons per 100,000 inhabitants in the late 1970s; fiber types not specified. Assumptions were tested for exposure before 1946, post-1992 exposure (5% to 30% of 1992 levels) and exposure age ranges.
• Main results:
  • Male MPM deaths in Italy rose from 152 to 960 per year over 1970–2014.
  • The best-performing model assumed asbestos exposure between ages 20 and 70 and post-ban exposure equal to 10% of the 1992 level.
  • Forecast peak of male MPM deaths in Italy in 2021: 1122 expected cases (95% CI 1055–1193).
  • Forecast decline to 344 (95% CI 317–373) male MPM deaths in 2039, about 30% of the peak.
  • At a lag of 20 years, the relative risk of MPM increased almost linearly at lower exposure levels but flattened at higher levels.
  • For an annual exposure of 4.2 tons per 100,000 inhabitants, the lag-specific relative risk grew until 30 years after exposure and decreased thereafter. Exposures 20–40 years before death contributed most to risk.
  • Forecasts did not change substantially when the basic assumptions were changed in sensitivity analyses.
• The authors' conclusion: The authors concluded that the MPM epidemic among men in Italy is approaching its peak and that the relationship between MPM trends and time since asbestos exposure is not monotonic, suggesting a lesser role of remote exposures than previously assumed.
• Limitations the authors state:
  • Forecasts were based only on male MPM mortality and may not apply to women, whose circumstances of exposure differ.
  • National consumption figures were used as a proxy for exposure. They cannot account for the number of exposed workers, fiber types, industries and jobs, or preventive measures.
  • Asbestos consumption before 1946 was assumed equal to the 1946 level, although an increasing trend before then is plausible.
  • Improvements in diagnosis and treatment could reduce future mortality and change the forecasts.
  • Asbestos use data could not be reliably analyzed at the regional level, although use and disease are not uniform across Italy.
  • National mortality data on pleural cancer deaths have been reported to underestimate the true number of mesotheliomas.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Relative Risk.

Related studies

• Forecast of Malignant Peritoneal Mesothelioma Mortality in Italy up to 2040 — E. Oddone, J. Bollon, et al. (2020)
• Predictions of Mortality from Pleural Mesothelioma in Italy After the Ban of Asbestos Use — E. Oddone, J. Bollon, et al. (2020)
• Predictions of mortality from pleural mesothelioma in Italy: a model based on asbestos consumption figures supports results from age-period-cohort models — A. Marinaccio, F. Montanaro, et al. (2005)
• Cumulative asbestos exposure and mortality from asbestos related diseases in a pooled analysis of 21 asbestos cement cohorts in Italy — F. Luberto, D. Ferrante, et al. (2019)
• Asbestos Consumption and Malignant Mesothelioma Mortality Trends in the Major User Countries — C. Gariazzo, A. Gasparrini, et al. (2023)
• Burden of Mortality from Asbestos-Related Diseases in Italy — L. Fazzo, A. Binazzi, et al. (2021)

Browse more research in Cancers, or return to medical research.