Future trends of mesothelioma mortality in Japan based on a risk function

Our plain-English summary of Future trends of mesothelioma mortality in Japan based on a risk function, by T. Myojin, K. Azuma, J. Okumura, et al (Industrial Health, 2012).

The study

• Authors: T. Myojin, K. Azuma, J. Okumura, I. Uchiyama
• Journal: Industrial Health
• Published: 2012;50(3):197-204
• Cited by: 24 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Mesothelioma is a malignancy with poor prognosis. It is chiefly caused by asbestos exposure and its symptoms can occur about 30-50 yr after the initial exposure. This study aims to predict the future trends in mesothelioma mortality in Japan using a method that is an alternative to the age-cohort model. Our approach is based on a risk function that links mesothelioma mortality combined with data pertaining to the population, size of the labor force, and quantity of asbestos imports. We projected the number of deaths occurring in individuals aged 50-89 for yr 2003-2050 using risk functions. Our results have indicated that mesothelioma mortality among Japanese people aged 50-89 yr will continue to increase until 2027 and reach a maximum of 66,327 deaths in the years 2003-2050. Our estimate has also suggested that the number of mesothelioma deaths could be significantly reduced if there were adequate compliance with the administrative level guidelines for occupational asbestos exposure.

In plain English

This modeling study projected future mesothelioma deaths in Japan by adapting a French risk-function model. Occupational exposure was estimated from manufacturing and construction labor force size and yearly asbestos imports since 1949. The model was fitted to 80% of actual deaths in 2003 to 2009, the share attributed to work exposure. Across eight scenarios, projected work-related deaths for ages 50 to 74 in 2003 to 2050 ranged from 11,827 to 17,443; seven scenarios peaked in 2015 or 2016, one in 2010. For ages 50 to 89 the range was 15,948 to 53,062, though the model fitted poorly for people in their 80s. Multiplying by 1.25 to cover all exposures gave 19,935 to 66,327 deaths. Under a scenario of workplace compliance with exposure limits, projected totals were 4,394 to 23,463. The authors wrote that more than 60% of deaths would be avoided under compliance, concluding it could significantly reduce deaths. They noted that reliable death data covered only a few years and that fiber types were not recorded. They also noted that exposure from demolition and disposal of building materials, which affected workers and the public, was not included.

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: Mathematical projection (modeling) study using a risk function adapted from the Banaei model for French men, fitted to recent national mesothelioma death counts
• Who was studied: Japanese people (males and females) aged 50 to 74 in the main model, extended to ages 50 to 89. The model was fitted to actual mesothelioma deaths from 2003 to 2009 and used to project deaths for 2003 to 2050. Ages at first and last exposure came from 221 mesothelioma patients in 27 hospitals (2000 to 2008).
• Exposure: Occupational asbestos exposure, estimated by multiplying the labor force in manufacturing and construction, by age, by the relative amount of asbestos imported each year. Imports were counted from 1949, with 1974 as the peak year. Exposure was assumed to run from about age 24 to age 51. Fiber types were not separated.
• Main results:
  • For ages 50 to 74 and occupational exposure only, total projected deaths for 2003 to 2050 ranged from 11,827 to 17,443 across the eight models
  • In Table 4 (ages 50 to 74), the projected peak year was 2010 for model 1, 2015 for models 2 and 3, and 2016 for models 4 to 8
  • For ages 50 to 89 and occupational exposure only, projected deaths for 2003 to 2050 were 15,948 to 53,062
  • Multiplying by 1.25 to account for all exposures (on the assumption that about 80% of deaths are occupational) gave 19,935 to 66,327 deaths for ages 50 to 89
  • In the regulatory-compliance scenario, model 8 projected a peak in 2019 and 23,463 total deaths by 2050. Model 1 projected that the peak had already occurred in 2003, with 4,394 total deaths.
  • The authors reported that more than 60% of deaths would be avoided under regulatory compliance compared with noncompliance
• The authors' conclusion: The authors concluded that mesothelioma deaths could be significantly reduced if workplaces adequately complied with the administrative-level guidelines for occupational asbestos exposure
• Limitations the authors state:
  • Only a short span of reliable death data was used to project deaths over five decades
  • Imports of chrysotile, amosite and crocidolite were not recorded separately
  • Because amosite and crocidolite imports stopped in 1989, future mortality may be lower than projected
  • Exposure from building demolition and disposal of asbestos-containing building materials was not considered. After the 1995 Kobe earthquake, this kind of exposure affected both processors of building materials and the general population.
  • When the model was extended to ages 50 to 89, estimates differed clearly from actual deaths, especially for people in their 80s

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Prognosis, Asbestos Exposure.

Related studies

• Mesothelioma risk and environmental exposure to asbestos: past and future trends in Japan — K. Azuma, I. Uchiyama, et al. (2009)
• Estimation of future mortality from pleural malignant mesothelioma in Japan based on an age-cohort model — T. Murayama, K. Takahashi, et al. (2006)
• Future trends in mortality of French men from mesothelioma — A. Banaei, B. Auvert, et al. (2000)
• Disentangling the effects of various risk factors and trends in lung cancer mortality — X. Wu, J. Zhang, et al. (2025)
• Past trends and future prediction of mesothelioma incidence in an industrialized area of Italy, the Veneto Region — P. Girardi, V. Bressan, et al. (2014)
• A case-control study on occupational lung cancer risks in an industrialized city of Japan — N. Yamaguchi, M. Kido, et al. (1992)

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