Mesothelioma Incidence rates in Australia since 1982: exploring age, period and cohort effects and future projections.

Abstract

Background Use of asbestos-containing products was banned in Australia in 2003. However, rates of new cases of mesothelioma, which has a very long latent period between exposure and disease, have continued to increase. The aim of this study was to investigate mesothelioma incidence in Australia by year of birth and age-period-cohort analysis and to develop projections of expected mesothelioma cases to 2034. Methods Data came from the Australian Cancer Database which provides complete national records of mesothelioma cases notified 1982-2020. Incidence rates were age-standardised to the 2001 Australian Standard Population to enable comparisons of the population across time. Age-period-cohort models were used to examine the temporal trends of incidence rates by age, calendar year and birth cohort. Projections for incidence rates of mesothelioma 2020-34 were estimated using Nordpred models. Results Graphs of age-standardised incidence rates of mesothelioma suggest a birth cohort effect and the age-period-cohort model confirmed this. There was a birth cohort effect in all cohorts born before 1960, strongest in cohorts born 1920-1949. Projection modelling to 2034 suggested that the age-standardised rates will continue to decline while crude incidence rates of mesothelioma will stabilise and then gradually decline, mostly among people aged 60-84 years. Conclusions The findings are consistent with the greatest risk of mesothelioma in Australia occurring in cohorts with the highest levels of historical cumulative occupational exposure, showing the value of a ban on asbestos. Impact The number of new cases of mesothelioma per year is not expected to decline until after 2030.