Background
Use of asbestos-containing products was banned in Australia in 2003. However, rates of new cases of mesothelioma 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 2033.
Methods
Data came from the Australian Cancer Database which provides complete national records of mesothelioma cases notified 1982-2019. 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 2020-33 were estimated using Nordpred models.
Results
Amongst older people (55 years+), age-standardised mesothelioma incidence rates increased as the median year of birth approximated 1930. There was a strong birth cohort effect with highest rates amongst those born before 1949. Projection modelling to 2033 suggested that the age-standardised and crude incidence rates of mesothelioma will continue to decline. Most of this decline will be amongst people aged 60-84 years.
Discussion
The findings are consistent with the greatest risk of mesothelioma in Australia occurring with the highest levels of cumulative occupational exposure that occurred historically. Unfortunately, the numbers of new cases are not expected to decline until after 2030.