Background: Incidence of early-onset cancers (EOC, diagnosed at ages 20-49 years) has increased in Australia and many countries globally. We aimed to identify 'priority' Australian EOCs based on incidence rates and trends, and for those cancers, assess those trends in detail.
Methods: Using Australian Institute of Health and Welfare cancer incidence data, we examined sex-specific cancer incidence trends for those aged 20-49 years, for all cancers combined and 53 cancer types, between 2000-2004 and 2015-2019 (before potential COVID-19 pandemic impacts). Our prioritisation framework identified cancer types with the largest sex-specific absolute incidence increases over that timeframe and a minimum incidence rate (>1.2 per 100,000) at 2015-2019. Sex-specific incidence trends were analysed for these “priority cancers” by period (1982-2024), 5-year age group (20-24 to 45-49 years) and 5-year birth cohort (1930-1934 to 2000-2004). Average annual percentage changes (AAPCs) in incidence rates were reported by age group and sex, using Joinpoint regression.
Results: Between 2000–2004 and 2015–2019, all-cancer incidence among Australians aged 20-49 years increased from 183.9 to 196.7 cases per 100,000 females and from 123.0 to 127.0 cases per 100,000 males. Our prioritisation framework identified 12 higher-priority cancer types: breast, cervical, colorectal, kidney, pancreatic, prostate, testicular, thyroid and uterine cancers, Hodgkin lymphoma, leukaemia, and neuroendocrine neoplasms. Most cancers showed increased incidence rates by birth cohort. Joinpoint regression confirmed statistically significant AAPCs for all 12 prioritised cancers (females 1.1% (95%CI 1.0%-1.2%); males 1.6% (1.4%-1.8%)), and for all cancers combined (females 0.6% (0.5%-0.7%); males 0.3% (0.1%-0.4%)).
Conclusions: The incidence of EOC has increased in Australia, with differences by cancer, sex and 10-year age group. There is an urgent need to investigate the causes of these increases and to develop and implement interventions that address the growing burden of early-onset cancer in Australia and globally.