What is early-onset cancer?
Early-onset cancer is defined as cancer diagnosed beyond adolescence but before the age of 50 years of age (20-49 years). In addition, early-onset cancers relate to cancer subtypes that most commonly occur in older age groups and are not part of a known inherited genetic syndrome.
Since 2000, there has been an increase in incidence in a number of ‘early-onset’ cancers, including bowel (colorectal), thyroid, breast, prostate and kidney cancer, both in Australia and other parts of the world. It is important to note that these increases reflect relatively small case numbers and cancer remains most common in older people. In 2024 it was estimated 88% of cancers were diagnosed in people aged 50 or more.
Early-onset cancers are likely caused by a complex interplay of several risk factors. These may include changes over recent decades in lifestyle, diet, obesity rates, environmental exposures, and other factors. However, more research is needed to better understand the specific drivers of this trend.
The most important message for all Australians, including young people, is to not ignore any symptoms and discuss any questions that you have with your GP. If you’re concerned about a symptom – especially if it is unusual for you or if it persists – see your doctor without delay. There are also simple things you can do in everyday life that may reduce your risk of cancer: Lifestyle & risk reduction | Cancer Australia.
Cancer Australia is responding to this emerging issue by informing our understanding of early-onset cancers. The following are in development:
- An epidemiological report on trends in cancer incidence in people under 50 years to understand the impact of early-onset cancers in Australia.
- An evidence review of risk factors for early-onset cancers, to understand the potential reasons behind the increase, identify research gaps and interventions aimed at altering the trajectory of early-onset cancer rates in Australia.
- Reviewing and updating evidence-based guidance for GPs to facilitate earlier diagnosis of people with signs and symptoms of cancer, including those under 50 years. These updates will be made to Optimal Care Pathways Step 2 section, which focus on presentation, initial investigations and referral.
In July 2025, Cancer Australia launched the Cancer Australia Research Initiative (CARI), a new grant program aimed at addressing emerging needs in cancer research and including a commitment of $7 million over three years to fund research into early-onset cancers.
