What is early-onset cancer?
Early-onset cancer is defined as cancer diagnosed beyond adolescence but before the age of 50 years (20-49 years).
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, however, that these increases reflect relatively small case numbers and cancer remains most common in older people. In 2025 it was estimated 88% of cancers were diagnosed in people aged 50 or more. Cancer mortality rates in people in their 20s, 30s and 40s have generally been decreasing over recent decades, reflecting improvements in prevention, early detection and treatment.
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.
Cancer Australia is responding to this emerging issue by informing our understanding of early-onset cancers.
- Cancer Australia commissioned an epidemiological report on trends in increasing cancer incidence in people aged 20-49 years, and an evidence review of risk factors for early-onset cancers to better understand the reasons for the increase and identify interventions to alter the trajectory of early-onset cancer rates in Australia. A summary of the report can be downloaded here (PDF 1.56 MB).
- The review concluded that:
- Cancer incidence is increasing among Australians aged 20 to 49, based on national data from 2000 to 2021.
- Risk factors including alcohol, tobacco, overweight and obesity showed consistent statistically significant associations with early-onset cancers.
- However, there are other emerging potential biological, hormonal, metabolic and genetic factors for early-onset cancers, beyond the ‘traditional’ risk factors for cancer.
- Further investigation and research are warranted to look at risk factors among younger Australians.
- In July 2025, Cancer Australia launched the Cancer Australia Research Initiative (CARI), which supports targeted investment in priority areas of unmet and emerging need, aligned with the Australian Cancer Plan. The 2025 targeted call focussed on early-onset cancers. An investment of $15million over 7 projects was announced in May 2026.
- Cancer Australia is also undertaking a pilot project to develop 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.
