Bowel cancer's demographic shift demands clinical attention

For three decades, bowel cancer has quietly redrawn its demographic boundaries. As the CEO of Bowel Cancer Australia explains, understanding its emerging patient profile is critical as it can foreshadow future cancer burden.

Once thought of as a disease of older Australians, we are now witnessing an alarming rise in early-onset bowel (colorectal) cancer (EOCRC), which is defined as bowel cancer diagnosed in people under the age of 50.¹

While national trends in bowel cancer incidence and mortality in people aged over 50 have generally improved, these headline figures mask a growing risk in younger people, with this uptick emerging in the mid-1990s and continuing to grow.¹

An emerging younger patient profile

New Australian research shows that although 10-year survival rates for EOCRC are encouraging, younger patients are more likely to be diagnosed at an advanced stage.²

The Australian Institute of Health and Welfare reports that the risk of being diagnosed before age 40 has more than doubled since 2000.³ Alarmingly, bowel cancer is now the deadliest cancer for Australian men and the second deadliest for women under 50.³

Unlike later-onset cases, early-onset bowel cancer is often diagnosed after significant delays. Time to diagnosis can be 60% longer for younger people, meaning there can be multiple missed diagnostic opportunities.⁴

Misdiagnosis and missed opportunities

Too often, symptoms in younger people are dismissed or misattributed to haemorrhoids, stress, postpartum changes, irritable bowel syndrome or simply the fatigue of modern life.⁵ Patients describe age-related bias from clinicians, which affects how their symptoms are interpreted and investigated.⁴

An international analysis of nearly 25 million patients under 50 found that the most common red-flag symptoms were blood in the stool, abdominal pain, altered bowel habits and unexplained weight loss.¹ Yet even when these symptoms are present, diagnosis is not always straightforward.

The experiences of younger Australians supported by Bowel Cancer Australia illustrate these systemic diagnostic delays:

• Tiffany (49) collapsed at home and lost a lot of blood. She was told it was likely a burst haemorrhoid. Only after strong self-advocacy was she referred for a colonoscopy, which revealed stage III bowel cancer.
• Sarah (30) experienced black stools and cramping during pregnancy but was denied a colonoscopy. She was later diagnosed with stage IV (metastatic) bowel cancer.
• Jodie (35), a powerlifter, endured eight years of symptoms being attributed to her weight, motherhood and haemorrhoids before receiving a stage III diagnosis.
   

These lived experiences are not outliers. Studies confirm that many EOCRC patients experience their symptoms being minimised or overlooked, especially in primary care.^4,5

The role of GPs in earlier detection

Cancer-specific five-year survival is 94% when detected at stage I or II but drops to just 21% at stage IV.²

GPs play a critical role in recognising red-flag signs and symptoms of EOCRC and referring for further investigation. With bowel cancer now the deadliest cancer for Australians aged 25 to 54,³ there is a need to shift from assumptions based on age to greater diagnostic vigilance.

In 2023, clinical practice guidelines were updated to recommend population screening from age 45 for those at average risk.¹ Additionally, individuals aged 40–44 who request screening can be offered faecal immunochemical testing every two years, following a risk-benefit discussion.¹

However, it is important to note that 46% of EOCRC diagnoses occur in people under 40 — a cohort not yet eligible for routine screening for those at average risk.³

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To support earlier detection, GPs should consider the following strategies:

• Trust symptoms over age, so if a younger patient presents with red-flag signs and symptoms, refer them promptly for colonoscopy.
• Initiate screening discussions with average-risk individuals aged 40 and over.
• Stay informed by completing Bowel Cancer Australia’s free Never2Young CPD training series, available at cpd.bowelcanceraustralia.org.

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Matching response to risk

“You have bowel cancer” are four words you don’t expect to hear when you’re young, yet each year more than 1700 Australians do.³ This shifting age profile demands more than awareness; it calls for a recalibration of clinical thinking. GPs must be empowered to recognise that red-flag signs and symptoms in younger patients are not rare outliers but a growing reality.

Every delayed diagnosis is a missed chance for early intervention and can be the difference between curable and incurable disease. By listening carefully, acting early and embracing updated guidelines, GPs can play a decisive role in helping reverse this trend for the deadliest cancer in people aged 25–54 — bowel cancer.

*Julien Wiggins is CEO of Bowel Cancer Australia.

<sup>1. Markey W, Srinath H. The alarming rise of early-onset colorectal cancer. Aust J Gen Pract. 2025;54(6):392–399. doi: 10.31128/ajgp-05-24-7281
2. Cao AMY, Lonne MLR, Clark DA. Long‐term survival outcomes in young‐onset colorectal cancer: a population‐based cohort study. Colorectal Dis. 2025;27(2):e70007. doi: 10.1111/codi.70007
3. Cancer data in Australia, overview of cancer in Australia. Australian Institute of Health and Welfare; 2024. Accessed July 15, 2025. https://www.aihw.gov.au/reports/cancer/cancer-data-in-australia/contents/overview
4. Lamprell K, Pulido DF, Arnolda G, et al. People with early-onset colorectal cancer describe primary care barriers to timely diagnosis: a mixed-methods study of web-based patient reports in the United Kingdom, Australia and New Zealand. BMC Prim Care. 2023;24(1):12. doi: 10.1186/s12875-023-01967-0
5. Lamprell K, Fajardo-Pulido D, Arnolda G, et al. Things I need you to know: a qualitative analysis of advice-giving statements in early-onset colorectal cancer patients’ personal accounts. BMJ Open. 2023;13(3):e068073. doi: 10.1136/bmjopen-2022-068073</sup>

Top image credit: iStock.com/PonyWang