Early onset colorectal cancer

• Published in: BMJ. British medical journal (Clinical research ed.) Vol. 389; p. e082452
• Main Authors: Chambers, Adam C, Merriel, Samuel W D, Beard, Glenda, Greer, Helen, Messenger, David E, McCarthy, Kathryn
• Format: Journal Article
• Language: English
• Published: England British Medical Journal Publishing Group 09.06.2025; BMJ Publishing Group LTD
• Subjects: Abdomen; Age; Antibiotics; Bioavailability; Bleeding; Cancer screening; Cohort analysis; Colon cancer; Colorectal cancer; Colorectal carcinoma; Defecation; Diagnosis; Dysbacteriosis; Episiotomy; Gastrointestinal cancer; Hemorrhoids; High fat diet; High income; Intestine; Irritable bowel syndrome; Medical diagnosis; Medical screening; Older people; Patients; Pelvis; Postpartum period; Practice; Primary care; Rectum; Risk factors; Young adults; New Zealand; Canada; United Kingdom > UK; United States > US; Denmark; England; Australia
• ISSN: 1756-1833; 1756-1833
• DOI: 10.1136/bmj-2024-082452

Correspondence to: K McCarthy, Department of Colorectal Surgery, Southmead Hospital, Bristol BS10 5NB Kathryn.mccarthy@nbt.nhs.uk What you need to know Early onset colorectal cancer refers to diagnoses of colorectal cancer in people under 50 years of age For younger people, incidence of colorectal cancer is increasing globally, and colorectal cancer is predicted to be the commonest cause of all cancer related death by 2030 Rectal bleeding is the commonest reported symptom in younger people, and, compared with older people, these patients are more likely to present with advanced disease, which is located on the left side of their colon (rectal and sigmoid tumours) Younger people may experience delays in diagnosis if symptoms such as abdominal bloating or cramping and occasional rectal bleeding are incorrectly attributed to non-cancer diagnoses such as irritable bowel syndrome or haemorrhoids Investigate younger people by taking a thorough history, performing abdominal and digital rectal examinations, and carrying out blood tests and faecal immunohistochemical testing A 32 year old woman presented to her GP with a four week history of a prolapsing anal lump after defecation. There is substantial interest in the role of gut dysbiosis because of the complex interplay between high fat diets, obesity, antibiotics, and exposure to environmental chemicals that increase the bioavailability of nitrates (such as used in processed meat preservation, with higher exposure linked to higher risk).1213 It is possible that these non-hereditary risk factors are shared between early onset colorectal cancer and other gastrointestinal cancers arising in young adults. In 2020, colorectal cancer ranked third worldwide in terms of incidence, but second in terms of mortality.14 This is predicted to rise to first position by 2030, with the current annual rise in incidence in people aged under 50, as reported by GLOBOCAN 2020, a worldwide population database estimating cancer-specific rates for 185 countries and territories.14 Early onset colorectal cancer makes up approximately 10% of all new colorectal cancer diagnoses.1516 This proportion is expected to increase; for example, in England between 1994 and 2015 there was a 51% increase in early onset colorectal cancer diagnoses.17 Population-level data from NHS Digital shows that the annual incidence of early onset colorectal cancer in 2015 was 1.3 per 100 000 in 20–29 year olds, 8.1 per 100 000 in 30–39 year olds, and 16.7 per 100 000 in 40–49 year olds.17 There was no difference between men and women. In the same study, when compared with older age groups, people under 50 more frequently presented with non-specific symptoms on a single occasion and had a lower proportion of presentations with red flag symptoms.27 In a mixed-methods analysis of 273 patient accounts of the diagnostic barriers at primary care level in the UK, Australia, and New Zealand, 24% of patients attributed a delay in diagnosis to a missed diagnostic opportunity.28 Financial concerns may stop some people seeking medical attention and may prevent community doctors from referral to secondary care in healthcare systems with limited resources.29 Furthermore, there are no universal screening programmes for early onset colorectal cancer globally; countries that do offer bowel cancer screening typically start at 50 years of age.30 Longer diagnostic intervals are associated with more advanced stage of cancer according to data from seven independent datasets from high income countries (Scotland, England, Canada, Denmark, and Spain).31 In a UK retrospective cohort study of 4836 patients that used linked cancer, primary care, and secondary care registry data, the median interval from the patient first experiencing the symptom to first investigation was 131 days for colon cancer and 43 days for rectal cancers in patients aged under 45 years, compared with 65 days for colon cancer and 58 days for rectal cancer in people aged 55-64 years.32 These data are corroborated by