The changing face of familial colorectal cancerBMJ 2004; 330 doi: https://doi.org/10.1136/bmj.330.7481.2 (Published 30 December 2004) Cite this as: BMJ 2004;330:2
- Ayan Banerjea, clinical research fellow (email@example.com),
- Sue Clark, consultant colorectal surgeon,
- Sina Dorudi, professor of surgical oncology
- Centre for Academic Surgery, Barts and the London Queen Mary School of Medicine and Dentistry, Royal London Hospital, London E1 1BB
Young patients with colorectal cancer should be assessed for genetic predispositions
Colorectal cancer is predominantly a disease of elderly people in the developed world. The annual incidence of more than 35 000 cases in the United Kingdom means that many people have at least one affected relative. Colorectal cancer in elderly relatives may be due to shared environmental exposure rather than a true genetic predisposition, although the risk of developing colorectal cancer rises with the number of relatives affected. Genetic factors may have a role in up to 30% of cases,1 but only a small proportion (less than 5%) of colorectal cancers arise in families with strong histories in which tumours develop at a young age (less than 50 years) and represent truly high risk inherited predispositions. Even so, more than 1500 families per year need to be counselled and screened.
Most hereditary colorectal cancers are attributable to two recognised syndromes. Familial adenomatous polyposis usually has a clear phenotype, characterised by numerous (more than 100) adenomatous polyps in the large bowel by the second to third decades of life, which inevitably progress into cancers. This autosomal dominant condition, caused by APC gene mutations, has been a paradigm for the …