Bowel Cancer

^^ Affected FDR (2-3x more likely) - 1 relative

1 FDR 2 FDR >60 - @55FAP:Yearly colonoscopy from age 10Lynch:Yearly-biyearly colonoscopy from age 25 (or 10 years before earliest relative)

Mutation in the APC gene 100s to 1000s of polyps develop in the bowel on average at age 15 years By age 35, 95% of individuals have polyps Mean age of colon cancer diagnosis 39 years (in untreated)  Without colectomy, colon cancer is inevitable Other cancers that are associated: small bowel, pancreas, thyroid, CNS (usually medulloblastoma), liver, bile ducts, stomach  Other features: osteomas (boney growths), dental abnormalities, congential hypertrophy of the retinal pigment epithelium, fibroids, desmoid tumours (benign)  

Mutation in MLH1, MSH2, MSH6 or PMS2 MLH1 or MSH2 mutation - men 69% risk or CRC, women 52% Lower risk with MSH6/PMS2 - 15-44% men, 15-20% women Mean age of diagnosis 45 years Other associated cancers: endometrial, ovarian, gastric, biliary tract, uro-epithelial, kidney and brain

Risk factors

fap

lynch syndrome

screening