Bowel Cancer

Page 1

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

1 FDR 2 FDR >60 - @55

FAP:

Yearly colonoscopy from age 10

Lynch:

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