Colorectal Cancer: Genetics

Key points

• It is currently thought there are three types of colon cancer:
• sporadic (95%)
• hereditary non-polyposis colorectal carcinoma (HNPCC, 5%)
• familial adenomatous polyposis (FAP, <1%) Studies have shown that sporadic colon cancer may be due to a series of genetic mutations. For example, more than half of colon cancers show allelic loss of the APC gene.
• MSH2 (60% of cases)