Colorectal cancer is the third most common cancer (excluding
skin cancers) and the second leading cause of cancer-related
deaths in the United States. Each year about 150,000 people are
diagnosed with the disease. Risk factors for colorectal cancer
include age (most cases occur in people over 50), ethnicity
(African Americans and Ashkenazi Jews have particularly high
rates of the disease), a personal history of colon polyps or
colorectal cancer, and the presence of inflammatory bowel
disease (Crohn’s disease or ulcerative colitis). Obesity,
physical inactivity, smoking and heavy drinking have also all
been associated with increased risk for colorectal cancer.
Genetics contribute to a person’s colorectal cancer risk,
although non-genetic factors seem to play a larger role. About
5% of people with colorectal cancer, however, develop the
disease as a result of either familial adenomatous polyposis
(FAP) or Lynch syndrome, two cancer syndromes caused by serious
genetic mutations. Anyone with a family history of c