Hereditary aspects of colon cancer.

Inherited colorectal cancer syndromes are responsible for a small percentage of all colorectal cancers, but affected individuals are at increased risk of gastrointestinal and extraintestinal malignancies. Gene testing plays an important diagnostic role and guides continued care to the patient and family members. Predisposition to colorectal cancer outside these inherited syndromes is less well defined, but recently established screening guidelines should prove to reduce the incidence of colorectal cancer in those with a familial risk. Colorectal cancer is preventable through recognition, treatment, and proper screening of those at risk.