Inherited colorectal cancer syndromes.

Colorectal cancer is the most common gastrointestinal malignancy and the second leading cause of cancer death in both men and women in the United States. Most colorectal cancer cases diagnosed annually are due to sporadic events, but up to 5% are attributed to known monogenic disorders including Lynch syndrome, familial adenomatous polyposis, MYH-associated polyposis, and the rare hamartomatous polyposis syndromes. These inherited colorectal cancer syndromes confer a markedly increased risk for the development of multiple cancers, and predictive genetic testing is available to identify mutation carriers and at-risk family members. Through personalized strategies for diagnosis and management, a substantial reduction in morbidity and mortality has been appreciated among patients at highest risk for the development of colorectal cancer.