David G. Mutch, MD

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomaldominant cancer susceptibility syndrome associated with inheriteddefects in the DNA mismatch repair system. HNPCC family membersare at high risk for developing colorectal, endometrial, and ovariancancers. Studies of HNPCC families have helped define the importantrole that mismatch repair genes play in the molecular pathogenesis ofendometrial and ovarian cancers. This review will describe some of theimportant clinical and molecular features of HNPCC-related endometrialand ovarian cancer and describe how genetic susceptibility can beidentified in patients with sporadic endometrial and ovarian cancers. Itis important to identify patients with HNPCC, as families of mutationcarriers may benefit from genetic counseling, testing, and intensifiedcancer surveillance.