Hereditary Nonpolyposis Colorectal Cancer
Purpose of Review: Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant condition that accounts for 2 to 7% of all colorectal malignancies diagnosed annually. Endoscopic surveillance affords a rational strategy for reducing HNPCC-associated colorectal cancer incidence and mortality. The primary objective of this review is to highlight evidence supporting the role of endoscopy, particularly colonoscopy, in the preventive management of HNPCC. Clinical features, diagnostic criteria, and use of genetic testing to identify high-risk patients who warrant surveillance will also be discussed.
Recent Findings: Colonoscopic surveillance has been shown to be an effective strategy for reducing HNPCC-associated colorectal cancer incidence and mortality. Current recommendations for the appropriate use of colonoscopic surveillance are based on an understanding of the natural history of the disease and the ability to identify high-risk individuals using both clinical criteria and genetic testing. High-risk individuals should undergo surveillance every 1 to 2 years beginning at age 20 years and then annually after age 40. Endoscopic surveillance is also recommended every 1 to 2 years following surgical resection of an HNPCC-associated cancer or adenoma because of the high rate of metachronous tumors.
Summary: Endoscopic surveillance remains the mainstay of preventive management of HNPCC. Appropriate use of genetic testing can aid in the identification of high-risk individuals and thereby optimize cost-effectiveness of this approach.

Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, is the most common hereditary form of colorectal cancer, accounting for 2 to 7% of all cases diagnosed annually. In recent years, advances in our understanding of the molecular genetics of HNPCC have resulted in a revised approach to the diagnosis and management of affected individuals and their at-risk relatives. Colonoscopic surveillance remains the mainstay of preventive management. Because optimal use of colonoscopy requires knowledge about the natural history of HNPCC, identification of high-risk individuals, and use of genetic testing, this review will first briefly discuss the clinical features, diagnostic criteria, and genetics of HNPCC and then focus on the role of colonoscopy in patient management.