title: Endoscopic diagnosis and management of hereditary nonpolyposis colorectal cancer.
abstract: OBJECTIVE
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Medicine, Section of Gastroenterology, Boston Medical Center; Boston, Massachussetts 02118, USA.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Bliss
authors.forename: Paul C
authors.initials: PC
authors.lastname: Schroy