Evidence report/technology assessment
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Evid Rep Technol Assess (Full Rep) · May 2007
ReviewHereditary nonpolyposis colorectal cancer: diagnostic strategies and their implications.
Hereditary Nonpolyposis Colorectal Cancer (HNPCC) has been defined clinically and genetically. The disorder has traditionally been recognized in kindreds with a clustering of related cancers in association with mutations in DNA mismatch repair genes. HNPCC is associated with a substantially increased risk for several forms of malignancy but particularly colorectal and endometrial cancer. There were three main objectives of this report: (1) to assess the sensitivity, specificity, and reliability of laboratory and genetic tests commonly used in evaluating patients for HNPCC (analytic validity); (2) to summarize the accuracy of commonly used clinical and laboratory characteristics for predicting the presence of HNPCC in patients with colorectal cancer (clinical validity) and use these estimates to describe the efficiency of various strategies for identifying patients with a mismatch repair mutation; (3) to describe the benefits and harms related to screening and testing patients with colorectal cancer and their family members for HNPCC. ⋯ This report characterizes the accuracy of clinical and laboratory predictors of MMR mutations that can be used to identify patients with an increased risk of having MMR mutations. However, the sensitivity, specificity, and reliability of the tests used to evaluate individuals for suspected HNPCC is not known confidently. Data regarding the net benefits and harms associated with predictive genetic testing in patients with HNPCC-related cancers and their families members is incomplete but suggest that such testing improves compliance with screening procedures. At-risk family members who undergo screening colonoscopy have a reduced risk of developing HNPCC-related cancers and lower mortality. However, all studies supporting these benefits had important limitations.