Hereditary non-polyposis colorectal cancer syndrome.

Hereditary non-polyposis colorectal cancer (HNPCC) syndrome may account for up to 4% of the total colorectal cancer burden in our community. It is assuming an increasingly important role, both as a clinical management issue and as a model far the application of laboratory and clinical genetic services in cancer detection and prevention. Recent developments in the understanding of the molecular biology of the condition have underpinned recommendations for consideration of genetic testing for DNA mismatch repair gene mutation, recommendations that may have far-reaching implications in terms of the numbers of patients offered genetic testing and for associated costs (both financial and pyschological). The aim of this review is to highlight the clinical, pathologic and molecular biologic features of HNPCC that underlie the clinical management of affected index patients and their at-risk family members.