Hereditary non-polyposis colorectal cancer or Lynch syndrome: the gynaecological perspective

Abstract

Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch syndrome is characterized by a number of other cancers including colorectal, endometrial and ovarian cancer. This review covers the gynaecological aspects of managing women with HNPCC: diagnostic criteria, molecular tests for diagnosis, cancer risks and different strategies for surveillance and prevention. Studies correcting for ascertainment bias found slightly lower penetrance estimates than those obtained from high-risk families. HNPCC linked ovarian cancer presents at an earlier age and stage and has similar survival rates as sporadic cancer. In endometrial tumours, microsatellite instability or immunohistochemistry has limited effectiveness in selecting individuals for genetic testing, due to molecular differences. Population-based data indicate that a significant proportion of mismatch repair gene carriers would be missed by current clinical criteria. Effective risk prediction models complement clinical risk assessment. Effectiveness of screening is unproven and prophylactic surgery is the best preventive option for women who have completed their families. Multimodal screening protocols from the age of 30-35 years are being evaluated. Risk of endometrial cancer in women with Lynch syndrome is as high as the risk of colorectal cancer. Further research is needed to identify the appropriate strategy for clinical risk assessment and optimize screening. A multidisciplinary approach is necessary to manage these women.