Role of endometrial cancer abnormal MMR protein in screening Lynch-syndrome families.

OBJECTIVE: To identify patients with endometrial cancer with potential Lynch-related DNA mismatch repair (MMR) protein expression defects and to explore the role of these defects in screening for LS. METHODS: Endometrial cancers from 173 patients recruited to the Nanchong Central Hospital were tested for MMR (MLH1, MSH2, PMS2, and MSH6) protein expression using immunohistochemistry (IHC). RESULTS: In the 173 tumor tissue samples, the expression loss rates of MSH6, MSH2, PMS2 and MLH1 protein were 16.18% (28/173), 12.14% (21/173), 7.51% (13/173) and 5.78% (10/173), respectively. The total loss rate of MMR protein was 29.89% (27/87). There were 19 patients with a family history of cancer, of which 18 patients demonstrated loss of expression of MMR protein. In the 22 abnormal MMR patients without family history, five families were found to have Lynch-associated cancer (colorectal cancer, endometrial cancer, ovarian cancer, stomach cancer) after follow-up for two years. CONCLUSION: MMR proteins play an important role in the progress of endometrial cancer. The routine testing of MMR proteins in endometrial cancer can contribute to the screening of LS families, especially small families.