Endometrial cancer and microsatellite instability status

Microsatellite instability (MSI) is an important factor in the development of various cancers as an identifier of a defective DNA mismatch repair system. The objective of our study was to define the association between microsatellite instability status and traditional clinicopathologic characteristics of endometrioid type adenocarcinoma. MATERIAL AND METHODS: MSI status of endometrial cancer was examined by employing the Promega MSI Analysis System. This system uses 5 mononucleotide markers to identify MSI in tumour and normal tissue DNA (BAT-25, BAT-26, NR-21, NR-24, and MONO-27), and 2 pentanucleotide markers (Penta C and Penta D) for specimen identification. In this study, we investigated MSI status in 109 endometrial carcinomas. RESULTS AND CONCLUSIONS: One hundred (92%) of 109 endometrial cancers showed endometrioid type histology and only 9 (8%) non-endometrioid type. MSI-high was found in 17% (17/100) of endometrioid type adenocarcinomas, in 0% (0/9) of non-endometrioid carcinomas. Selected clinicopathologic parameters for endometrioid type adenocarcinomas were compared to the MSI status which was separated into two groups – MSI-high and MSI stable. The results showed that MSI-high status was related to clinicopathologic parameters such as deep myometrial invasion and higher histologic grade in endometrioid type adenocarcinomas.