384P - Prevalence of abnormal microsatellite instability test among ovary and endometrial cancer patients

Abstract

BackgroundMicrosatellite instability (MSI)test has been found and developed with relationship of HNPCC or Lynch syndrome. Its role has been extended from screening marker for Lynch syndrome detection to response marker for immune checkpoint therapy. We investigated to know prevalence of abnormal microsatellite instability (MSI-L/H) among endometrial cancer ovary cancer. MethodsWe identified 51 cases of MSI samples from ovary and endometrial cancer visiting hereditary gynecologic cancer center. ResultsWe found 34 ovary cancer,13 endometrial cancer and 4 colon cancer patients. Median age was 56.6(18∼78). About thirty percent have family cancer history among patient relatives (14/45(31.1%)). Early stage cancer (I∼II) (4/25,16.0%) have higher incidence than late stage cancer (III∼IV) (2/28,7.1%). Abnormal MSI have three serous type and endometrioid type pathology. Among abnormal MSI, we found two MSI-L and four MSI-H (6/51(11.8%)). We found one MSI-H ovary cancer,3 MSI-H endometrial cancer patients (1/34(2.9%),3/13(23.1%)). ConclusionsThere are about 10 percent of abnormal MSI in this study group. Prospective large clinical study is needed for hereditary cancer prevention and precision medicine. Legal entity responsible for the studyThe author. FundingHas not received any funding. DisclosureThe author has declared no conflicts of interest.