P2-205To establish the procedures of microsatellite instability testing for the solid cancer in our hospital

Abstract Background In December 2018, we can have microsatellite instability testing for the solid tumors in clinical practice in Japan. The microsatellite instability testing was used to check out familial tumors called Lynch syndrome, for which we must care patients with genetic counseling. Purpose To make the rule of the microsatellite instability testing in our hospital, conducting the testing smoothly. Method We discussed with the pathological examination section and listed out several problems suspected with MSI testing. One thing was considering genetic counseling, others were increasing of the burden of each doctors to explain the MSI testing, increasing tasks of the pathological examination section. To resolve these problems, the MSI testing was ordered only by the Doctor of Medical oncology department using the consent form based on the Japanese society for Familial Tumors and arranged by us. If patients needed to genetic counseling, we would consult to Center for Medical Genetics, Shinshu University. With the formal process we decided to make the rule of the MSI testing. Results From December 2018 to the end of February 2019, for 29 patients we had the MSI testing under the rule, which were 9 colorectal carcinoma, 5 soft tissue sarcoma, 3 pancreatic carcinoma, 3 ovarian carcinoma, 3 cervical carcinoma, 3 bile duct carcinoma, 2 endometrial carcinoma, and 1 head and neck carcinoma. Only 1 case among 27 cases whose results were found was MSI-H for the testing. It took 13 days on average to find the test results. There are no problems with the testing. Conclusion To make the MSI testing smoothly, Medical oncologist can play a role of it