Hereditary Non-polyposis Colorectal Cancer/Lynch Syndrome in Korean Patients with Endometrial Cancer

We investigate the frequency of hereditary non-polyposis colorectal cancer among Korean endometrial cancer patients according to two clinical criteria and the uptake rate of a genetic test and genetic status of such patients in routine clinical practice. This was a retrospective study involving 161 consecutive endometrial cancer patients. Patients were classified into clinical and suspected hereditary non-polyposis colorectal cancer. Using direct sequencing, germline mutations were analyzed in the MLH1 and MSH2 genes. There were four (2.5%) clinical hereditary non-polyposis colorectal cancer patients, three of whom underwent genetic testing, and a mutation (c.882delT) in the MSH2 gene was identified in one patient. There were also 14 (8.7%) suspected hereditary non-polyposis colorectal cancer patients, 6 of whom underwent genetic testing; 1 [1/6 (16.7%)] patient had a mutation (c.1757_1758insC) in the MLH1 gene and 1 patient had a sequence variant of unknown significance (c.1886A < G) in the MSH2 gene. Half of the patients (9 of 18) who met clinical or suspected hereditary non-polyposis colorectal cancer criteria declined genetic testing mainly for the reason of financial factor (8 of 9). The proportion of hereditary non-polyposis colorectal cancer [11.2% (18 of 161)] was significant to offer genetic counseling and genetic testing in Korean endometrial cancer patients. Optimal financial support is crucial to increase the uptake rate of a genetic test.