[Establishment of a Treatment System for Hereditary Breast Cancer in Our Hospital].

Genetic medicine related to hereditary cancer syndromes has undergone significant changes in recent years. We have summarized the establishment of a genetic medicine treatment system for breast cancer at our institution. From April 2020 to October 2024, there were 11 cases(1.6% of all breast cancer cases)with pathogenic variants in the BRCA1/2 genes. Among all breast cancer patients, there was 1 case of Li-Fraumeni syndrome suspected and the other case of NF1 diagnosed. From January 2020 to October 2024, the comprehensive cancer genome profiling was performed in 23 breast cancer cases, with germline findings identified in CDH1 in 1 case. Genetic testing for asymptomatic relatives and clients with identified germline findings has been established, and Clinical Genomics for outpatients was opened in October 2024. We strive to provide personalized genetic medicine focusing on preventive care for clients and asymptomatic relatives.