Metastatic Colorectal Cancer As the Primary Phenotype in a Hereditary Breast and Ovarian Cancer Patient with Germline BRCA1 Mutation: a Case Report

Hereditary breast and ovarian cancer (HBOC) syndrome has increased predisposition to breast and/or ovarian cancer, and 24% of families with HBOC were associated with the germline pathogenic variants in BRCA1/2. Timely diagnosis and identification of mutation carriers is of utmost importance to improve survival benefit and quality of life. Cancers that have been included into screening of BRCA1/2 associated HBOC included prostate and pancreatic cancers etc. In this case, we reported a patient who firstly presented symptoms of CRC and was finally diagnosed as BRCA1 associated HBOC with advanced peritoneal carcinoma. With strategies of cetuximab based treatment and olaparib, and debulking surgeries, she has achieved an overall survival (OS) > 35 months. The aim was to indicate that HBOC might also first present as CRC, and comprehensive next-generation sequencing analysis might be a key complement for screening and diagnose of HBOC.