Triple-negative breast cancer (estrogen receptor negative, progesterone receptor negative and HER2 negative) is a particularly high-risk breast cancer which does not receive specific therapy targeting these proteins. We report the case of a 23-year-old patient diagnosed with triple-negative breast cancer of the left breast with a family history of breast cancer and carrying a BRCA1 mutation. The classification of breast cancer based on genomic data is required to allow us to optimize therapies and improve the management of breast cancer patients.