Breast cancer arising in a BRCA-mutated background: therapeutic implications from an animal model and drug development.

To date, the presence of a hereditary background has not influenced the selection of drug treatment in breast cancer. However, increasingly, negative hormone receptors and Her2 (often referred to as 'triple negative') or a medullary carcinoma histology has been reported in BRCA mutation carriers. Accordingly, such patients are often considered for adjuvant protocols based on chemotherapy (and not based on endocrine manipulations or trastuzumab). Mouse models introducing a conditional BRCA-null expression in the breast have recently provided powerful support for cisplatin-based treatment and have implications for the design of adjuvant studies in these patients.