Neo Adjuvant Chemotherapy in Triple Negative Breast Cancer

Homologous Recombination (HR) is a DNA repair mechanism that can repair double-strand DNA breaks. It is the only reliable repair mechanism that can repair the consequences of DNA adducts caused by bifunctional alkylating agents (such as cyclophosphamide, thiotepa or carboplatin). Alternative DNA repair mechanisms exist, but these unavoidably induce DNA mutations, deletions and chromosome aberrations, giving give rise to genetic instability. HRD may be a consequence of inactivation of the BRCA-1 or BRCA-2 genes (as in hereditary breast cancer), but it may also be caused by defects in the Fanconi anemia pathway or by amplification of the EMSY gene. HRD is present in breast cancer cells but not in healthy cells of BRCA-1 or BRCA-2 mutation carriers, and also in about half of the sporadic triple-negative breast cancers. This phase II/III controlled multicenter trial will investigate the ability of individualized chemotherapy to improve the objective response rate of 'triple-negative' breast cancer (estrogen receptor and progesterone receptor-negative, no HER2 amplification) to preoperative (neoadjuvant) chemotherapy. It will answer the question whether intensified alkylating chemotherapy improves the response rate of tumors with a Homologous Recombination Defect (HRD) and it will gather data required for the design of a phase III study documenting the efficacy of response monitoring by contrast-enhanced MRI in TN breast cancer without HRD.