A new paradox for pCR in BRCA mutation carriers

Pathologic complete response (pCR) in neoadjuvant chemotherapy (NACT) in breast cancer and especially in the triple negative subtype (TNBC) is considered an important surrogate end point for disease free survival (DFS), event free survival (EFS) and overall survival (OS) (1). Breast tumors of patients carrying a germline BRCA1/2 mutation represent a subgroup with unique biological characteristics (2). A subgroup analysis of the previously reported GeparQuinto study (3) was recently published by Fasching et al. in the Journal of Clinical Oncology (4) of the TNBC patients who carried a germline BRCA1/2 mutation, and found that the addition of bevacizumab to the NACT regimen of anthracycline/cyclophosphamide followed by weekly paclitaxel, significantly increased pCR rates (ypT0/is-ypN0) to 61.5% vs. 41.2% in the non-bevacizumab arm. However, this increase in pCR was not translated into an improved DFS (HR, 0.74; 95% CI, 0.32–1.69; P=0.472) (4)