Correlation between the expression of BRCA-1 and BAG-1 proteins in triple negative breast cancer and its sensitivity to platinum-based chemotherapy

The aim of this study was to detect the expression of BRCA-1 and BAG-1 in Triple Negative Breast Cancer (TNBC), and analyse the correlation between protein expression and sensitivity to Platinumbased Chemotherapy (PbC). Malignant tissues from 72 TNBC patients who were treated according to the NP and GP programs; then, the relationships between BRCA-1 and BAG-1 protein expression and the survival period (median Overall Survival (OS) and Progression-Free Survival (PFS)) were examined. In TNBC, BRCA-1 expression was related to lymph node metastasis and clinical stage (P<0.01); whereas BAG-1 expression was only related to lymph node metastasis. In TNBC tissues, the expression of BRCA-1 and BAG-1 proteins was significantly positively correlated (r=0.845, P=0.001), and the median OS and PFS of the BRCA-1 and BAG-1-negative group were significantly longer than those of the BRCA-1 and BAG-1-positive group after PbC (P<0.05). In TNBC, the expression of BRCA-1 and BAG-1 was significantly positively correlated, suggesting that these two have synergistic roles in the development of TNBC. The survival rate of TNBC patients with non-BRCA-1 and BAG-1-expressing tumours was higher than that of patients with BRCA-1 and BAG-1-expressing tumours; thus, negativity for BRCA-1 and BAG-1 expression could be used to predict chemo sensitivity of TNBC to PbC.