Coexistent Loss of the Expressions of BRCA1 and p53 Predicts Poor Prognosis in Triple-Negative Breast Cancer.

Abstract

To investigate the prognostic significance of altered breast cancer susceptibility gene 1 (BRCA1) and p53 expression in triple-negative breast cancer (TNBC). Immunohistochemical expression of BRCA1 and p53 was examined in the tumor tissues of 465 TNBC cases and relations were sought with clinicopathological features and patient survival. Loss of BRCA1 expression was found in 29.5% (137/465) of TNBCs. Positive expression of p53 was observed in 49.9% (232/465). Patients with loss of BRCA1 expression had a tendency to have higher rate of lymph node metastasis (p = 0.075). An association between p53 expression and high histological grade was observed (p = 0.039). TNBC patients with loss of BRCA1 expression had a tendency to have poorer overall survival (OS) than those positive for BRCA1 (p = 0.09). TNBC patients with positive p53 expression showed better OS than those with p53 negativity (p = 0.001). In terms of combined expression patterns, significantly poorer overall survival (OS) was observed for BRCA1-negative/p53-negative TNBCs and best OS for BRCA1-positive/p53-positive TNBCs (p = 0.005). Combined expression patterns of BRCA1 and p53 could serve as useful prognostic markers in TNBC.