The expression and clinical significance of the androgen receptor and E-cadherin in triple-negative breast cancer

Triple-negative breast cancer (TNBC) has a poor prognosis and lacks prognostic indicators. The androgen receptor (AR) and E-cadherin are involved in the pathogenesis of breast cancer, but their roles are not clearly defined. We designed this study to evaluate AR and E-cadherin expression and to determine their relationships with the clinicopathologic parameters of triple-negative breast cancer. The present study included 127 TNBC patients. Immunohistochemical stains for AR and E-cadherin were performed, and the relationships between AR and E-cadherin expression and clinicopathologic data and prognosis were analyzed. We found that in TNBC patients, AR was expressed in 16(12.6%) cases, and E-cadherin was expressed in 41(33.0%) cases. AR expression was associated with tumor grade (P = 0.004) and menopausal status (P = 0.017), and E-cadherin expression was associated with node status (P= 0.016). A multivariate analysis demonstrated that tumor size, tumor grade, lymph node status, and E-cadherin were of prognostic significance for disease-free interval and overall survival. Compared with AR-positive patients, AR-negative patients showed significantly poorer outcomes with respect to the disease-free interval (P = 0.047) and overall survival (P = 0.038). E-cadherin-negative patients experienced shorter disease-free interval (P = 0.016) and poorer overall survival (P = 0.012) than did E-cadherin-positive patients. An AR-positive and E-cadherin-negative expression profile was associated with recurrence or metastasis (P = 0.036). Moreover, as the expression of nuclear AR increased (25% vs. 33.3%, P = 0.361), less E-cadherin staining was observed in TNBC samples. This finding suggested that AR and E-cadherin expression could be a useful prognostic marker for classifying subgroups of TNBC.