Androgen receptor expression in breast cancer: relationship with clinicopathological factors and biomarkers

Background. Breast cancer is a hormone-dependent tumor. Most breast cancer cells have an androgen receptor (AR), but the clinical value of AR expression is unclear. Methods. AR expression was evaluated in 227 primary breast cancers using immunohistochemistry. The relation of AR expression to clinicopathological factors and biomarkers was analyzed. AR expression was assessed semiquantitatively, and tumors with more than 10% of stained cells were regarded as positive. Results. The AR-positive rate was higher in smaller tumors (P = 0.045), tumors with negative lymph node metastasis (P = 0.045), scirrhous-type tumors (P < 0.0001), tumors of low histological grade (P = 0.0001), and p53-negative tumors (P = 0.0097). Although AR had no relation to menopausal status, 79% of cases of high AR expression (> 50% stained cells) were in postmenopausal women. AR was related to estrogen receptor (ER; P = 0.027) and progesterone receptor (PR; P = 0.016) expression, but showed no relation to human epidermal growth factor receptor type 2 (Her2) expression. Regarding the coexpression of these receptors, 18 of the 42 cases of triple-negative (ER/ PR/ Her2-negative) tumors (43%) were AR-positive. Conclusion. AR expression is related to low malignancy in breast cancer. The assessment of AR expression may lead to new treatment strategies for breast cancer, especially in postmenopausal women and in women with tumors that show triple negativity for hormone receptors.