Objective  To investigate the correlation between the expression of androgen receptor (AR) and the clinicopathologic characteristics and prognosis of the breast invasive ductal carcinoma (IDC) of various estrogen receptor (ER) statuses.

  Methods  From January to December 2004, 111 cases from ER+ cases and 113 cases from ER- cases were randomly allocated into two IDC groups: ER+ group and ER- group. The protein expression of AR, ER, PR, HER-2, Ki-67, and P53 from the 224 IDC cases were assayed using immunohistochemistry. The current study focused on the assessment of protein expressions in the groups (ER+/AR+, ER+/ AR-, ER-/AR+, and ER-/AR-) and their main characteristics. The prognostic differences in the cases of different AR and ER status were also evaluated.

  Results  The positive rate of AR was 67.9% (152/224), and the rate of AR expression was 80.2% (89/111) and 55.8% (63/113) in the ER-positive and ER-negative cases, respectively. The AR expression in the ER-positive tumors was associated with tumor size, histological grade, pTNM, and endocrine therapy (P < 0.05). The AR expression in the ER-negative tumors was associated with the histological grade of the tumor, HER2 over-expression, and postmenopausal status (P < 0.05). The univariate analysis showed that the patients with AR-positive tumors in the ER+ and ER- groups had significantly better disease-free survival than those with AR-negative tumors (P < 0.001, P=0.046). The Cox regression analysis revealed that AR expression is an independent prognostic factor in the ER+ group.

  Conclusion  AR is expressed in a great number of breast cancers of various ER status and it shows significant correlation with clinical hormone therapy and pathologic prognostic factors. Especially, AR plays a potential role in the clinical management of women patients with ER-negative breast cancer.