Androgen receptor expression on breast cancer cells: a clinicopathologic and survival study

Breast cancer is the most common cancer in women around the world. It has been known for over a century that androgens and androgen receptor (AR) play a role in normal and neoplastic breast cells. The aim of this study was to determined the AR expression on tumor cells and its correlation with other prognostic and predictive factors as well as contribution of AR in patients overall survival (OS) and disease- free survival (DFS). This retrospective cross-sectional study performed on 189 patients who referred to Medical Oncology Ward of Cancer Institute, Tehran University of Medical Sciences, from April 2007 to February 2010. We performed an immunohistochemistry study for AR (AR441 clone, Dako, Germany) (10% cut-off point) and Ki-67 MIB-1 clone, Dako, Germany) on paraffin embedded blocks. Other data were extracted from patients’ documents. Overall, AR expression was 49.1%. Mean age of the patients with and without AR was 47.86 and 48.49 years, respectively. AR positive tumors presented more in stage I/II than III/IV (P=0.02) and AR were more positive for estrogen receptor positive, lower grade of tumor (grade I/II versus III) and lower Ki-67 (P=0.01). AR positivity had neither correlation with progesterone receptor, HER2/neu, P53 expression or menopausal status. OS and DFS were higher in AR positive patients but did not reach statistical significance. In triple-negative breast cancer (TNBC) group, 25% of tumors showed AR expression. AR had non-significant positive correlation with OS in TNBC cancer patients. OS and DFS had significant statistic positive correlation with ER, PR and stage regardless of AR status. Based on this study, although androgen receptor expression showed correlation with other prognostic factors for survival in patients, we didn’t find statistically significant independent relationship between AR and overall survival in patients. As far as there isn’t any targeted therapy for triple-negative breast cancer (TNBC), prospective basic and clinical studies regarding AR inhibitors in the treatment of TNBC seems to be logical and valuable.