Androgen Receptor as a Potential Target for Treatment of Breast Cancer.

Clinical studies have shown that the androgen receptor (AR) is ubiquitously expressed in breast cancers and this could provide prognostic implication in the diagnosis and treatment of breast cancers. Data from Nurse's Health Study on women with invasive breast cancer suggest that a significant number of tumors were AR-positive as defined by immunohistochemistry. In addition, the distribution of AR among different breast cancer subtypes varies significantly, and the biological reasons for this variation are not well understood. Despite strong histochemical evidence, the AR status is not applied for assessing pathological findings and disease outcome in clinical practice. AR antagonists are not currently used as therapy in breast cancer. This is in part due to conflicting results from early clinical trials with first generation of AR antagonists together with the complexity in breast cancer heterogeneity. In addition, role of AR in breast cancer is not fully understood. Here we will review the role of AR in different subtypes of breast cancers and elucidate its mechanisms. We will also discuss some recent interesting findings on the second generation of AR antagonists for treatment of breast cancer.