Modulating the Activity of Androgen Receptor for Treating Breast Cancer

The androgen receptor (AR) is a steroid hormone receptor widely detected in breast cancer. Evidence suggests that the AR might be a tumor suppressor in estrogen receptor alpha-positive (ER alpha+ve) breast cancer but a tumor promoter in estrogen receptor alpha-negative (ER alpha-ve) breast cancer. Modulating AR activity could be a potential strategy for treating breast cancer. For ER alpha+ve breast cancer, activation of the AR had been demonstrated to suppress the disease. In contrast, for ER alpha-ve breast cancer, blocking the AR could confer better prognosis to patients. These studies support the feasibility of utilizing AR modulators as anti-cancer drugs for different subtypes of breast cancer patients. Nevertheless, several issues still need to be addressed, such as the lack of standardization in the determination of AR positivity and the presence of AR splice variants. In future, the inclusion of the AR status in the breast cancer report at the time of diagnosis might help improve disease classification and treatment decision, thereby providing additional treatment strategies for breast cancer.