The role of androgen therapy in prostate cancer: from testosterone replacement therapy to bipolar androgen therapy

Testosterone replacement therapy (TRT) is the primary treatment for male testosterone deficiency. This therapy raises concerns over the risk of prostate cancer (PC), because testosterone has historically been considered the fuel for PC. We discuss the re-evaluation of the relationship between androgen and PC, and highlight the safety of TRT in the treatment of symptomatic men with testosterone deficiency who have low-risk disease after treatment for localized PC with surgery or radiation. Furthermore, we review the clinical application and potential mechanisms of bipolar androgen therapy (BAT) in the treatment of castration-resistant PC, emphasizing that much remains to be done before BAT can be broadly applied.