Does TRT cause Prostate Cancer?

Men starting TRT (Testosterone Replacement Therapy) often ask me this question. According to several studies (listed below), there is no clear evidence that elevations in endogenous testosterone (TRT) levels promote the development of prostate cancer in humans. As a result of experimental and historical data on the progression of prostate cancer following TRT, there has been widespread belief that TRT will promote disease progression in prostate cancer patients. Despite these fears, there are a growing number of studies demonstrating no increase in prostate cancer incidence among men on TRT. Furthermore, in studies involving a small number of patients, there has been no discernable increase in disease progression in prostate cancer patients on TRT. While data from large, prospective, randomized, controlled trials are absent, TRT in select prostate cancer patients is likely safe.