A comprehensive review of 72 studies addresses the current controversy about testosterone replacement therapy and its potential health risks to men. “We reviewed decades of research and found no compelling evidence that testosterone replacement therapy increases the incidence of prostate cancer or cardiovascular disease,” said Abraham Morgentaler, a urologist at Beth Israel Deaconess Medical Center (BIDMC) and associate clinical professor at Harvard Medical School. “Although it would be helpful to have data from long-term, large-scale studies, it must also be recognized that there already exists a substantial body of research on the effects of testosterone in men.” Since the 1940s researchers have known that severe reductions of testosterone can cause shrinkage of metastatic prostate cancer, and therefore there has been a concern that raising testosterone levels might cause growth of any hidden prostate cancers. However, the study by Ernani L. Rhoden and Morgentaler found no connection between higher testosterone levels and prostate cancer, nor did they find evidence that testosterone treatment causes prostate cancer. Also, studies of testosterone replacement therapy have not demonstrated an increased incidence of cardiovascular disease, myocardial infarction, stroke, or angina, according to the retrospective analysis.