Many physicians won’t prescribe testosterone supplements to aging men because they fear they might promote prostate cancer— the second leading cancer-related cause of death in men. Studies from Harvard University, led by Dr. Abraham Morgentaler, showed that low testosterone levels increased the risk of prostate cancer. Dr. Morgentaler noted, “There is not a single study that found any difference whatsoever in cancer outcomes for men with testosterone concentrations of 200, 500, or 800 ng/dL.”
A literature review by Stuart Ellem and Gail Risbridger from Monash University in Australia concluded that the balance between estrogen and testosterone was critical for maintaining prostate health. Testosterone decreases with age, while estrogen increases. High levels of estrogen can promote inflammation and increase the risk of prostate cancer. In some cases, supplemental testosterone improves prostate health.
Source: Journal Steroid Biochemistry Molecular Biology, 118: 246-251