How Is Testosterone Related To Prostate Cancer?

Question: How is testosterone related to prostate cancer?

Answer: Testosterone seems to be necessary, but clearly not sufficient to cause prostate cancer since all men -- all normal men -- have substantial levels of testosterone in the blood, and certainly not all men get prostate cancer.

We think that testosterone serves as what might be described as a fertilizer, or a nourishment, that allows the normal growth of prostate tissue and is necessary for the development of prostate cancer. But there are no data that clearly show that testosterone is a direct cause of prostate cancer.