Here’s a trick question: who mostly get prostate cancer: young men or old men?
The answer is of course that, as with most cancers, older men are much more likely than young men to get prostate cancer.
Then why is it that testosterone has been feared as a cause of prostate cancer?
If testosterone caused prostate cancer, we should see it much more often in young men, who have levels of testosterone peaking around age 30.
Testosterone levels in men peak around age 30, then decline 1 to 3% per year from then on. As a man gets older, and his testosterone level goes down, his risk of prostate cancer increases.