Does low testosterone boost prostate cancer risk? The research gives a confusing answer.

Some research backs that idea: one study found men with low testosterone were 61% more likely to develop aggressive prostate cancer while on active surveillance. Another found that after surgery, men with low testosterone were more apt to have aggressive cancer. But other studies tell a different story. In one, men with low testosterone who took testosterone supplements didn't see their cancer get worse. Another direct study gave testosterone to men on active surveillance and also didn't find a higher risk of progression. So the evidence is split—some suggests low T is a risk factor, and some suggests it isn't.