A new analysis from two long-term clinical trials suggests that adding chemotherapy to standard hormone therapy and radiation for high-risk prostate cancer may only benefit men with normal testosterone levels. The study looked at data from 255 men in one trial and 563 in another, all with nonmetastatic high-risk prostate cancer. They were followed for about 10 years.
Researchers compared outcomes for men who received radiation plus hormone therapy with or without the chemotherapy drug docetaxel. Overall, adding docetaxel did not reduce the risk of death for all men. But when the researchers looked at men based on their testosterone levels, they found a different picture.
In men with normal testosterone levels, adding docetaxel was linked to a lower risk of death. In men with low testosterone, there was no clear benefit. The difference between the two groups was statistically significant in both trials, meaning it was unlikely to be due to chance.
This is an early finding from a subgroup analysis, not a definitive result. The effect sizes were not reported, so it is unclear how large the benefit might be. Men with high-risk prostate cancer should discuss their treatment options with their doctor, including whether testosterone testing might help guide decisions.