Drop in testosterone following radiation therapy for prostate cancer is linked to recurrence of prostate cancer, finds recent research.
Drop in testosterone following radiation therapy for prostate cancer is linked to recurrence of prostate cancer, finds recent research. Specifically, men whose testosterone fell following various forms of radiation therapy were more likely to experience an increase in prostate-specific antigen (PSA)—often the first indication the cancer has recurred.
"The men who had a decrease in testosterone also appear to be the men more likely to see an increase in PSA after treatment," says study author Jeffrey Martin, MD, resident physician in the Department of Radiation Oncology at Fox Chase.
In theory, doctors may one day be able to use testosterone levels to guide treatment decisions, says Martin. "For men with a decrease in testosterone, doctors might intervene earlier with other medications, or follow their PSA more closely than they would otherwise, to spot recurrences at an earlier time."
Martin and his colleagues decided to conduct the study because there is limited information regarding testosterone levels after radiation treatment and what it means for prognosis. To investigate whether a decrease in testosterone has any clinical effects, Martin and his colleagues reviewed medical records from nearly 260 men who received radiation therapy for prostate cancer between 2002 and 2008. The men were treated with either brachytherapy, in which doctors insert radioactive seeds in the prostate, or intensity modulated radiation therapy (IMRT), in which an external beam of radiation is directed at the prostate.
The researchers found that testosterone levels tended to decrease following both forms of radiation therapy. And men who experienced a post-radiation drop in testosterone— particularly a significant drop—were more likely to see their PSA levels rise during the follow-up period.
Still, an increase in PSA—known as biochemical failure—was relatively rare, the authors found. "Only 4% of patients with low-risk prostate cancer had biochemical failure at five years," says Martin.
Advertisement
"Seeing that a drop in testosterone is tied to recurrence is kind of a surprising result," says Martin. "We don't necessarily know what this means yet. I think the relationship between testosterone levels following radiation therapy and prognosis needs more study, and until then it's premature to say this is something patients should ask their doctors about."
Advertisement
Source-Eurekalert