For men with aggressive prostate cancer, hormone-targeted therapy cuts the overall risk of death, according to a new review of past studies.
It also does not increase the chance that men will die from cardiovascular disease, which some research had suggested might be the case, researchers reported in the Journal of the American Medical Association on Tuesday.
"I think that these results should be very reassuring for the majority of patients who are thinking of androgen deprivation therapy for their prostate cancer," said Dr. Paul Nguyen, the lead author on the study from the Dana-Farber Cancer Institute and Brigham and Women's Hospital in Boston.
"To a certain degree, the pendulum may have swung too far in the opposite direction away from using hormone therapy in men that would benefit from it," he told Reuters Health.
The National Cancer Institute estimates that about 241,000 men will be diagnosed with prostate cancer in 2011 and close to 34,000 will die of the disease.
So-called androgen deprivation therapy, or ADT, has been the standard of treatment for men with more aggressive, high-risk prostate cancers. The drugs suppress the body's production of testosterone, which is known to speed cancer growth.
But they've also been linked to side effects including hot flashes, weight gain, diabetes and loss of sex drive and, more recently, to cardiovascular risks. One recent study linked hormone-targeted therapy to an increased risk of blood clots.
To see whether heart risks held up in rigorous trials, Nguyen and his colleagues combined data from 11 studies that randomly assigned men with high-risk prostate cancer to receive hormone-targeted therapy or not, then followed them for about a decade, on average.
The studies included about 2,500 men that were treated with androgen deprivation therapy over anywhere from three months to indefinitely, and 2,300 that weren't.
During the follow-up period, 38 percent of men getting hormone-targeted therapy died for any reason, compared to 44 percent of those not on the drugs.
The differences were more pronounced in deaths specifically due to prostate cancer: 14 percent of men on the drugs died from their cancer, compared to 22 percent in the "control" groups.
When it came to conditions like heart disease and stroke, however, there was no difference based on treatment, about 11 percent of men in both groups died of cardiovascular causes, in the eight studies that looked at that outcome.
In more specific analyses, the researchers still found no extra risk of cardiovascular death from the drugs in men older or younger than 70, or in those that were treated with the hormonal therapy for either less than six months or more than three years.
Dr. Behfar Ehdaie, a urologist at the Memorial Sloan-Kettering Cancer Center in New York who wasn't involved in the new study, said it "reinforces the idea" that patients with intermediate or advanced prostate cancer also being treated with radiation benefit from hormone-targeted therapy.
But, he told Reuters Health, "the risk should still be discussed with patients."
It's important to consider, he added, that the analysis did not look specifically at prostate cancer patients who also had risk factors for cardiovascular disease, or had suffered a heart attack or had heart failure in the past.
More research is needed to see if those men, in particular, have an extra risk of dying from cardiovascular disease if they're treated with androgen deprivation therapy, Ehdaie said.
The researchers agreed. "It's really just for that group of men that has severe cardiovascular disease where I think we should still be cautious," Nguyen said.
He said that the report also doesn't address other side effects of hormone-targeted therapy that may not necessarily increase men's chances of dying.
"Our study does not leave ADT off the hook in terms of causing things like increased insulin resistance and diabetes," Nguyen said. "There could very well still be some adverse cardiovascular consequences that don't lead to death."
Ehdaie emphasized that "there's not been a clear benefit" to androgen deprivation therapy in men with less-aggressive prostate cancer, and this review only included men who had high-risk disease.
"In situations where androgen deprivation has clinically-proven benefits, patients and physicians should work together to prescribe these medications," he concluded.