But even with those differences considered, men on hormonal therapy had a 56 percent greater chance of developing a blood clot. And the clot risk generally climbed the longer a man was on the treatment.
It's possible, he noted, that hormonal therapy raises the risk of clots because of its negative effects on metabolism, which can include boosting a man's fat mass.
"I think the take-away message is that this reinforces the fact that hormonal therapy has potential risks, and men should be informed," Shahinian said.
Shahinian is a paid consultant to Amgen, which is seeking approval for its bone cancer drug, Xgeva, to treat certain men with advanced prostate cancer.
For many men with prostate cancer, having no immediate treatment at all is an option.
According to the National Cancer Institute, about half of the more than 190,000 U.S. men diagnosed with prostate cancer in 2009 fell into the "low-risk" category -- meaning their cancer had low odds of progression.
They are among the men who can choose to forgo treatment and instead have their cancer monitored -- what doctors call "active surveillance."
Such watchful waiting can be stressful, Shahinian noted. But men should be aware that "doing something" comes with potential risks, he said.
SOURCE: http://bit.ly/tFt8Vx Cancer, online November 9, 2011.