Prostate therapy weakens bones: Study
Fractures due to hormone supression

Few men informed of increased risk

Hormone-suppressing drugs used to treat prostate cancer make men so prone to broken bones that the risks of the treatment may outweigh the benefits in those whose cancer was caught early, researchers say.

Researchers at the University of Texas at Galveston found that in the five years after prostate cancer was diagnosed, men taking such drugs had a 20 per cent risk of fracture, versus 13 per cent among those not getting the treatment.

While prostate cancer kills about 30,000 Americans and 4,200 Canadians a year, it generally grows slowly, and most patients die of some other cause.

At the same time, a broken bone can prove lethal. For elderly people, a serious fracture often starts a downward spiral of slow-healing infections and other complications, confinement to a nursing home or hospital bed, and eventually death. One-third of elderly men who break their hips die of complications within a year.

"If there's no survival benefit and there's potential harm, you should consider whether you should put these men on hormonal deprivation therapy," said Dr. Ronald Morton, director of urologic oncology at the Cancer Institute of New Jersey.

The study, led by Dr. Vakahn Shahinian, reviewed health records of 50,613 men with prostate cancer, age 66 or older. It was reported in yesterday's New England Journal of Medicine.

The researchers blamed hormone-suppressing drugs for an estimated 3,000 fractures a year in Americans with prostate cancer, the second-most common and second-most deadly cancer among men.

About 40 per cent of the 230,000 men diagnosed with prostate cancer in the United States each year get drugs such as Lupron to suppress production of male hormones like testosterone. That is because testosterone, which helps build up bone and muscle, also can induce growth of prostate cancer cells. Those drugs, when combined with radiation, have been proven to save lives among men with advanced prostate cancer.

But in recent years, doctors have also been giving hormone-suppressing drugs to men where there is no clear proof the additional treatment helps.

"What doctors should be telling their patients is, `We don't know that we'll be lengthening your life, but we do you know that we may be increasing your risk of fracture,' " said Dr. Durado Brooks, director of prostate cancer for the American Cancer Society.

Morton and other experts said doctors should also consider giving drugs such as Fosamax that can slow and sometimes reverse bone loss.

The study found that among men surviving five years after their cancer diagnosis, for those getting hormone suppression, the risk of a fracture requiring hospitalization doubled, as did the risk of a spine, hip or upper leg fracture, compared with the group who did not get the treatment.

Morton said doctors generally tell men about the hormone-suppression therapy's other side-effects: loss of muscle mass and strength, loss of some mental sharpness, and hot flashes. But few haveraised the fracture risk until recently, he said.

Associated Press