Tuesday, June 12, 2007

Prostate cancer therapy may worsen heart threat

Prostate cancer therapy may worsen heart threat

Men at high cardiac risk should remedy those problems before tumor treatment starts, researchers say.

June 9, 2007

Standard treatment for prostate cancer — shutting off the body's production of androgen hormones — can shorten by 2 1/2 years the lives of men who are at high risk of developing heart disease, Boston researchers reported Friday.

The drugs used to suppress the hormones produce anemia, weight gain and insulin resistance, a constellation of factors known as metabolic syndrome.

These effects can sharply increase the risk of a fatal heart attack, especially in men already at high risk, Dr. Anthony D'Amico of Brigham and Women's Hospital in Boston reported in the Journal of Clinical Oncology.

Because the drugs can slow or halt the progression of a prostate tumor, researchers are not advocating that physicians stop using them.

Instead, they say, prostate cancer patients should be screened for cardiovascular risk, and those with risk factors should be aggressively treated for their potential heart disease before cancer therapy begins.

The medical field has come to realize "in the last year or two that hormone therapy has cardiovascular side effects and we need to pay attention to it," said Dr. Eric Klein of the Cleveland Clinic, who was not involved in the study. "I've already changed my practice."

The risk factors, he added, "are correctable and need to be corrected before treatment or concurrently."

The new study grew from a clinical trial of androgen suppression conducted by D'Amico. "I observed that there were a few men receiving treatment who died quickly of a heart attack," he said.

The 206-man sample in his study was not large enough, so he combined his results with data from studies in Canada, Australia and New Zealand. That brought the total number of men to 1,372, about half of whom received both radiation and hormone suppression therapy and half of whom received only radiation.

During the five years the men were tracked, 51 had fatal heart attacks, half of whom had had hormone suppression therapy. But the older men who received the therapy suffered their heart attacks about 2 1/2 years earlier, on average, than those who had not received it.

The heart attacks "occurred within the first six months to two years after treatment," D'Amico said.

"There wasn't an increased number of heart attacks, it is just that they occurred sooner."

The heart attacks affected about 2.5% of the men receiving treatment, he said.

The primary risk factors were diabetes and smoking. Obesity, high cholesterol levels and high blood pressure were also predictive.

D'Amico said he had begun referring high-risk cardiac patients for therapy, which includes aspirin, cholesterol-lowering statins, angioplasty and, for some, open-heart surgery.

"Hormonal therapy in men who need it is lifesaving," he said. But the cure rate "could be even higher if we screen the appropriate men for coronary risk factors."

Experts noted that oncologists had previously used estrogen in prostate cancer patients to suppress androgen hormones, but that use was abandoned in the late 1980s when clinical trials showed an increase in the risk of heart attacks.

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