The standard treatment for prostate cancer - shutting off the body's production of androgen hormones - can chop 2 1/2 years off the lives of men who are at high risk of developing heart disease, Boston researchers reported yesterday.
The drugs used for suppressing the hormones produce anemia, weight gain and insulin resistance, a group of factors known as metabolic syndrome.
These effects can sharply increase the risk of a fatal heart attack, especially in men who are 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 recommend that prostate cancer patients be screened for cardiovascular risk and that those with risk factors be treated aggressively for potential heart disease before cancer therapy is begun.
"We have recognized ... 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," he said.
The risk factors, he added, "are correctable and need to be corrected before treatment or concurrently."
The new study was an outgrowth of a clinical trial of androgen suppression previously 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 men in his study did not make up a large enough sample, 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 radiation and hormone suppression therapy and half of whom received only radiation.
The study tracked the men for five years. During that period, there were 51 fatal heart attacks distributed evenly among those who had hormone suppression therapy and those who did not. But the older men who received the therapy suffered their heart attacks, on average, about 2 1/2 years earlier than those who did not receive 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 percent of the men receiving treatment, he said. The primary risk factors were diabetes and smoking, although obesity, high cholesterol levels and high blood pressure were also predictive.
D'Amico said he has 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 increased risk of heart attack.
Thomas H. Maugh II writes for the Los Angeles Times.