FRIDAY, June 8, 2007 (HealthDay News) -- The male hormone-suppressing treatment used against aggressive prostate cancer may help bring on earlier heart attacks in older men, new research suggests.
"The new finding is that in men who have risk factors for heart attack, even six months of androgen-suppression therapy [and] maybe as little as three months, can cause a heart attack to occur sooner by about 2.5 years," said lead researcher Dr. Anthony D'Amico, chief of genitourinary radiation oncology at the Dana-Farber Cancer Institute and Brigham and Women's Hospital in Boston.
That finding, which comes from analysis of pooled data of studies in the United States, Australia and New Zealand, does not mean that such men should not be treated to suppress the activity of androgens -- male sex hormones that spur the growth of prostate cancer cells, D'Amico said.
Instead, "the implication is that a man who needs hormonal therapy to avoid dying from cancer but also has risk factors for heart attack should be sent to a cardiologist for assessment and possible treatment of heart disease before starting hormonal therapy," he said.
"We're doing that," D'Amico said. He noted that, "of about 50 men we referred in the last six months, five or six had significant coronary artery disease. They have had it treated and have gone through hormonal therapy without being affected."
The findings are published in the June 10 issue of the Journal of Clinical Oncology.
Androgen suppression therapy (AST), as it is formally called, is reserved for men whose cancer is believed to have spread beyond the prostate or who have an aggressive form that is believed to have spread -- something that occurs in perhaps 40 percent of cases, D'Amico said. "You give these drugs to starve the prostate cancer, and it dies," he said.
Other side effects of AST are well-known. It can cause anemia, increase body fat, reduce muscle and cause an increase in harmful LDL ("bad") cholesterol and a decrease in helpful HDL ("good") cholesterol. But AST is also widely used, because it extends prostate cancer survival.
The new information on the treatment's adverse cardiac effects comes from analysis of data from 1,372 men who received radiation treatment plus AST in three randomized trials and who were followed for at least five years.
A faster onset of heart attacks was observed in men over 65 who got AST for six months, the researchers found.
"This is one more reason to be careful when you recommend hormone therapy," said Dr. Eric M. Horwitz, clinical director of radiation oncology at Fox Chase Cancer Center in Philadelphia. "They do have cardiac side effects."
But AST will continue to be used in many cases, he added. "There is clearly a group of men where the benefits outweigh the risks," he said. "This study shows that you have to weigh the pros and cons of the treatment, who gets benefits and who doesn't."
Men who benefit most are those with "aggressive, bulky prostate cancers," according to Horwitz. "The benefits for them still outweigh the risk in terms of trying to cure the cancer. For men with less aggressive, less bulky cancers, you have to weigh the benefits versus the risks."
Other efforts to get the best effect from AST while minimizing the damage are under way, D'Amico said. One method under study is to stop the treatment now and then. "For advanced prostate cancer, we don't expect to keep the treatment going forever," he said. "You can make it intermittent to get the same survival with less toxicity -- six months on and six months off," he said.
Also, some studies indicate that a shorter course of AST can be effective with fewer side effects -- at least for some patients, D'Amico said. "We need to be better at selecting men for therapy and directing its course," he said.
More information
A guide to prostate cancer is offered by the American Cancer Society.
