Androgens -- male sex hormones -- make prostate cancers grow faster. Men with prostate cancer may opt to take drugs that block the effects of androgens, or they may remove the source of the hormones, the testicles, via an operation called an orchiectomy.
Because they deprive the tumor of androgens, these treatments are collectively known as androgen deprivation therapy. Androgen deprivation therapy may be offered before other treatments for prostate cancer, especially radiation therapy. It may also be offered after other treatments to prevent or treat recurrent cancer.
There's no doubt androgen deprivation therapy has a benefit. But recently, researchers have uncovered a new risk: heart disease. Studies show increased risk factors for heart disease in men undergoing androgen-deprivation therapy.
Does this mean an actual increase in risk of death from heart disease? Yes, find Henry Tsai, MD, and colleagues.
"We looked at a large population of men with prostate cancer treated with surgery, one or another form of radiation, or cryotherapy. Then we looked at men treated with the same things but also given a short course of androgen deprivation therapy," Tsai tells WebMD. "We found that the men who received androgen deprivation therapy, especially those with surgery as well, had an increased risk of death from cardiovascular disease."
The researchers analyzed their findings according to the patients' age and the primary treatment they received. Among the 3,262 patients who underwent prostate surgery, the 266 men who also received androgen deprivation therapy had a 2.6-fold higher risk of dying from heart disease.
Most of the deaths were in patients aged 65 and older.
"In patients 65 and older with surgery and androgen deprivation therapy, their five-year risk of cardiovascular death was 5.5%. For those who didn't have androgen deprivation therapy, their five-year risk was 2%."
Androgen Deprivation Risk, Androgen Deprivation Benefit
How big is the risk?
"It depends on how you present the information," Tsai says. "It looks like more than a twofold jump in risk, but it is only a 3% difference. It is a significant increase, but in absolute terms it is pretty small."
The study showed no significant risk for men who received androgen deprivation therapy along with other prostate cancer treatments. However, Tsai considers this to be a statistical fluke due to the relatively small number of study patients given treatments other than surgery.
That's also the opinion of Jerome Seidenfeld, PhD, associate director of the Blue Cross and Blue Shield Association's technology evaluation center in Chicago. Seidenfeld's editorial accompanies Tsai and colleagues' report in the Oct. 17 issue of the Journal of the National Cancer Institute.
Seidenfeld warns that while the data from Tsai and colleagues sounds an alarm, there's still too little data to understand the true heart risk from androgen deprivation therapy.
"There is evidence in this paper that those using androgen deprivation therapies are different in a number of ways from patients not using it -- so we don't know if their underlying cardiovascular risk is the same," Seidenfeld tells WebMD.
But Seidenfeld and Tsai agree that doctors should evaluate a patient's risk of heart disease before recommending androgen deprivation therapy -- and that patients considering these treatments should be made aware of this possible risk.
Shehzad Basaria, assistant professor of endocrinology and metabolism at Johns Hopkins University, says his own studies show that every form of androgen deprivation therapy, including orchiectomy, increases a man's risk factors for heart disease.
Basaria says there's a clear benefit to androgen deprivation therapy for men with widely metastatic prostate cancer. And he notes that androgen deprivation therapy also prolongs life when used along with radiation therapy.
The questions arise, Basaria says, for men who had been in remission after treatment for prostate cancer, but who see their PSA levels rising -- a sign that prostate cancer may be coming back.
"Those may be the guys with whom a lot of discussion needs to be held with the oncologist, to discuss the advantages of androgen deprivation therapy in light of these risks," he says.