Prostate Cancer Therapies Raise Heart Risk
But Study Shows Some Anti-Hormone Treatments Are Less Risky Than Others
Sept. 23, 2009 (Berlin) -- The anti-hormone therapies used to treat prostate cancer can raise the risk of heart disease, but some drugs appear to be safer for the heart than others, researchers report.
The study, the largest to date to look at the issue, suggests that overall, anti-hormone therapies were associated with about a 25% increased risk of heart disease.
But in a more detailed analysis by type of hormone therapy, agents known as gonadotropin-releasing hormone agonists proved more risky than anti-androgen drugs, says Mieke Van Hemelrijck, a PhD candidate in cancer epidemiology at King's College in London.
The results were presented at a joint meeting of the European Cancer Organization and the European Society of Medical Oncology (ESMO).
Anti-Hormone Treatments for Prostate Cancer
Prostate cancer is the most common type of cancer in men, accounting for about one in four of all new cancer cases diagnosed in men each year, Van Hemelrijck tells WebMD.
Prostate tumors "grow in an environment of [the hormone] testosterone, so a common treatment is to block testosterone, either by interrupting its production or by making sure testosterone can't get into the prostate," she says.
That can be achieved in one of three ways. Some men undergo surgical removal of the testicles to eliminate the body's main source of testosterone production.
Others receive injections of gonadotropin-releasing hormone agonists. They actually block testosterone production by the testicles, so there is almost no circulating testosterone in the body, Van Hemelrijck says. Examples include Lupron, Viadur, Eligard, Zoladex, Trelstar, and Vantas.
Anti-androgen pills, on the other hand, block testosterone from attaching to prostate cells. "This means there is still testosterone in the body; it just can't get to the prostate," she says. These include Eulexin, Casodex, and Nilandron.
Measuring Risk of Prostate Cancer Treatments
The new study involved more than 30,000 men in Sweden with advanced prostate cancer who received anti-hormone treatments between 1997 and 2006. The researchers compared their rates of heart problems to those in the general Swedish population.
Most of the patients received one treatment, but 38% received both gonadotropin-releasing hormone agonists and anti-androgen pills. The men were followed for about three years.