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
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
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
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
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
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.
Overall, anti-hormone therapies were associated with a 24% increased risk of
heart attack, a 19% increased risk of irregular heartbeats known as
arrhythmias, a 31% increased risk of ischemic heart disease, and a 26%
increased risk of heart failure. The risks began to climb within a few months
of starting hormone therapy.
Prostate cancer patients treated with anti-hormone therapies also had a 22%
to 41% higher chance of dying of a heart attack or other type of heart disease,
compared with the general population.
But further analysis showed that while all three forms of anti-hormone
therapy were associated with an increased risk for heart disease,
anti-androgens were associated with the lowest risk." Patients on
gonadotropin-releasing hormone agonist therapy had the highest risk of these
problems," Van Hemelrijck says.
For example, men given anti-androgen pills had a 15% increased chance of
developing ischemic heart disease vs. a 33% increased risk in the men who
received gonadotropin-releasing hormone agonists.
Since men given anti-androgens still have circulating testosterone in the
body, the findings "support support the hypothesis that testosterone is
protective for the heart," Van Hemelrijck says.