Is Prostate Cancer Overtreated?
Men With Low-Risk Disease Don't Need Hormone-Blocking Therapy, Researchers Say
Nov. 3, 2009 (Chicago) -- The majority of men with prostate cancer can be
spared anti-hormone therapy -- and all of its side effects, including
impotence, hot flashes, and liver problems, researchers say.
Adding a short course of hormone-blocking therapy to radiation treatment
extended the lives of medium-risk prostate cancer patients but offered no
benefit to low-risk patients when compared to radiation alone, according
to the largest study of its kind.
"Our findings show that men with intermediate-risk disease, which is a
significant minority of patients, gain a benefit in overall survival from the
addition of four months of hormone therapy," says Christopher U. Jones, MD, of
Radiological Associates of Sacramento in Sacramento, Calif.
"Equally importantly, men with low-risk disease, which is the vast majority
of prostate cancer patients, have little to gain from hormone therapy, so they
can avoid all the additional toxicities that come with it," he tells WebMD.
The findings were presented at the annual meeting of the American Society
for Radiation Oncology (ASTRO).
Hormone-Blocking Drugs for Prostate Cancer Became Routine in 1990s
Prostate cancer is the most common type of cancer in men besides skin
cancer, accounting for about one in four of all new cancer cases diagnosed in
men each year. The tumors grow in an environment of the hormone testosterone,
and anti-hormone treatments block testosterone.
Patients are categorized as being low, intermediate, or high risk depending
on such factors as levels of PSA, or prostate-specific antigen, and Gleason
score, a measure of the aggressiveness of the disease.
About 70% of men with prostate cancer in the U.S. have early, low-risk
disease. Another 15% have medium-risk disease, and the rest have high-risk
Doctors began routinely offering anti-hormone treatment to prostate cancer
patients after a large study in the 1990s showed that giving a short course of
hormone-blockers after radiation extended the lives of men with advanced
prostate cancer compared to radiation alone.
"The results were seized upon by radiation oncologists, who assumed that if
hormone therapy is good for nasty cancers, it is probably pretty good for
lower-risk cancers, too," says incoming ASTRO president Anthony Zietman, MD, of
Harvard Medical School.
By the end of decade, concerns about the long-term consequences of the drugs
arose, and doctors began to question whether the benefits outweighed the risk
in lower-risk patients, says Zietman, who was not involved with the
Hormone-Blocking Drugs Don't Benefit Low-Risk Prostate Cancer Patients
To settle the issue, Jones and colleagues randomly assigned about 2,000 men
with low- and intermediate-risk prostate cancer to radiation plus anti-hormone
drugs or radiation alone.
Eight years later, 72% of patients with intermediate-risk cancer who got the
hormone-blocking drugs were still alive, compared with only 66% of radiation
Among patients with low-risk cancer, however, about three-fourths were alive
eight years later -- regardless of whether they got hormone-blocking drugs.
Looked at another way, "only 1% of men in the low-risk group died of their
prostate cancer no matter what treatment they got. Among men with
intermediate-risk cancer, 8% given radiation alone died of their cancer
compared with only 2% who got anti-hormone drugs," Jones says.
Outgoing ASTRO president Tim R. Williams, MD, a private practitioner in Boca
Raton, Fla., tells WebMD that "this is the best data we have and it really
clarifies who does and who does not need hormone therapy after radiation."
Because the men in the study were treated about a decade ago, the techniques
used to deliver radiation have changed, Jones says.
"The question now is, with modern radiation therapy, which is higher dose,
will hormone therapy still benefit the intermediate risk patients?" he says.
Researchers are enrolling men in a large trial to study that question.