Prostate Radiation Linked to Rectal Cancer
Radiation Treatment for Prostate Cancer May Double Rectal Cancer Risk
April 1, 2005 - Men who receive radiation treatment for prostate cancer are
more likely to develop rectal cancer, a new study suggests.
Researchers found that men with prostate cancer who were treated with
radiation had a 70% higher risk of developing rectal cancer than those who were
treated with surgery only.
"Men who have had prostate radiation should be aggressively monitored
for rectal cancer starting five years after treatment," says researcher
Nancy Baxter, MD, PhD, of the University of Minnesota Cancer Center, in a news
release. "This is the first time rectal cancer risk associated with
prostate radiation has been quantified, and these findings may also have
implications for patients treated with radiation for other pelvic
most commonly diagnosed cancer in the U.S. with about 230,000 men diagnosed
with the disease each year. Although prostate cancer is highly treatable when
caught in the early stages, researchers say men who survive prostate cancer may
face higher risks of other types of cancer due to the effects of their
About 17% of men with prostate cancer are
usually because they choose radiation over are older, or
have other medical problems.
In the study, which appears in the April issue of Gastroenterology,
researchers looked at more than 85,000 men treated for prostate cancer from
1973 to 1994.
More than 30,000 of the men received radiation treatment for prostate cancer
and about 55,000 had surgery only.
The results showed that radiation treatment was linked to a higher risk of
cancer in areas that were irradiated, such as the rectum, but not in the
remainder of the colon. The risk of developing
who received radiation was 70% higher than those who underwent surgery
Researchers say that increase in risk is roughly equivalent to the
associated with having a family history of the
Improvements With Current Technology
However, researchers say current technology allows for more targeted
radiation treatment to the affected area than was available up to 1995. Even
so, researchers say some portions of the rectum may still receive a high dose
of radiation, which raises the risk of rectal cancer.
In an editorial that accompanies the study, William M. Grady of the Fred
Hutchinson Cancer Research Center in Seattle and Ken Russell of the University
of Washington Medical School say that the results highlight the need to monitor
the long-term health of prostate cancer survivors.
"In light of the increasing number of men surviving prostate cancer,
these findings have substantial implications not only regarding our
understanding of radiation-induced cancers but also for our management of men
who have undergone prostate irradiation," write the editorialists.
"As more men are successfully treated for their prostate cancer, the
prevention of long-term complications from prostate cancer treatment can be
predicted to become a major medical issue."