Radiation for Prostate Cancer Raises Risk of Other Cancers

May 20 -- MONDAY, May 19 (HealthDay News) -- Men undergoing external beam radiation for localized prostate cancer may have a slightly increased risk of developing other cancers, researchers report.

The findings could have implications for men trying to decide which treatment is best for their prostate cancer, the researchers said.

"We saw an increased risk for lung, bladder and rectal cancer among patients treated with external beam radiation for prostate cancer," lead researcher Dr. Naeem Bhojani, from the University of Montreal's Department of Urology, said during a Monday teleconference at the American Urological Association annual meeting, in Orlando, Fla.

"However, in absolute terms, the absolute risk associated with the development of secondary malignancies in patients exposed to external beam radiation therapy is quite small," Bhojani said.

Among the treatments for prostate cancer are surgical removal of the prostate, called radical prostatectomy; implanted radioactive seeds that deliver radiation specifically to the prostate gland; and external beam radiation, which is a non-surgical procedure that delivers radiation to the prostate from outside the body.

Bhojani said external beam radiation is probably a better treatment choice for older patients rather than younger patients with longer life expectancies, who may be at risk for developing these secondary cancers.

For the study, by researchers from Canada, Italy and the United States, Bhojani's group collected data on 10,333 men being treated for localized prostate cancer. Among these men, 6,196 had their prostate surgically removed, and 4,137 underwent external beam radiation.

The researchers then looked at the later development of bladder, lung and rectal cancer, to see which treatment was more likely to increase the risk of these malignancies.

They found that men who'd undergone external beam radiation had a threefold increased rate of bladder cancer, a 1.8-fold increased rate of lung cancer, and a 1.7-fold increased rate of colorectal cancer, compared with men who underwent radical prostatectomy.