By Robert Preidt
The analysis of 21 studies revealed that prostate cancer patients who had radiation therapy had a slightly increased risk of bladder, colon and rectal cancers, compared to those who did not receive radiation or had surgery.
However, the rates of these secondary cancers were low, particularly when compared to rates of other complications -- such as urinary incontinence and erectile dysfunction -- associated with prostate cancer treatment, the researchers added. And the study did not prove that radiation treatment caused secondary cancers.
Also, there was no increased risk of lung or blood cancers among those in the radiation group, according to the study published March 2 in the BMJ.
Further research is needed to confirm these findings, but they could help in treatment decisions, especially for patients who are expected to live 20 years or longer, Dr. Robert Nam, from the University of Toronto, and colleagues said in a journal news release.
Anthony Zietman, from the Harvard Radiation Oncology Program and Massachusetts General Hospital in Boston, co-wrote an editorial that accompanied the study. He said the study "confirms our belief that second malignancy should be added to the already long list of avoidable hazards associated with treatment for those men with low-risk prostate cancer who simply need no treatment at all."
But concerns about secondary cancers "should not, however, stand in the way of an effective and well-studied treatment being given to men with higher grade, lethal prostate cancer for whom the potential benefit simply dwarfs the risk," Zietman said.