September 16, 2008 – The battle against cancer is fraught with pitfalls. A Swiss research team estimates that patients who receive radiation therapy to treat prostate cancer increase their risk of developing colon cancer.
Researchers scrutinized the medical records of men who were diagnosed with prostate cancer between 1980 and 1998 in the Geneva area. Of the 1,134 patients selected, 264 had received radiotherapy. Eight of them developed colon cancer within five to nine years of treatment – enough time for a radiation-induced tumor to form.
According to the calculations of the team of researchers, colon cancer would have formed four times more often in these patients than in other Genevans of the same age. Note: Men who were diagnosed with prostate cancer but who did not receive radiation therapy did not increase their risk.
The authors of the study were also interested in the risks for these patients of developing rectal cancer. No link has been demonstrated. A surprising finding, since the rectum is one of the irradiated regions when attacking the prostate.
Previous studies had shown a link between radiotherapy treatments for prostate cancer and rectal cancer. The small sample size in the Geneva study could be to blame.
The good news, however, is that significant progress has been made in radiotherapy in recent years. The rays are now better targeted and less likely to damage the tissue adjacent to the tumor.
Dominique Forget – PasseportSanté.net
1. Rapiti E, Fioretta G, Verkooijen HM, Increased risk of colon cancer after external radiation therapy for prostate cancer, Int J Cancer. 2008 Sep 1; 123 (5): 1141-5.
