Rectal Cancer Incidence Rose After Radiation Therapy for Prostate Cancer

Excess 10-year risk was roughly one case per 100 men.


A U.S. study demonstrated an increased risk for rectal cancer following external-beam radiation therapy for prostate cancer (JW Gen Med May 3 2005). Now, Israeli researchers have analyzed data from their national cancer registry to address this issue.

Of nearly 30,000 men with prostate cancer diagnosed between 1982 and 2005, 2163 received radiation therapy (either external-beam or brachytherapy), and 26 of these men received subsequent diagnoses of rectal cancer. Compared with the age-adjusted incidence of rectal cancer in the entire Israeli male population, the incidence was significantly higher in the radiation-therapy group (standardized incidence ratio, 1.8). This increase would correspond roughly to one additional case per 100 men during 10 years of follow-up. In contrast, patients who underwent radical prostatectomy did not have excess risk for rectal cancer.


Citation(s):

Margel D et al. Radiation therapy for prostate cancer increases the risk of subsequent rectal cancer. Ann Surg 2011 Dec; 254:947.