[Colorectal carcinoma following radiotherapy of gynecological carcinoma]

To assess the risk of radiation-induced cancer of the colon we studied 196 patients with a history of radiation treatment for cancer of the female genital system. After a median follow-up of 12.4 years (range 10-15 years) corresponding to 1172 patient-years, 94 (48%) patients were still alive. 84 (89%) of these patients were evaluated for a second primary cancer to the colon. In 38 (45%) colonoscopic examination was performed. 3 patients were found to have a second primary cancer to the colon compared with 0.32 expected (relative risk 9.3) on the basis of rates from the Zürich Tumor Registry. Due to partial long-term survival, patient non-compliance and non-feasibility of colonoscopic examination, only one fourth of all patients initially treated by radiotherapy for cancers of the female genital system were suitable for colon screening. For these high risk women, colorectal tumor screening should be integrated into a gynecologic tumor follow-up.