Postoperative radiotherapy in carcinomas of the rectum and distal sigmoid colon.

Twenty-seven patients with Stage B and C carcinomas of the rectum and lower sigmoid received radiotherapy following radical surgery. Local control ratios for Stages B2, B3, and C (modified Duke's) were 7/9, 2/6, and 4/12, respectively. Nine of these 13 patients are alive with no evidence of disease 4-54 mo. after treatment; the other 4 died of unrelated causes. One died of complications attributable to irradiation 6 mo. after treatment; no tumor was found at autopsy. These results suggest that postoperative irradiation plays a significant role in Stage B lesions, but prognosis for Stage C disease does not appear to be altered.