Adjuvant postoperative radiotherapy in locally advanced rectal and rectosigmoidal cancer.

A pelvic recurrence is the cause of death in about 1/3 of radically operated patients for rectal and rectosigmoidal cancer without clinical evidence of distant metastases. Preoperative and postoperative radiotherapy are largely used to reduce the incidence of locoregional relapses and to improve disease-free and overall survival and quality of life. Benefits from radiotherapy have been widely demonstrated, and adjuvant postoperative radiotherapy is at present strongly recommended. Twenty-one patients with locally advanced (stage B2, B3, C) rectal (11 cases) and rectosigmoidal cancer (10 cases) were treated with postoperative radiotherapy at the National Cancer Institute of Milan from 1975 to 1978. The pelvis received a median dose of 4500 rad (range, 4000-5200 rad) in 5 to 7 weeks through AP, PA opposed fields; 6 patients received a boost of 1000 rad on the perineum. Median follow-up after surgery is 83 months (range, 24-63 months). Only 1 case (< 5%) had a pelvic recurrence, at the perineum. The expected recurrence rate after surgery alone is 40% and our favorable results after postoperative radiotherapy are comparable with recent data from other institutions. Radiotherapy side effects were moderate and transient; no late damages to small bowel were observed.