Long-term survivors after adjuvant pelvic irradiation in rectal and sigmoid carcinoma: an assessment of late results.

Twenty-six patients with adenocarcinomas of the rectum, rectosigmoid, or sigmoid colon given adjuvant pre- or postoperative pelvic radiation therapy followed at least 5 years were retrospectively reviewed to evaluate late tumor control and complication rates. The overall 7-year survival rate was 80 +/- 8% with B2,3 patients faring better than C2,3 (94 +/- 6% versus 43 +/- 19%, p less than 0.005). Local pelvic tumor control was achieved in 23/26 patients (88%); patients with high-stage (C2,3) or poorly-differentiated adenocarcinomas had a higher postirradiation pelvic relapse rate (3/11) versus low stage, well or moderately-well differentiated tumors (0/15). A major complication (none fatal) occurred in 2 of 26 patients (8%) and was not correlated with either irradiation dose nor volume. Long-term follow-up is now available on patients who received adjuvant pelvic irradiation for rectal or sigmoid carcinomas and indicates a high pelvic tumor control rate. The 8% major complication rate may be decreased in the future by more sophisticated irradiation treatment planning.