Between April 1976 and January 1981,80 patients with completely resected adenocarcinoma of the colon who were at high risk for local tumor recurrence received adjuvant postoperative irradiation to the tumor bed. Doses of 4300 to 6300 cGy were delivered to the tumor bed, with no chronic toxicity in 70 of 80 patients. Only two patients required operative intervention for treatment complications. Treatment protocol, selection criteria, and details of irradiation are discussed. Actuarial local failure rates at 3 years were 6%, 596, 1776, 43% for Stages B2, B3, C2, and C3, respectively, and actuarial survival rates at 3 years were 841, 84%, 73%, and 49%, respectively. The survival figures for Stages B3, C2, and C3 appear superior to published historic controls as well as to data from the study institution, and suggest an advantage to the use of adjuvant radiation therapy in patients with moderately advanced colonic carcinomas.
Cancer 57:955-963, 1986.
ADICAL SURGICAL RESECTION remains the primary R therapeutic modality in the curative management of adenocarcinoma of the large bowel proximal to the pelvic peritoneal reflection (ie., colon). Whereas multiple published series have demonstrated a clear benefit to postoperative radiation therapy in adenocarcinoma of the rectum,'-' the role of adjuvant irradiation in the curative management of cancer of the colon has not been defined completely. Data are accumulating from reoperative,I6 and autopsy" series to suggest that local recurrence is a significant problem after resection of colonic as well as rectal cancers. These data suggest that the addition of postoperative adjuvant radiation may decrease local recurrence and improve survival in selected patients with colon cancer. The current analysis was undertaken to assess the morbidity and survival data associated with a course of postoperative irradiation at the Massachusetts General Hospital (MGH) in a series of 80 patients with adenocarcinoma of the colon; all patients had undergone From the