Pre- or postoperative radiotherapy in rectal and rectosigmoid carcinoma. Report from a randomized multicenter trial.

Between October 1980 and December 1985, 471 patients with a resectable rectal carcinoma entered a randomized multicenter trial for comparison of pre- and postoperative irradiation. Two hundred thirty-six patients were allocated to receive high-dose fractionated preoperative irradiation (total dosage, 25.5 Gy in five to seven days) and 235 patients to receive postoperative irradiation to a very high dosage level with conventional fractionation (60 Gy in a total 8 weeks). The postoperative treatment was delivered only to a high-risk group of patients (Astler-Coller stages B2, C1, and C2). The preoperative irradiation was well tolerated, with no immediate irradiation-related complications and no increased postoperative mortality (3%, 7 of 217 patients, compared to 5%, 10 of 215 patients in the postoperatively irradiated group). More patients in the preoperative irradiation group had perineal wound sepsis after abdominoperineal resection and this prolonged the stay in hospital after surgery. In 50% of the patients the postoperative treatment could not be commenced until more than 6 weeks after surgery. The postoperative treatment was not as well tolerated as the preoperative one. The local recurrence rate was statistically significantly lower after preoperative than after postoperative radiotherapy (12% versus 21%; p = 0.02). In both groups more patients developed a local recurrence if the bowel was perforated at surgery or if the resection line was microscopically close to the tumor. To date, with a minimum follow-up of 3 years and a mean follow-up of 6 years, there is no difference in survival rates between the two groups.