EVALUATION OF PREOPERATIVE RADIATION-THERAPY IN OPERABLE COLORECTAL-CANCER

Materials and Methods Patients with operable colorectal cancer in the ascending colon, descending colon, and rectum were randomized to 500 c Gy before definitive surgery. Patients with stage A and B1 lesions rec eived no further treatment. All patients with stage B2, B3, C1, C2, an d C3 received a minimum of 4500 cGy postoperatively. Results Three hun dred fifty-three patients were registered for the study. Three hundred one patients were available for analyses. Follow-up was a minimum of 5 years on all study patients. The majority of patients had rectal can cer. Complications of treatment were acceptable. Two hundred thirty-on e patients had stage B2, B3, C1, C2, or C3 tumors. Estimated 5-year ra tes for no preoperative therapy versus preoperative therapy were as fo llows: local recurrence 29% Versus 26%; metastasis 41% versus 43%; and survival 54% versus 54%. No statistical benefit was observed for preo perative treatment. Conclusions In a prospective randomized trial desi gned to test the value of low-dose preoperative irradiation followed b y surgery and postoperative irradiation, the authors were unable to ob serve any benefit to low-dose preoperative therapy in patients with un favorable stages.