HIGH-DOSE PREOPERATIVE IRRADIATION FOR CANCER OF THE RECTUM, 1976-1988

Two hundred twenty patients with adenocarcinoma of the rectum have been treated in a program using high dose (> 4000 cGy) preoperative irradiation followed by radical surgical resection. The patients were staged on the basis of pretreatment clinical mobility of the cancers. Seventy-four patients had mobile cancers, 49 had partial fixation (tethered), 85 patients had total tumor fixation, and 12 patients had a frozen pelvis (unresectable). Patients were treated with high energy photons using a four field box technique with total doses ranging from 4000 to 6000 cGy. The overall incidence of local recurrence was 15% (32/220). Patients with fixed and unresectable tumors had a higher incidence of local recurrence, 20% (21/97) as compared with patients with mobile and partially fixed tumors, 10% (13/123). Local recurrence by pathological stage of disease w 6% for patients with Stages O, A, B1 versus 20% for patients with Stages B2 and C cancer. Overall 5-year survival of the total group was 67%. The 5-year survival by clinical stages of disease was 87% for mobile tumors, 74% for partially fixed tumors, 70% for fixed tumors, and 22% for the unresectable group. The 5-year survival by pathological stages of disease was 90% for those with Stage O, A, B1 and 71, 75, and 47%, respectively, for Stages B2, C1, and C2 disease.