ROLE OF PREOPERATIVE IRRADIATION FOR ANAL PRESERVATION IN CANCER OF THE LOW RECTUM

Since 1979, 157 patients with T2, T3, or T4 cancer of the lower rectum have been treated by a short course of irradiation, 30 Gy within 12 days by cobalt 60 using 120-degrees arc rotation on a sacral field, followed by a 2-month rest before surgery. The operative specimens were tumor-free in 13% of patients, Dukes' A in 40% of patients, Dukes' B in 22% of patients, and Dukes' C in 25% of patients. Three (1.9%) patients died postoperatively. At 3 years (107 patients) and 5 years (74 patients) the rates of death of local failure were 7.5% and 9.5%, respectively. The 3-year and 5-year disease-free survival were 71% and 58%. Since 1983, the surgeons took advantage of the tumor regression to carry out sphincter-saving operation in 67 patients with T2, T3, and T4 tumors of the lower third of the rectum. The proportion of patients treated by restorative surgery instead of abdominoperineal resection has grown significantly during the past 4 years, from 22% to 71%. Diverting colostomy was performed in 10 patients. Anastomotic leakages were observed in 7 patients. Of 31 patients who underwent low anterior resection and were followed 3 to 7 years (mean 4.5 years), 5 patients died of distant metastasis and 3 patients are alive after segmental hepatectomy. One patient had local recurrence which was controlled by abdominoperineal resection. The rate of 3-year disease-free survival was 77%. Preliminary results indicate that well planned pre-operative irradiation and delayed surgery can significantly extend the scope of anal preservation for selected patients with cancer of the lower third of the rectum without jeopardizing survival.