Sphincter preservation for cancer of the distal rectum using high dose preoperative radiation.

Sphincter preservation surgery for cancer of the distal rectum is recognized as being associated with a high incidence of local recurrence. High dose preoperative radiation with new surgical techniques is described as an attempt to widen the scope of sphincter preservation in patients who by conventional management would have an abdomino-perineal resection and permanent colostomy and to reduce the incidence of local recurrence. Since 1976, 121 patients with cancers of the rectum have selectively been treated with high dose preoperative radiation (4000 cGy to 6000 cGy) followed by combined abdominotranssacral resection (56); transanal abdominotransanal resection (28); anterior resection (21), or a full thickness wide local excision (16). This report details the results of 43 patients observed for a minimum of 2 years whose tumors were located from 0-6 cm of the dentate line. All patients received the full course of preoperative radiation, a minimum dose of 4000-4500 cGy in approximately 4 1/2 weeks that was delivered using 180-250 cGy per fraction. Patients with tumor fixation were given an additional boost of 1000-1500 cGy preoperatively. Surgery was carried out 4-6 weeks following the completion of radiation. There was no perioperative mortality. Anastomotic failure occurred in 3 patients and was reconstituted in two. Sphincter function was maintained in all but 6 patients (86%), 2 of these had a subsequent abdominoperineal resection, and 3 a diverting colostomy. Seven of 43 (16%) patients with tumors below 6 cm developed a local recurrence, and 6 of the 7 recurrences occurred in patients with fixed tumors, especially those located from 0-3 cm from the dentate line. Eleven patients are dead of disease. The 5-year actuarial survival rate for this group is 72%. Results indicate that high dose preoperative radiation can significantly extend the scope of sphincter preservation to selected cancers of the disal rectum with excellent survival without increasing the risk of pelvic perineal recurrence.