High dose preoperative radiation and sphincter preservation in the treatment of rectal cancer.

Abdominoperineal resection and permanent colostomy have been the mainstay of treatment for rectal cancer. Automatic stapling devices have widened the scope of low anterior resection, permitting sphincter preservation for tumors originating in the upper and middle thirds of the rectum. Attempts at sphincter preservation in low rectal cancer has resulted in higher recurrence in the pelvic/perineal tissues (41%, MSKCC). In 1976, we undertook a study to expand the scope of sphincter preservation in patients with rectal cancer. Patients were selected because of the presence of unfavorable tumors or low level of rectal area (3 and 6 cm from the dentate line). Forty-three patients were treated in this program. Follow-up ranges from 24 to 96 months, with a median follow-up of 36 months. Fifteen patients were selected for unfavorable tumor types and 28 patients were selected for low level of tumor, between 3 and 6 cm. Twenty of the 28 patients with low level tumors also had unfavorable tumors. All patients received the full course of preoperative radiation (4000 to 4500 cGy in 5 weeks). Surgery was carried out 4 to 6 weeks following radiation and consisted of a sphincter saving procedure, usually by combined abdominotranssacral resection. There was no perioperative mortality. A single anastomotic breakdown required reconstruction. Thirteen patients in this group have died, 9 of these with disease and 3 without evidence of tumor. There were 6 (14%) local recurrences in the pelvic/perineal area. Survival of all patients at 4 years is 66%. This early experience indicates that the high dose preoperative radiation can minimize local recurrence in unfavorable cancers and allows sphincter saving surgery to be performed with small, safe margins in the lower rectal cancers.