High-dose preoperative radiation and full-thickness local excision

Abstract

Faced with the responsibility of treating patients with invasive distal rectal cancer who were medically unacceptable for the indicated radical surgery, a prospective study was initiated in which high dose preoperative radiation and full-thickness local excision were used. High dose preoperative radiation permitted full-thickness local excision of select cancers, which, by conventional standards, otherwise would have required radical surgery and permanent colostomy. Feasibility was measured on the basis of safety of the technique, control of the cancer, and the quality of anal sphincter function expected. Patients were selected initially because of their predicted inability to tolerate radical surgery, but indications were broadened to include those whose tumors had completely disappeared after irradiation. From 1984 to 1988, 20 patients underwent 21 operative procedures for cancers located between 0 and 7 cm from the anorectal ring. This report is concerned with the 14 patients of this group who were observed for a minimum of 24 months. High-dose preoperative radiation was administered for a total dose of 4500 cGy. Excision and repair were performed 4 to 6 weeks after completion of radiation therapy. Full-thickness disc or hemicircumferential excision was accomplished by transanal, transsphincteric, and transsacral techniques, which included, in several instances, excision of the sphincter mechanism and perineal body, and/or the vaginal wall. Full-thickness local excision after high-dose radiation therapy for rectal cancers has never been reported. Follow-up observation ranged from 24 to 48 months with a median of 31 months. Rectal reservoir function and sphincter control were good in 13 patients. Local recurrence developed in three patients (21 percent), two of whom had postradiation therapy B2 mucinous cancers. Three-year actuarial rate of local recurrence is 23 percent. One (7 percent) patient died of recurrent disease. Actuarial Kaplan-Meier survival at 3 years is 61 percent. Based on the results of this small, select patient group, high-dose radiation therapy followed by full-thickness local excision appears to be a reasonable option for patients who cannot tolerate radical surgery. This bimodal approach also may serve as an option for those who are good medical risks, but for whom sphincter preservation is at stake, and to whom radical surgery offers limited benefits.