THE REALITY OF RADICAL SPHINCTER PRESERVATION SURGERY FOR CANCER OF THE DISTAL 3 CM OF RECTUM FOLLOWING HIGH-DOSE RADIATION

Purpose: The inordinately high rate of locoregional recurrence following sphincter-preserving surgery for cancer of the distal rectum led to the conviction that restorative surgery was inappropriate for the low level cancer. A rectal cancer management program initiated in 1976 that selectively uses high-dose preoperative radiation and sphincter-preserving surgery produced lower than expected local recurrence rates. Exploring the safety of extending the indication for sphincter-sparing surgery to include post-radiation mobile cancers as low as the 0.5 cm level is the purpose of this report. Methods and Materials: Of 218 rectal cancer patients treated with high-dose preoperative radiation and sphincter-preserving procedures, 69 had radical curative surgery for cancers at or below the 3 cm level. Data regarding the first 52 patients whose ages ranged from 39 to 77 years form the basis of this report. Fifty-seven percent were men. Twenty-five (48%) patients had post-radiation unfavorable cancers (B2, C1, C2). Forty-five to sixty Gy high energy photon radiation was administered over 4 1/2 to 6 weeks followed by a similar interval prior to radical proctosigmoidectomy with anastomosis in the distal 1 cm of rectum. Temporary fecal diversion was performed in all patients; colostomies were closed after 8 weeks. Results: There was zero mortality and two self-limiting anastomotic leaks. Local recurrence developed in 6/43 (14%) patients followed for 24 months or longer. By stage, there were 0/21 (0%) recurrences among O, A, B1 tumors; 6/22 (27%) among unfavorable tumors. By distal margins, 1/9 (11%) occurred in .3-1 cm; 4/13 (31%) 1.1-2 cm; 1/18 (5%) 2.1-3 cm. Five-year Kaplan Meier actuarial survival for the 52 patients was 85%. Conclusion: Our data indicates that sphincter preservation can be accomplished in cancers of the distal 3 cm of rectum if high-dose preoperative radiation is administered and fixed cancers are excluded. This is the first reported study of sphincter-preserving surgery for the distal rectal cancer after high-dose radiation. The data are important to the design of new treatment options.