Sphincter preservation with pre-operative radiation therapy (RT) and coloanal anastomosis: long term follow-up

PURPOSE: To determine the long term follow-up of sphincter preservation with pre-operative RT and coloanal anastomosis for rectal cancer. MATERIALS AND METHODS: A total of 36 pts (M:25, F:11) with invasive, clinically resectable, primary adenocarcinoma of the rectum were enrolled from 1/87 through 4/96 on a prospective Phase I/II trial. All patients were examined in the office by their operating surgeon prior to the start of RT and were judged clinically to require an abdominoperineal resection (APR) due to the proximity (but not invasion of) the tumor to the anal sphincter. By transrectal ultrasound, clinical T stage was T2:5, and T3:31. The median age was 55 years (range: 33-76 years), and the median distance from the anal verge was 4 cm (range: 3-7 cm). The median tumor size was 3.8 cm (range: 1.5-7 cm). Pts received 4680 cGy (180 cGy/day) to the whole pelvis followed by a boost to 5040 cGy followed by surgery 4-5 weeks later. Although no chemotherapy was delivered concurrently with RT, patients with pathologically positive pelvic nodes (13) or metastatic disease (6) received post-operative 5-FU based chemotherapy. All underwent fecal diversion which was closed 2-4 months post-op. Sphincter function was performed using a telephone survey according to the MSKCC sphincter function scale (Excellent: 1-2 bowel movements/day, no soilage, Good: 3-4 bowel movements/day, and/or mild soilage, fair: Episodic > 4 bowel movements/day, and/or moderate soilage, and Poor: incontinence). Actuarial calculations were performed using the Kaplan-Meier method. The median follow-up was 56 months (range: 4-121 months). RESULTS: Of the 35 patients who underwent surgery (1 pt with unresectable liver mets did not undergo surgery) (27(35)) (77%) were able to undergo a coloanal anastomosis and the pathological complete response rate was 14%. Post-operative complications included 1 (3%) partial anastamotic disruption, 2 (6%) rectal stenosis, and 1 (3%) pelvic abscess. For the total group of 36 patients, cumulative local failure as a component of failure was crude: 17%, and 5-Yr actuarial: 21%. The 5-yr actuarial disease free survival was 60% and overall survival was 64%. A total of 9 Pts. were excluded from the analysis of sphincter function (8 underwent an APR, and 1: unresectable liver mets). In the remaining 27 eligible pts. sphincter function was: excellent: 59%, good: 26%, fair: 15%, and poor: 0%. The median number of bowel movements was 2 (range: 0-8). CONCLUSION: Our data suggest that pre-operative RT allows sphincter preservation in 77% of pts. who would otherwise require an APR and 85% have good to excellent sphincter function. Given the moderate local failure rate we now routinely use pre-operative combined modality therapy plus post-op chemotherapy for pts. with clinical T3 disease