Sphincter preservation in rectal cancer. Preoperative radiation therapy followed by low anterior resection with coloanal anastomosis.

The advantage of preoperative therapy in patients with clinically resectable transmural rectal cancer is to increase sphincter preservation while obtaining a high likelihood of local control. In patients who undergo a prospective clinical assessment and are declared to require an abdominoperineal resection, preoperative radiation therapy, either alone or when combined with chemotherapy, allows approximately 80% of patients to undergo a low anterior resection with or without colo anal anastomosis. The majority have good-to-excellent sphincter function. This conservative approach may be an alternative to an abdominoperineal resection in selected patients.