Adjuvant therapy of rectal cancer.

For patients with clinically resectable stage T3 and/or node-positive rectal cancer, adjuvant radiation therapy decreases the rate of local recurrence. The addition of systemic chemotherapy further enhances local control and improves survival. Compared with postoperative therapy, preoperative treatment may have less toxicity and may increase the chance of sphincter preservation. The acute and long-term toxicity of pelvic radiation is related to the technique of delivery. Therefore, appropriate conventional radiation doses and techniques are recommended. Randomized trials comparing preoperative and postoperative combined modality therapy are in progress.