The role of radiation therapy in rectal cancer

Radiation therapy is an effective but local modality in the treatment of colorectal cancer, with a more clearly defined role in rectal cancer than in colon cancer. In patients with resectable rectal cancer, randomized trials reveal an improvement in local control and survival with postoperative combined modality therapy. Radiation therapy combined with 5-fluorouracil-based chemotherapy appears to be the most effective regimen. Additional benefits with preoperative combined modality therapy may include greater sphincter preservation and less acute toxicity than with postoperative therapy. In patients with locally advanced/unresectable disease, preoperative combined modality therapy increases resectability and may improve local failure rates and overall survival.