Chemoradiotherapy and adjuvant chemotherapy for rectal cancer.

Local recurrence is an important factor in determining the outcome of patients after surgery for rectal cancer, and various attempts have been made to reduce the local recurrence rate. Randomized controlled trials have shown that radiotherapy combined with total mesorectal excision can reduce the local recurrence rate in rectal cancer patients who undergo curative surgery. Chemoradiotherapy is more effective in achieving local control than radiotherapy alone, and preoperative chemoradiotherapy is superior to postoperative chemoradiotherapy in terms of adverse events. Recent advances have led to the identification of potential therapeutic targets such as epidermal growth factor receptor, vascular endothelial growth factor, and endothelial receptors. These new agents have been used in combination with conventional chemoradiotherapy, and higher pathological complete response rates have been reported for such combinations in comparison with conventional regimens. With regard to lateral node dissection, a recent study showed that postoperative chemoradiotherapy was more effective in reducing the local recurrence rate than lateral node dissection. As for adjuvant chemotherapy, one randomized controlled trial showed that patients who received uracil and tegafur as adjuvant therapy had significantly prolonged relapse-free survival times and overall survival times. As well, one metaanalysis has shown the efficacy of oral uracil-tegafur as adjuvant chemotherapy for rectal cancer.