Neoadjuvant radiochemotherapy for rectal cancer.

During the past few decades, significant progress has been achieved in the management of rectal cancer with the introduction of total mesorectal excision. The role of radiotherapy in improving local control and survival has been investigated extensively. Randomized trials of preoperative radiotherapy reported statistically significant lower local recurrence rates with either short regimens (25 Gy in 5 fractions) or conventionally fractionated regimens (45-50 Gy in 25 fractions) and some also showed a survival improvement. Preoperative radiotherapy appears more effective in terms of local control and toxicity compared to postoperative therapy. Several recent studies show that 5-FU-based chemotherapy enhances tumor response to radiotherapy and preoperative chemoradiotherapy is being increasingly used for stage II and III disease.