Neoadjuvant Chemoradiotherapy and Adjuvant Chemotherapy in Treating Patients Who Are Undergoing Surgical Resection for Locally Advanced Rectal Cancer

RATIONALE: Drugs used in chemotherapy work in different ways to stop tumor cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage tumor cells. Chemoradiotherapy (combining chemotherapy with radiation therapy) before surgery may shrink the tumor so that it can be removed. Giving chemotherapy after surgery may kill any remaining tumor cells. PURPOSE: This randomized phase II trial is studying two different regimens of neoadjuvant chemoradiotherapy and adjuvant chemotherapy and comparing how well they work in treating patients who are undergoing surgical resection for locally advanced rectal cancer.

OBJECTIVES: * Evaluate the pathologic complete response rate in patients with locally advanced rectal cancer undergoing surgical resection treated with 2 different regimens of neoadjuvant chemoradiotherapy and adjuvant chemotherapy. * Evaluate the time to treatment failure and patterns of failure in patients treated with these regimens. * Evaluate the incidence of hematologic and non-hematologic grade 3-4 toxicity (preoperatively, postoperatively, and overall) in patients treated with these regimens. * Evaluate the quality of life of patients treated with these regimens. OUTLINE: This is a randomized, multicenter study. Patients are stratified according to clinical stage of tumor (T3 vs T4). Patients are randomized to 1 of 2 treatment arms. Quality of life is assessed at baseline, within 1 week after completion of radiotherapy, within 1 week after completion of adjuvant chemotherapy (12 months), and then at 24 months. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually thereafter.