Radiation Therapy Plus Chemotherapy Before Surgery With or Without Chemotherapy After Surgery in Treating Patients With Rectal Cancer

OBJECTIVES: I. Assess the local recurrence rate, cost-benefit ratio, and acute and late toxicity associated with concomitant preoperative radiotherapy and fluorouracil/leucovorin (5-FU/CF) in patients with locally advanced adenocarcinoma of the rectum. II. Compare the relapse rate, survival rate, disease-free interval, and cost-benefit ratio associated with 6 courses of postoperative 5-FU/CF vs. no further treatment in these patients.

OUTLINE: This is a randomized study. Patients are stratified by tumor stage, age, type of surgery, and participating institution. Patients are randomly assigned to one of two groups. The first group receives radiotherapy to the tumor over 5 weeks and concomitant fluorouracil/leucovorin for 5 consecutive days on the first and fifth weeks. Four to six weeks later, patients undergo complete resection, followed upon recovery by fluorouracil/leucovorin every 4 weeks for 6 courses. The second group receives preoperative chemoradiotherapy followed by surgery, as above, with no postoperative treatment. Patients are followed for survival.

PROJECTED ACCRUAL: A total of 774 patients will be entered on this multicenter study.