Adjuvant Chemoimmunotherapy for Colorectal Cancer

OBJECTIVES: Assess the efficacy of the addition of levamisole or alfa interferon to fluorouracil and leucovorin calcium (folinic acid) as an adjuvant treatment of intraperitoneal colorectal cancer. OUTLINE: This is a three arm study. Patients are randomized to receive either levamisole, alfa interferon, or no treatment. Arm I: Patients receive levamisole PO for 3 days every 2 weeks for 6 months before and after surgery. Fluorouracil IV bolus and leucovorin calcium (folinic acid) IV over 1 hour are administered on days 1-5 every 4 weeks for 6 cycles after surgery. Arm II: Patients receive alfa interferon-2a SC on 3 alternate days for a week before surgery and for 6 months after surgery. Fluorouracil IV bolus and folinic acid IV over 1 hour are administered on days 1-5 every 4 weeks for 6 cycles after surgery. Arm III: Patients undergo surgery followed by fluorouracil IV bolus and folinic acid IV over 1 hour on days 1-5 every 4 weeks for 6 cycles. Patients are followed every 3 months for 2 years, then every 6 months. PROJECTED ACCRUAL: 350 patients per arm will be accrued for a total of 1,050 patients.