Combination Chemotherapy in Treating Patients With Resected Colon Cancer

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug is a way to kill more tumor cells. PURPOSE: Randomized phase III trial to determine the effectiveness of uracil, tegafur,and leucovorin compared with fluorouracil plus leucovorin in patients with resected stage II or stage III colon cancer.