I. To determine if adjuvant therapy with one week of continuous 5-FU given within 24 hours of a curative colon resection followed by 6 months of 5-FU/leucovorin is effective in prolonging the disease-free survival and increasing overall survival in patients with Dukes' B3 or C colon cancer, when compared to patients who are treated with 5-FU/leucovorin only.