Vaccine Therapy in Treating Patients With Stage II or Stage III Colon Cancer That Has Been Removed During Surgery

RATIONALE: Vaccines made from a patient's white blood cells and tumor cells may make the body build an immune response to kill tumor cells. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining vaccine therapy with chemotherapy may kill more tumor cells. PURPOSE: Phase I/II trial to study the effectiveness of vaccine therapy combined with leucovorin and fluorouracil in treating patients who have undergone surgery to completely remove stage II or stage III colon cancer.