Vaccine Therapy and Chemotherapy With or Without Tetanus Toxoid Compared With Chemotherapy Alone in Treating Patients With Metastatic Colorectal Cancer

RATIONALE: Vaccines 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. Tetanus toxoid may make tumor cells more sensitive to chemotherapy and vaccine therapy. PURPOSE: Randomized phase II trial to study the effectiveness of chemotherapy and vaccine therapy with or without tetanus toxoid compared with chemotherapy alone in treating patients who have metastatic colorectal cancer.