Leucovorin and Fluorouracil With or Without SU5416 in Treating Patients With Metastatic Colorectal Cancer

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. SU5416 may stop the growth of colorectal cancer by stopping blood flow to the tumor. It is not yet known whether chemotherapy is more effective with or without SU5416 in treating metastatic colorectal cancer.
PURPOSE: Randomized phase III trial to compare the effectiveness of leucovorin and fluorouracil with or without SU5416 in treating patients who have metastatic colorectal cancer.