Cetuximab and/or Bevacizumab Combined With Combination Chemotherapy in Treating Patients With Metastatic Colorectal Cancer

PURPOSE: This randomized phase III trial is studying cetuximab and/or bevacizumab when given together with combination chemotherapy to compare how well they work in treating patients with metastatic colorectal cancer. RATIONALE: Monoclonal antibodies, such as cetuximab and bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Cetuximab may also stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Bevacizumab may also stop the growth of tumor cells by blocking blood flow to the tumor. Drugs used in chemotherapy, such as fluorouracil, leucovorin, oxaliplatin, and irinotecan, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving monoclonal antibodies together with combination chemotherapy may kill more tumor cells. It is not yet known whether combination chemotherapy is more effective with cetuximab and/or bevacizumab in treating patients with colorectal cancer.