Cetuximab and Bevacizumab as First-Line Therapy Followed By Combination Chemotherapy and Bevacizumab With or Without Cetuximab as Second-Line Therapy in Treating Patients With Stage IV 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. Bevacizumab may also stop the growth of tumor cells by blocking blood flow to the tumor. Drugs used in chemotherapy, such as oxaliplatin, leucovorin, and fluorouracil, 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. PURPOSE: This randomized phase II trial is studying how well giving cetuximab together bevacizumab works as first-line therapy, followed by combination chemotherapy and bevacizumab with or without cetuximab as second-line therapy in treating patients with stage IV colorectal cancer.