Study of Oxaliplatin, Capecitabine and Bevacizumab as First Line Treatment for Patients With Advanced Colorectal Cancer

This study is for people with colorectal cancer, who have tumors that cannot be completely removed by surgery. This study is being done to find out how long it takes tumors to grow after patients receive the drugs capecitabine, oxaliplatin and bevacizumab. Capecitabine (also called Xeloda) is a drug that has been approved by the FDA for treatment of advanced colorectal cancer. Capecitabine prevents some colorectal cancer cancer cells from reproducing, and causes some of them to die. Oxaliplatin (also called Eloxatin) has also been approved by the FDA for treatment of advanced colorectal cancer. Oxaliplatin prevents some colorectal cancer cells from reproducing. Bevacizumab is an investigational drug. Bevacizumab is an antibody (a protein that acts against a specific substance) directed against vascular endothelial growth factor (VEGF). VEGF promotes the growth of blood vessels that bring nutrients to cells. Bevacizumab inhibits the growth of colon cancer cells, by blocking the effects of VEGF. The combination of the drugs used in this study is experimental. The purpose of this study is to see how long it takes patients' tumors to grow when they are taking this combination of drugs.