Study of Bevacizumab Combined With Capecitabine and Either Oxaliplatin or Irinotecan as First Course of Treatment for Patients With Colorectal Cancer That Has Spread Beyond the Colon

Bevacizumab is an angiogenesis inhibitor which means it works to stop blood vessel formation in tumors. Without new blood vessels, the growth of a tumor is slowed. Chemotherapy works to kill cancer cells directly. This study is being done to see how colorectal cancer responds to treatment with the combination of bevacizumab and chemotherapy.