previous systemic treatment for advanced disease;

radiotherapy to any site within 4 weeks before study;

daily aspirin (\>325 mg/day), anticoagulants, or other medications known to predispose to gastrointestinal ulceration;

co-existing malignancies or malignancies diagnosed within last 5 years (except basal cell cancer or cervical cancer in situ).

A Study of Avastin (Bevacizumab) in Combination Chemotherapy in Patients With Metastatic Cancer of the Colon or Rectum