ARM II: Patients receive oxaliplatin IV over 2 hours on day 1 and oral capecitabine on days 1-15. Patients are further randomized to receive bevacizumab or placebo* as in arm I. Courses repeat every 3 weeks in the absence of disease progression or unacceptable toxicity. NOTE: *As of 11/15/04, placebo is no longer part of treatment plan; all patients receive bevacizumab.