Bevacizumab Treatment for Solid Tumors, February 2, 2011, Hayes 305 (5): 506 — JAMA
Avastin is a really expensive (think 50K a year) and dangerous (people die more often) drug that has been shown to have marginal positive effects on the progression of cancer for some patients. It is a very difficult question to weigh up efficacy, safety and cost for a drug of such extremes.
JAMA published a meta-analysis demonstrating the danger of the drug, and follow up with an opinion piece (linked above) that attempts to reconcile the issues to reach a conclusion. I think that enough noise has been made for that conclusion to be quite clear.