A Study of Avastin (Bevacizumab) in Combination With mFOLFOX-6 or FOLFOXIRI in Patients With Metastatic Colorectal Cancer.

This 2 arm study will compare the resection rate of liver metastases and safety of surgery in patients with metastatic colorectal cancer and primarily unresectable liver metastases receiving treatment with Avastin in combination with 5-FU, leucovorin and oxaliplatin with irinotecan (FOLFOXIRI) or without irinotecan (mFOLFOX-6) as first line treatment. Patients will be randomized to receive Avastin (5mg/kg iv every 2 weeks) in combination with each of these two standard neoadjuvant chemotherapy regimens. The anticipated time on study treatment is until surgery, disease progression, unacceptable toxicity or patient refusal, and the target sample size is <100 individuals.