Gemcitabine and Bevacizumab in Treating Patients With Pancreatic Cancer That Has Been Completely Removed By Surgery

RATIONALE: Drugs used in chemotherapy, such as gemcitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Bevacizumab may also stop the growth of pancreatic cancer by blocking blood flow to the tumor. Giving gemcitabine and bevacizumab after surgery may kill any tumor cells that remain after surgery. PURPOSE: This phase I/II trial is studying the side effects of gemcitabine and bevacizumab and to see how well they work in treating patients with pancreatic cancer that has been completely removed by surgery.