Purpose

This randomized phase III trial studies octreotide acetate and recombinant interferon alfa-2b to see how well it works compared to octreotide acetate and bevacizumab in treating patients with high-risk neuroendocrine tumors that have spread to other places in the body (metastatic) or spread from where it started to nearby tissue or lymph nodes (locally advanced). Octreotide acetate and recombinant interferon alfa-2b may interfere with the growth of tumor cells and slow the growth of cancer. Monoclonal antibodies, such as bevacizumab, may interfere with the ability of tumor cells to grow and spread. It is not yet known whether giving octreotide acetate together with recombinant interferon alfa-2b is more effective than giving octreotide acetate together with bevacizumab in treating patients with neuroendocrine tumor.