RATIONALE: Vandetanib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Monoclonal antibodies, such as bevacizumab, can block cancer growth in different ways. Some block the ability of cancer cells to grow and spread. Others find cancer cells and help kill them or carry cancer-killing substances to them. Bevacizumab and vandetanib may also stop the growth of cancer cells by blocking blood flow to the cancer. Giving vandetanib together with bevacizumab may kill more cancer cells.