Dasatinib in Combination With Bevacizumab to Treat Advanced Solid Tumors

Background: * Bevacizumab inhibits blood vessel growth in cancer cells by blocking a growth factor called VEGF. Dasatinib inhibits the action of proteins called tyrosine kinases, which promote and stimulate blood vessel formation and cancer growth and spread. * Using the two drugs in combination may provide a more effective cancer treatment than either drug used alone. * Both drugs have been approved by the Food and Drug Administration for different cancer types, but their use in combination sis experimental. Objectives: \- To determine the highest doses of the combination of dasatinib and bevacizumab that can be safely given to patients with different cancers and to find out what effects, good and bad, these drugs may have on the patient and the disease. Eligibility: \- Adult patients with an advanced solid tumor cancer that cannot be treated successfully with standard therapies. Design: * Patients in Group 1 receive dasatinib and bevacizumab together throughout the study. The dose is increased in successive groups of three to six patients until the optimum safe dose is determined. Patients take dasatinib by mouth once a day and receive bevacizumab as an infusion through a vein once every 2 weeks in 28-day treatment cycles. * Patients in Group 2 are randomly assigned to receive either dasatinib or bevacizumab for cycle one, and then both drugs for all subsequent cycles. The drug doses are based on the optimum doses found in Group 1 patients. * Patients have a physical examination and blood and urine tests every 2 weeks for cycles 1 and 2, and then every 4 weeks for the duration of treatment. * Patients have CT or MRI scans or another imaging test such as ultrasound every 8 weeks to monitor the cancer s response to treatment. * Tumor biopsies are obtained from patients in Group 2 before treatment, 2 weeks into the first treatment cycle, and 2 weeks into the second cycle. * Dynamic, contrast-enhanced MRI (DCE-MRI) tests are done on patients in Group 2 before t