All eligible patients will receive 800 mg of pazopanib orally each day continuously. Patients will be re-evaluated for treatment response after 8 weeks of daily oral pazopanib therapy. Response to therapy will be assigned using RECIST criteria (Section 6.0) Patients who have objective response or stable disease will continue treatment with evaluations every 8 weeks, until the time of tumor progression or intolerable treatment-related side effects.