Phase II Study of Sunitinib Malate for Metastatic and/or Surgically Unresectable Soft Tissue Sarcoma

Inclusion Criteria: * Resolution of all acute toxic effects of prior chemotherapy or radiotherapy or surgical procedures to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) Version 3.0 grade less than or equal to 1. * Adequate organ function as defined by the following criteria: * Serum aspartate transaminase (AST) and serum alanine transaminase (ALT) less than or equal to 2.5 x local laboratory upper limit of normal (ULN), or AST and ALT less than or equal to 5 x ULN if liver function abnormalities are due to underlying malignancy * Total serum bilirubin less than or equal to 1.5 x ULN * Absolute neutrophil count (ANC) greater than or equal to1500/microL * Platelets greater than or equal to 100,000/microL * Hemoglobin greater than or equal to 9.0 g/dL * Serum calcium less than or equal to 12.0 mg/dL * Serum creatinine less than or equal to 1.5 x ULN * Histologically-proven liposarcoma, leiomyosarcoma, fibrosarcoma, or MFH * Measurable disease radiographically * Disease that is deemed surgically unresectable and/or metastatic * Age greater than or equal to 18 years * Life expectancy greater than 16 weeks * Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2 * Patients may have had up to 3 prior chemotherapies within 4 weeks of starting the study treatment. Exclusion Criteria: * Major surgery or radiation therapy or chemotherapy within 4 weeks of starting the study treatment. * NCI CTCAE version 3 grade 3 hemorrhage within 4 weeks of starting the study treatment. * History of or known brain metastases, spinal cord compression, or carcinomatous meningitis, or evidence of symptomatic brain or leptomeningeal disease. * Any of the following within the 6 months prior to study drug administration: * myocardial infarction, * severe/unstable angina, * coronary/peripheral artery bypass graft, * symptomatic congestive heart failure, * cerebrovascular accident or transient ischemic attack, or pulmonary embolism * Ongoing cardiac dysrhythmias of NCI CTCAE greater than or equal to grade 2 * Prolonged QTc interval on baseline electrocardiogram (ECG) \> 500 msec. * Hypertension that cannot be controlled by medications (\>150/100 mm Hg despite optimal medical therapy) * Prior tyrosine kinase inhibitor therapy * Pre-existing thyroid abnormality with thyroid function that cannot be maintained in the normal range with medication * Known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-related illness or other active infection * Concurrent treatment on another clinical trial, except supportive care or non-treatment trials * Concomitant use of agents known to induce or inhibit CYP3A4 * Concomitant use of agents metabolized by the cytochrome P450 system * Ongoing treatment with therapeutic doses of Coumadin (low dose Coumadin up to 2 mg by mouth \[PO\] daily for thrombo-prophylaxis is allowed) * Pregnancy or breastfeeding patients * Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or study drug administration, or may interfere with the interpretation of study results, and in the judgment of the investigator would make the subject inappropriate for entry into this study.