This phase II trial is studying how well sorafenib works in treating patients with soft tissue sarcoma. Sorafenib may stop the growth of soft tissue sarcoma by blocking blood flow to the tumor and blocking some of the enzymes needed for tumor cell growth

PRIMARY OBJECTIVES: I. To determine if the combined vascular endothelial growth factor receptor 2 (VEGF-R2)/platelet-derived growth factor receptor (PDGFR)-beta inhibitor BAY 43-9006/ sorafenib can decrease interstitial fluid pressure (IFP) in soft tissue sarcomas. II. To investigate the effects of BAY 43-9006/sorafenib on tumor blood flow, circulating endothelial cells, vascular density and pericyte coverage. III. To characterize the pharmacokinetics of BAY 43-9006/sorafenib in sarcoma patients. SECONDARY OBJECTIVES: I. To describe any preliminary evidence of anti-tumor activity. II. Assess whether there are any significant relationships between systemic drug exposure and drug-related toxicity or biological effect. OUTLINE: This is a multicenter study. Patients are assigned to one of two groups (group 1 closed to accrual as of 5/30/07). GROUP I (SARCOMAS OF THE EXTREMITY) (CLOSED TO ACCRUAL AS OF 5/30/07): Patients receive oral sorafenib twice daily on days 1-14. Patients undergo surgical resection of the tumor on approximately day 15. Once patients recover from surgery (and radiotherapy if indicated), patients who demonstrate a clinically and pathologically significant response (≥ 25% reduction in tumor size or ≥ 25% necrosis in the surgical specimen) may continue sorafenib as above for a maximum of 6 months in the absence of disease progression or unacceptable toxicity and at the discretion of the principal investigator. Biopsy tissue and blood samples are examined for biomarkers and interstitial fluid pressure (IFP) is measured at baseline and immediately before surgery. GROUP II (METASTATIC OR INOPERABLE SARCOMAS): Patients receive oral sorafenib twice daily on days 1-28. Treatment repeats every 28 days for 2 courses. Patients with responding or stable disease may continue sorafenib in the absence of disease progression or unacceptable toxicity. Biopsy tissue and blood samples are examined for biomarkers and IFP is measured at baseline and on days 28 and 56. In both groups, blood samples are drawn periodically for pharmacological studies. After completion of study therapy, patients are followed monthly until all study-related toxicities are resolved and then at the discretion of the investigator.