Inclusion Criteria:

- No prior sorafenib

- Histologically or cytologically confirmed uterine carcinoma or carcinosarcoma:

- Advanced or recurrent disease

- Not amenable to curative surgery or radiotherapy

- Measurable disease:

- At least 1 unidimensionally measurable lesion >= 20 mm by conventional
techniques OR >= 10 mm by spiral CT scan

- Tumor tissue block must be available

- No known brain metastases

- Performance status:

- ECOG 0-2 OR

- Karnofsky 60-100%

- Hematopoietic:

- Absolute neutrophil count >= 1,500/mm3

- Platelet count >= 100,000/mm3

- No bleeding diathesis

- Hepatic:

- Bilirubin normal

- AST and ALT =< 2.5 times upper limit of normal

- Renal:

- Creatinine =< 1.5 mg/dL OR

- Creatinine clearance >= 60 mL/min

- Cardiovascular:

- No uncontrolled hypertension, defined by 1 of the following:

- Blood pressure > 150/100 mm Hg

- Currently taking > 1 antihypertensive agent

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No other active malignancy

- No history of allergic reactions attributed to compounds of similar chemical or
biological composition to sorafenib

- No ongoing or active infection

- No psychiatric illness or social situation that would preclude study compliance

- No swallowing dysfunction that would preclude study drug ingestion

- No other uncontrolled illness

- Prior biological response modifier therapy allowed

- No prior antiangiogenesis therapy

- No prior MAPK-signaling agents

- No prior vascular endothelial growth factor receptor (VEGFR) inhibitors

- No more than 1 prior chemotherapy regimen

- More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)

- Prior hormonal therapy allowed

- Prior radiotherapy allowed provided the only site of measurable disease was not
located within the radiation port OR disease has progressed since completion of
therapy

- Recovered from all prior therapy

- Concurrent warfarin allowed provided all of the following are true:

- Patient is therapeutic on a stable warfarin dose

- INR target range =< 3

- Patient is monitored with weekly INR testing

- No active bleeding or pathological condition that carries a high bleeding risk

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No concurrent cytochrome P450 enzyme-inducing antiepileptic drugs (e.g., phenytoin,
carbamazepine, or phenobarbital)

- No concurrent rifampin

- No concurrent Hypericum perforatum (St. John's wort)

- No other concurrent investigational agents

- No other concurrent anticancer therapy

- More than 4 weeks since prior radiotherapy