Sorafenib Tosylate in Treating Patients With Progressive Metastatic Neuroendocrine Tumors

Criteria: * Histologically confirmed neuroendocrine tumor: * Carcinoid tumor OR islet cell carcinoma/other well-differentiated tumor * No anaplastic or high-grade histology * Metastatic disease * Measurable disease * No thyroid carcinoma of any histology, thymoma, or pheochromocytoma/paraganglioma * No known brain metastases * Performance status: * Eastern Cooperative Oncology Group (ECOG) 0-2 * Life expectancy: * At least 24 weeks * Hematopoietic: * Absolute neutrophil count \>= 1,500/mm3 * Platelet count \>= 100,000/mm3 * No bleeding diathesis * Hepatic: * Bilirubin =\< 2 times upper limit of normal (ULN) * Aspartate aminotransferase (AST) =\< 3 times ULN (5 times ULN if liver metastases are present) * International normalized ratio (INR) normal * PTT normal * Renal: * Creatinine =\< 1.5 times ULN * Cardiovascular: No poorly controlled hypertension; No symptoms of congestive heart failure; No unstable angina pectoris; No cardiac arrhythmia * Gastrointestinal: * Able to swallow capsules intact * No gastrointestinal tract disease resulting in an inability to take oral medication (e.g., dysphagia) * No requirement for IV alimentation * No active peptic ulcer disease * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No ongoing or active infection * No psychiatric illness or social situation that would preclude study compliance * No other invasive malignancy within the past 3 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix * No other uncontrolled illness * At least 4 weeks since prior interferon * No more than 1 prior systemic chemotherapy regimen: Chemoembolization is not considered systemic chemotherapy * At least 4 weeks since prior chemoembolization * At least 3 weeks since prior radiotherapy * No prior procedures adversely affecting intestinal absorption * At least 4 weeks since prior hepatic artery embolization * No other prior systemic therapy * No other concurrent investigational treatment * No concurrent combination antiretroviral therapy for HIV-positive patients * No concurrent enzyme-inducing anticonvulsants (e.g., carbamazepine, phenobarbital, or phenytoin) * No concurrent rifampin * No concurrent Hypericum perforatum (St. John's wort) * Prior or concurrent octreotide for symptomatic treatment allowed * No concurrent therapeutic anticoagulation: Concurrent prophylactic anticoagulation (i.e., low dose warfarin) of venous or arterial access devices allowed provided requirements for INR or PTT are met * At least 4 weeks since prior major surgery * Recovered from all prior therapy