Sorafenib and Fulvestrant in Treating Patients With Locally Advanced or Metastatic Breast Cancer That Did Not Respond to Aromatase Inhibitor Therapy

DISEASE CHARACTERISTICS:

* Diagnosis of incurable breast cancer

  * Locally advanced or metastatic disease
* Measurable or evaluable disease

  * Measurable disease is defined as ≥ 1 uni-dimensionally measurable lesion ≥ 20 mm by conventional techniques or ≥ 10 mm by spiral computed tomography(CT) scan

    * Bone-only metastases that can be imaged with bone scan AND magnetic resonance imaging (MRI) or bone scan AND plain x-ray is considered measurable disease
    * Tumor lesions that are situated in a previously irradiated area are considered measurable only if they are progressing at the time of study entry
  * Evaluable disease includes unresectable skin/chest wall metastases that can be photographed and whose size can be measured with a ruler

    * Bone-only metastases that can only be imaged using bone scan or malignant pleural effusion(s) only are not considered evaluable disease
* Previously treated with a third-generation aromatase inhibitor (e.g., letrozole, anastrazole, or exemestane) AND meets one of the following criteria:

  * Progressed during palliative aromatase inhibitor therapy
  * Recurred during adjuvant aromatase inhibitor therapy
  * Recurred within 12 months of completing adjuvant aromatase inhibitor therapy
* Human Epidermal growth factor Receptor 2(HER2/neu)-negative tumor

  * No Human Epidermal growth factor Receptor 2(HER2/neu) overexpression (i.e., tumor staining 3+ by immunohistochemistry \[IHC\] or gene amplified by Fluorescence In Situ Hybridization \[FISH\])
* Hormone receptor status:

  * Estrogen receptor and/or progesterone receptor positive, defined as ≥ 10% of malignant cells with positive nuclear staining

PATIENT CHARACTERISTICS:

* Postmenopausal
* Eastern Cooperative Group(ECOG) performance status 0-1
* Life expectancy ≥ 16 weeks
* Neutrophil count ≥ 1,500/mm\^³
* Platelet count ≥ 100,000/mm\^³
* Hemoglobin ≥ 9.0 g/dL
* Creatinine \< 2 mg/dL
* Total bilirubin ≤ 1.5 times upper limit of normal (ULN)
* Alanine aminotransferase (ALT) and aspartate aminotransferase(AST) ≤ 2.5 times ULN (≤ 5 times ULN for patients with liver involvement)
* International Normalized Ratio(INR) \< 1.5 OR Prothrombin time/ partial thromboplastin time (PT/PTT) normal
* Left ventricular ejection fraction(LVEF) normal by Multiple Gated Acquisition(MUGA) or ECHO
* No known allergy to sorafenib tosylate or fulvestrant
* No cardiac disease, including any of the following:

  * New York Heart Association(NYHA) class III-IV congestive heart failure
  * Unstable angina (anginal symptoms at rest) or new-onset angina (within the past 3 months)
  * Myocardial infarction within the past 6 months
  * Cardiac ventricular arrhythmias requiring anti-arrhythmic therapy
* No uncontrolled hypertension, defined as systolic blood pressure \> 150 mm Hg or diastolic blood pressure \> 90 mm Hg despite optimal medical management
* No thrombotic or embolic events, such as cerebrovascular accident (including transient ischemic attacks), within the past 6 months
* No known HIV infection or chronic hepatitis B or C infection
* No infection that requires IV antibiotics or produces a fever \> 100°F within the past 72 hours
* No pulmonary hemorrhage/bleeding event ≥ Common terminology criteria for adverse events(CTCAE) grade 2 within the past 4 weeks
* No other hemorrhage/bleeding event ≥ CTCAE grade 3 within the past 4 weeks
* No evidence or history of bleeding diathesis or coagulopathy
* No significant traumatic injury within the past 2 weeks
* No serious, nonhealing wound, ulcer, or bone fracture
* No condition that impairs the patient's ability to swallow whole pills
* No malabsorption problem
* No second malignancy within the past 5 years, except adequately treated and cured basal cell or squamous cell skin cancer or carcinoma in situ of the cervix
* No underlying medical condition that, in the principal investigator's opinion, will make the administration of study drug hazardous or would obscure the interpretation of adverse events

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No prior chemotherapy for metastatic or unresectable locally advanced breast cancer
* No prior sorafenib tosylate or other Vascular endothelial growth factor(VEGF)-targeting therapies
* More than 2 weeks since prior major surgery or open biopsy
* No concurrent anticoagulation with warfarin or heparin
* No concurrent Hypericum perforatum (St. John wort) or rifampin
* No other concurrent anticancer agents, including chemotherapy or biological therapy
* No other concurrent investigational drugs
* Concurrent bisphosphonates allowed