Sorafenib and Anastrozole in Treating Postmenopausal Women With Metastatic Breast Cancer

Inclusion Criteria:

Histologically or cytologically confirmed breast cancer
Metastatic disease

Measurable disease, defined as >=1 unidimensionally measurable lesion, including >= 1 of the following:

Lesion >= 10 mm on CT scan (5 mm sections)
Lesion >= 20 mm on CT scan or MRI (10 mm sections)
Bone disease that is >= 10 mm on MRI
Lytic bone lesions that are >= 10 mm on CT scan (with 5 mm sections) OR >= 20 mm on plain film or CT scan (with 10 mm sections)
Lesion >= 10 mm on physical exam
Patients must have received >= 1 prior aromatase inhibitor in either the adjuvant or metastatic setting and must have had either disease recurrence or disease progression on a prior aromatase inhibitor therapy
No brain metastases diagnosed within the past 6 months OR previously untreated brain metastases
Estrogen receptor-positive and/or progesterone receptor-positive, defined as > 1% staining by immunohistochemistry or > 10 fmol/mg of protein by radio-ligand dextran-coated steroid binding assay

Postmenopausal, as defined by 1 of the following:

Prior bilateral oophorectomy
No menses for >= 12 months in patients with an intact uterus
Follicle-stimulating hormone (FSH) in postmenopausal range in patients < 60 years of age who have had a prior hysterectomy or have been amenorrheic for >= 3 months
Age >= 60 years
Pre- or perimenopausal patients receiving monthly injections of goserelin at a dose of 3.6 mg are eligible
ECOG 0-2
More than 3 months
Absolute neutrophil count >= 1,500/mm3 Platelet count >= 100,000/mm3 No bleeding diathesis
Bilirubin =< 1.5 times upper limit of normal (ULN AST and ALT =< 2.5 times ULN
Systolic blood pressure (BP) < 150 mm Hg and diastolic BP < 100 mm Hg on at least one reading prior to study entry No uncontrolled hypertension

None of the following within the past 6 months:

Symptomatic congestive heart failure
Unstable angina pectoris
Myocardial infarction
Cardiac arrhythmia with hemodynamic compromise
Not pregnant or nursing
Able to swallow oral medication
No known HIV positivity
No ongoing or active infection
No psychiatric illness or social situation that would preclude study compliance
No other active invasive malignancy within the past 5 years except nonmelanoma skin cancer or treated carcinoma in situ of the cervix
No other uncontrolled illness
More than 4 weeks since prior chemotherapy
No more than 2 prior chemotherapy regimens for metastatic disease
At least 8 weeks since prior anastrozole therapy
Concurrent steroids allowed if dose is stable
More than 4 weeks since prior radiotherapy
More than 4 weeks since prior major surgery
Recovered from prior therapy
No prior sorafenib
No concurrent therapeutic anticoagulation
Concurrent prophylactic anticoagulation (i.e., low-dose warfarin) for venous or arterial access devices allowed provided PT and PTT are =< 1.5 times ULN

No concurrent agents that may interact with sorafenib, including any of the following:

Hypericum perforatum (St. John's wort)
Rifampin
P450 CYP3A4 enzyme-inducing anticonvulsants (e.g., phenytoin, carbamazepine, or phenobarbital)
No other concurrent investigational agents

Exclusion Criteria:

estrogen receptor status unknown
history of myocardial infarction within 6 months
performance status 3
performance status 4
premenopausal
progesterone receptor status unknown
HIV positive