DISEASE CHARACTERISTICS:

• Histologically confirmed invasive mammary carcinoma

  • Stage IV disease
• No locally recurrent breast cancer
• Patients with HER2/neu overexpressing tumors must have received prior trastuzumab (Herceptin®) in first-line treatment of metastatic breast cancer
• Patients with estrogen receptor- or progesterone receptor-expressing tumors must have received prior endocrine therapy (i.e., aromatase inhibitors, fulvestrant, tamoxifen, or ovarian ablation) in first-line treatment of metastatic breast cancer

• No symptomatic brain metastases

  • Patients with a history of brain metastases must be clinically stable and not taking steroids or therapeutic anticonvulsants that are CYP3A4 modifiers
  • Patients with asymptomatic brain metastases on prophylactic convulsants that are CYP3A4 modifiers are not eligible
• Hormone receptor status not specified

PATIENT CHARACTERISTICS:

• Menopausal status not specified
• ECOG performance status 0-1
• Life expectancy ≥ 6 months
• ANC ≥ 1000/mm^3
• Platelet count ≥ 100,000/mm^3
• Creatinine ≤ 1.5 times upper limit of normal (ULN)
• Bilirubin ≤ 1.5 times ULN (3 times ULN if liver metastasis present)
• SGOT and SGPT ≤ 1.5 times ULN (3 times ULN if liver metastasis present)
• Alkaline phosphatase ≤ 3 times ULN if liver metastasis present
• Able to swallow and retain oral medication
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after completion of study treatment
• Must be disease-free from prior invasive cancers for > 5 years with the exception of completely resected basal cell or squamous cell carcinoma of the skin or successfully treated cervical carcinoma in situ
• No malabsorption syndrome, disease significantly affecting gastrointestinal function, or ulcerative colitis

• No uncontrolled intercurrent illness including, but not limited to:

  • Ongoing or active infection requiring parenteral antibiotics
  • Impairment of lung function (i.e., chronic obstructive pulmonary disease or lung conditions requiring oxygen therapy)
  • Symptomatic New York Heart Association class III-IV congestive heart failure
  • Unstable angina pectoris, angioplasty, stenting, or myocardial infarction within the past 6 months
  • Uncontrolled hypertension (systolic blood pressure [BP] > 180 mm Hg or diastolic BP > 100 mm Hg)
  • Clinically significant cardiac arrhythmia (i.e., multifocal premature ventricular contractions, bigeminy, trigeminy, or ventricular tachycardia that is symptomatic or requires treatment)
  • Uncontrolled diabetes
  • Psychiatric illness/social situations that would preclude compliance with study requirements
• No known history of uncontrolled or symptomatic neuropathy ≥ grade 2
• No hypersensitivity to paclitaxel, or drugs using the vehicle Cremophor, Chinese hamster ovary cell products, or other recombinant human antibodies

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from all prior treatment
• Must not have exceeded a total cumulative dose of life-time exposure of doxorubicin hydrochloride ≤ 360 mg/m² or epirubicin hydrochloride ≤ 640 mg/m²
• At least 2 weeks since other prior investigational drugs
• No prior resection of the stomach or small bowel

• No more than 4 prior chemotherapy regimens in the metastatic setting

  • This restriction does not include endocrine therapies or single agent biologic therapies (i.e., trastuzumab)
• Concurrent radiotherapy to painful bone metastases or areas of impending bone fracture allowed as long as radiotherapy is initiated prior to study entry
• No concurrent trastuzumab
• No concurrent endocrine therapy
• No concurrent CYP3A4 modifiers
• No concurrent herbal supplement
• No other concurrent anticancer therapy (chemotherapy, radiotherapy, surgery, immunotherapy, hormonal therapy, or biological therapy)