DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed breast cancer

  • Recurrent locally advanced disease not amenable to local therapy (i.e., surgery and radiotherapy)
  • Metastatic disease

• Either the primary or metastatic tumor must meet ≥ 1 of the following criteria:

  • Estrogen receptor positive (≥ 1% by immunohistochemical staining)
  • Progesterone receptor positive (≥ 1% by immunohistochemical staining)
  • HER2/neu overexpression (3+ by immunohistochemical staining or positive by fluorescent in situ hybridization [FISH])
• Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan
• Tissue samples available for correlative studies

• Brain metastases allowed provided all of the following criteria are met:

  • Controlled by prior surgery or radiotherapy
  • Neurologically stable and off steroids for ≥ 4 weeks

PATIENT CHARACTERISTICS:

• ECOG performance status 0-1
• Male or female
• Menopausal status not specified
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Bilirubin normal
• AST/ALT ≤ 3 times upper limit of normal (ULN)
• Creatinine ≤ 2.0 times ULN
• Cholesterol ≤ 350 mg/dL (fasting)
• Triglycerides ≤ 400 mg/dL (fasting)
• Albumin ≥ 3.3 mg/dL
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier-method contraception

• No uncontrolled illness, including, but not limited to, any of the following:

  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Uncontrolled symptomatic cardiac arrhythmia
  • Psychiatric illness or social situation that would preclude compliance with study requirements
• No known hypersensitivity to macrolide antibiotics (e.g., erythromycin, clarithromycin, or azithromycin)

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from prior therapy
• No prior rapamycin or any other mTOR inhibitor
• At least 1 week since prior hormonal agents, except for premenopausal women receiving a gonadotropin-releasing hormone (GnRH) agonist with subsequent progression*
• At least 3 weeks since prior chemotherapy
• At least 3 weeks since prior monoclonal antibody therapy
• No concurrent radiotherapy
• No concurrent herbal preparations
• No concurrent corticosteroids except low-dose corticosteroids as replacement for adrenal insufficiency or for short-term (< 5 days) use
• No concurrent enzyme-inducing antiepileptic drugs (e.g., phenytoin, carbamazepine, or phenobarbital)
• No other concurrent CYP3A4 inducers (e.g., rifampin or Hypericum perforatum [St. John's wort])
• No concurrent prophylactic hematopoietic colony-stimulating factors
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent anticancer agents or therapies
• No other concurrent investigational agents NOTE: *Concurrent GnRH agonists allowed for these patients at the discretion of the principal investigator