Inclusion Criteria:- Patients must have a histologically confirmed, bi-dimensionally measurable, recurrent or metastatic carcinoma of the breast that is progressive.

• All patients must be female and premenopausal. Premenopausal is defined as either: (1) last menstrual period within 3 months, or (2) post-hysterectomy without bilateral oophorectomy and with FSH in the premenopausal range, or, (3) if on tamoxifen within the past 3 months, a plasma estradiol in the premenopausal range.
• Patients must have either positive estrogen and/or progesterone receptor determination by IHC or competitive binding assay on metastatic disease, or if not performed on their metastatic disease a positive result on their primary breast cancer specimen.
• No prior treatment with an aromatase inhibitor or inactivator.
• No prior treatment with an LH/RH agonist/antagonist.
• No adjuvant chemotherapy within 6 months of study entry.
• Patients must have an ECOG performance status of 0, 1, or 2.

• Patients must have adequate bone marrow, hepatic, and renal function defined by the following:

  • Granulocytes > 1500/mm^3
  • Platelets > 100,000/mm^3
  • SGOT < 2.5x upper limit of normal
  • Total bilirubin < 1.5 mg/dL
• Patients with central nervous system metastasis or lymphangitic pulmonary metastasis are not eligible.
• Patients must not have received chemotherapy or hormonal therapy for at least 3 weeks prior to enrollment.
• Patients may receive irradiation to bony sites of disease for pain control or for prevention of fracture, but the irradiated site(s) will NOT be considered evaluable for disease response.
• Patients who are pregnant or lactating are ineligible. Must be using effective contraception or not be of childbearing potential.
• Patients must not have had an active malignancy other than breast cancer, in situ carcinoma of the cervix, or non-melanomatous skin cancers in the past 5 years.
• No active, unresolved infection.
• All patients must give signed written informed consent.