- Prior Therapy: Patients must not have received prior chemotherapy in the metastatic breast setting. Patients who have not received prior anthracyclines or taxanes should be considered for these agents. Patients may have received prior chemotherapy and/or hormonal therapy for early stage breast cancer. The chemotherapy regimen may have included an anthracycline and/or a taxane as long as it has been > 6 months since completion of the regimen. Adjuvant trastuzumab is allowed. Patients may have received prior radiation therapy in either the metastatic or early stage setting as long as <25% of the bone marrow has been treated. Prior radiation to the whole pelvis is not allowed. Radiation therapy must be completed at least 7 days prior to study registration, and all radiation related toxicities must be resolved to grade ≤ 1 before patient is eligible for study inclusion. Patients may have received any number of hormonal therapies in the neo-adjuvant, adjuvant or metastatic setting.