Study of Avastin (Bevacizumab) to Reverse Acquired Estrogen Independence in Previously Hormone Responsive Metastatic Breast Ca.

All patients will received Avastin 15 mg/kg IV every three weeks. The first evaluation will be done at Week 6. Patients with objective response or stable disease will continue therapy with restaging every 6 weeks until evidence of disease progression. Patients with progression of disease will be taken off study.

aromatase inhibitor (letrozole 2.5mg/d PO, anastrazole 1mg/d PO, or exemestane 25mg/d PO)or Selective Estrogen Receptor Modulator (SERM) (tamoxifen 20mg/d PO)