Bevacizumab With or Without Cyclophosphamide and Methotrexate: A Pilot Study in Women With Operable Breast Cancer

Inclusion Criteria: * Histologically or cytologically confirmed invasive breast cancer, preoperative stages II-III per AJCC 6th edition, based on baseline evaluation by clinical examination and/or breast imaging * Patients must have completed preoperative (neoadjuvant) chemotherapy with a standard chemotherapy regimen. No more chemotherapy should be planned. * Patients must have completed definitive resection of primary tumor with adequate excision of gross disease. * For patients receiving adjuvant radiation therapy, treatment must be completed prior to initiation of protocol therapy. * Patients must have the presence of significant residual invasive disease on pathologic review following their preoperative chemotherapy. * LVEF \> institutional limits of normal after preoperative chemotherapy, as assessed by ECHO or nuclear medicine gated study, within 30 days prior to initiating protocol-based treatment. * ECOG performance status 0-1 Exclusion Criteria: * Inadequate organ function, as measured by laboratory assessment after preoperative chemotherapy and within 14 days of beginning protocol-based treatment * Patients with metastatic disease are ineligible. * Known HIV infection * Patients may not be pregnant, expect to become pregnant, plan to conceive a child while on study, or breastfeeding * Uncontrolled intercurrent illness * Non-healing wounds or major surgical procedures (such as breast surgery) other than that for venous access device or diagnostic study are not permitted within 28 day prior to enrollment * History of abdominal fistula, GI perforation, intra-abdominal abscess, or serious, non-healing wound, ulcer, or bone fracture within 6 months prior to initiating bevacizumab * Patients with any history of arterial thromboembolic events, including transient ischemic attack (TIA), cerebrovascular event (CVA), unstable angina, or myocardial infarction (MI) within the past 6 months. Patients with clinically significant peripheral arterial disease should also be excluded * History of bleeding diathesis or coagulopathy * History of grade 3 or 4 allergic reactions to compounds of similar chemical or biologic composition to cyclophosphamide (such as other alkylating agents) or methotrexate (such as other antimetabolites) * Prior history of malignancy treated without curative intent, excluding nonmelanomatous skin cancer * Patients with large or rapidly accumulating pleural or abdominal effusions * Current use of anticoagulants is allowed as long as patients have been on a stable dose for more than two weeks with stable INR * Chronic therapy with full dose aspirin (\< 325 mg/day) or standard non-steroidal anti-inflammatory agents is allowed * Patients may not receive other investigational agents while on study