Comparing Letrozole Given Alone to Letrozole Given With Avastin in Post-Menopausal Women Breast Cancer

Inclusion Criteria:

All patients must meet the following criteria to be eligible for study entry:

* Pathologically confirmed invasive ductal carcinoma or invasive lobular carcinoma of the breast, T2-T3 / T4a-c / N0-2 / M0, with positive estrogen and/or progesterone receptors, and Her-2-neu negative. Patients with inflammatory breast cancer will not be included (T4d). Patients previously treated patients with no measurable disease or patients with metastatic disease will be excluded.
* Give written informed consent prior to study specific screening procedures, with the understanding that the patient has the right to withdraw from the study at any time, without prejudice.
* Patients must be postmenopausal, defined as one of the following:

  * Patients \> 50 years of age with no spontaneous menses for at least 12 months,
  * Bilateral oophorectomy
* Be ambulatory (outpatient) and have an ECOG PS \<1.
* Patients must have measurable disease by mammogram and/or breast ultrasound (in special cases a dedicated breast MRI may be clinically indicated). The target lesion must not have been previously irradiated.
* No prior chemotherapy.
* Patients must have adequate organ and marrow function as defined as follows: absolute neutrophil count \> 1,500/mm3, hemoglobin \> 8.0 g/dl, platelets \> 75,000/mm3, total bilirubin \< 2 mg/dl, serum creatinine \< 2 mg/dl, Transaminases (AST, ALT) may be up to 2 x institutional upper limit of normal. In addition \< 1 gr of protein in 24 hr urine collection and urine protein/creatinine ratio \< 1.0.
* No life threatening parenchymal disease or rapidly progressing disease warranting cytotoxic chemotherapy.
* Hypertension must be controlled (\<150/100 mmHg).
* Ejection Fraction \> 50% by echocardiogram. (LVEF greater than 75% at baseline should be reviewed and/or the test repeated as it may be falsely elevated).
* No history of thrombosis during the previous 12 months.

Exclusion Criteria:

* Current, recent (within 4 weeks of the first infusion of this study), or planned participation in an experimental drug study other than this sponsor-investigator Bevacizumab cancer study.
* Uncontrolled high blood pressure (\>150/100 mmHg).
* Unstable angina
* New York Heart Association (NYHA) Grade III or greater congestive heart failure
* History of myocardial infarction or unstable angina within 12 months
* History of stroke or TIA within 12 months
* Clinically significant peripheral vascular disease
* History of a bleeding disorder
* Presence of central nervous system or brain metastases
* Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to Day 0, anticipation of need for major surgical procedure during the course of the study
* Minor surgical procedures (excluding fine needle aspirations or core biopsies) within 5 days prior to Day 0
* Pregnant (positive pregnancy test) or lactating
* Urine protein: creatinine ratio greater than or equal to 1.0 at screening or patients demonstrating \> 1 gr of protein in 24 hr urine collection within 4 weeks prior to study entry will not participate in the trial.
* History of abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within 6 months prior to Day 0
* Serious, non-healing wound, ulcer, or bone fracture
* Unwilling or unable to comply with the protocol for the duration of the study.
* Psychiatric illness/social situations that would limit compliance with study requirements.
* History of another malignancy within the last five years except non-melanoma skin cancer and carcinoma in-situ of uterine cervix.
* Patients with metastatic disease.