Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of breast cancer

-T2-T4c, any N, M0 disease

- Clinically staged, as documented by the operating surgeon, as 1 of the following:

- T4a-c disease for which modified radical mastectomy with negative margins is the
goal

- T2 or T3 disease for which conversion from needing mastectomy to breast
conservation is the goal

- T2 disease for which lumpectomy at first attempt is the goal

- Primary tumor must be palpable and measure 2 cm by caliper measurements in at least
one dimension

- Must agree to undergo mastectomy or lumpectomy after neoadjuvant aromatase inhibitor
therapy

- No inflammatory breast cancer, defined as clinically significant erythema of the
breast and/or documented dermal lymphatic invasion (not direct skin invasion by tumor
or peau d'orange without erythema)

- No distant metastasis (M1)

-Isolated ipsilateral supraclavicular node involvement allowed

- Must have estrogen receptor (ER) positive tumor with an Allred score of 6, 7 or 8

PATIENT CHARACTERISTICS:

- ECOG/Zubrod performance status of ≤ 2

- Female

- Patient must be postmenopausal, verified by 1 of the following:

- Bilateral surgical oophorectomy

- No spontaneous menses > 1 year

- No menses for < 1 year with FSH and estradiol levels in postmenopausal range

- If patient is a cancer survivor, all of the following criteria must be met:

- Must have undergone potentially curative therapy for all prior malignancies

- No evidence of any prior malignancies for at least 5 years with no evidence of
recurrence (except for successfully treated cervical carcinoma in situ, lobular
carcinoma in situ of the breast, or non-melanoma skin cancer with no evidence of
recurrence)

- Deemed by their treating physician to be at low risk for recurrence

PRIOR CONCURRENT THERAPY:

- Any agent with estrogenic or putatively estrogenic properties, including herbal
preparations, must be stopped at least one week prior to registration

- No prior treatment for breast cancer, including radiation, endocrine therapy,
chemotherapy, or investigational agent

- No concurrent enrollment in another neoadjuvant clinical trial for treatment of the
existing breast cancer

- No hormone replacement therapy of any type, megestrol acetate, or raloxifene within
one week prior to registration

- No other concurrent anti-neoplastic approach such as chemotherapy or radiation
therapy

- Concomitant use of agents and herbal products that alter ER function are specifically
not allowed