Exemestane, Letrozole, or Anastrozole in Treating Postmenopausal Women Who Are Undergoing Surgery for Stage II or Stage III Breast Cancer

DISEASE CHARACTERISTICS:

* Diagnosis of breast cancer

  * T2-T4c, any N, M0 disease
* Clinically staged, as documented by the treating physician, 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 tape, ruler, or 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
* No diagnosis that was established by incisional biopsy
* Must have estrogen receptor (ER) positive tumor with an Allred score of 6, 7 or 8

  * Patients with \> 66.66% (two-thirds) of cells staining positive and have a minimum Allred score of 6 are eligible

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
* No other malignancies within the past 5 years, except for successfully treated cervical carcinoma in situ; lobular carcinoma in situ of the breast; contralateral ductal carcinoma in situ that was treated with mastectomy or lumpectomy with radiotherapy (without tamoxifen); or non-melanoma skin cancer with no evidence of recurrence

  * Must have undergone potentially curative therapy for all prior malignancies AND deemed to be at low risk for recurrence, according to the treating physician

PRIOR CONCURRENT THERAPY:

* No prior treatment for invasive breast cancer, including radiotherapy, endocrine therapy, chemotherapy, or investigational agents
* No prior sentinel lymph node biopsy (cohort B only)
* At least 1 week since prior agents with estrogenic or putatively estrogenic properties, including herbal preparations
* At least 1 week since prior hormone replacement therapy of any type, megestrol acetate, or raloxifene
* No concurrent enrollment in another neoadjuvant clinical trial for treatment of the existing breast cancer
* No other concurrent anti-neoplastic therapy, including chemotherapy or radiotherapy
* No concurrent agents or herbal products that alter ER function