Aromatase Inhibitor Clinical Trial

Inclusion Criteria:

1. Female gender.
2. Post-menopausal status, defined as:

   * age \> 60; or
   * less than age 60 and the last menstrual period \>12 months prior to enrollment in trial if intact uterus/ovaries; or,
   * less than age 60 and the last menstrual period 6-12 months prior to enrollment in trial if intact uterus/ovaries and meets biochemical criteria for menopause (FSH and estradiol levels within institutional standards for menopausal status) NOTE: These subjects will have serum estradiol levels checked at visits 0, 1, 3, 6 and 12 months to check for continued menopausal status; or,
   * less than age 60 and history of bilateral oophorectomy; or,
   * less than age 60 and has a history of hysterectomy and meets biochemical criteria for menopause (FSH and estradiol levels within institutional standards for menopausal status).

   NOTE: These subjects will have serum estradiol levels checked at visits 0, 1, 3, 6 and 12 months to check for continued menopausal status; or,
   * less than age 60 and taking medication designed to suppress ovarian function and meets biochemical criteria for menopause (estradiol levels within institutional standards for menopausal status). Women would have had to be taking the drug for at least 30 days prior to entering the study.

   NOTE: While the patient is being treated with a GnRh agonist (luprolide or goserelin), serum estradiol levels will be checked at visits 0, 1, 3, 6 and 12 months to check for menopausal status.
3. Patients with histologically proven ductal carcinoma in situ (DCIS/stage 0) or stage I-III invasive carcinoma of the breast that is ER and/or PR positive by immunohistochemical staining, who are considering aromatase inhibitor therapy. Patients must have completed any adjuvant chemotherapy. Patients may have received preoperative chemotherapy. Patients should have also completed local therapy; however, enrollment/initiation of aromatase inhibitor on study may be done prior to completion of radiation therapy. Women may receive the aromatase inhibitor on this study as initial adjuvant hormonal treatment or following adjuvant tamoxifen.
4. ECOG performance status 0-2.
5. The patient is aware of the nature of her diagnosis, understands the study regimen, its requirements, risks, and discomforts, and is able and willing to sign an informed consent form.

Exclusion Criteria:

1. History of bilateral mastectomy.
2. History of radiation to the contralateral breast.
3. Prior use of an aromatase inhibitor.
4. Personal history of the following cancers: ovarian, endometrial, fallopian tube and primary peritoneal carcinomatosis.
5. Presence of implant in contra-lateral breast.
6. Women with history of breast reduction should be entered at the discretion of the investigator. Breast reduction during the two years of the trial is strongly discouraged.