Eligibility Post-menopausal women with receptor positive or unknown receptor status breast cancer who have completed at least 5 years of adjuvant therapy with tamoxifen and are free of disease will be studied. The eligibility criteria for this study have been carefully considered. Eligibility criteria are standards used to assure that patients who enter this study are medically appropriate candidates for this therapy. For the safety of the patients, as well as to ensure that the results of this study can be useful for making treatment decisions regarding other patients with similar diseases, it is important that no exceptions be made to these criteria for admission to the study.
Axillary lymph node negative or positive or unknown at the time of original diagnosis.
Radiologic investigations must be negative for metastases. Timing within 30 days prior to randomization. A confirmatory x-ray is required if the results from the bone scan are questionable. Must be randomized within 3 months of tamoxifen discontinuation. The minimum period of amenorrhea should be 1 year or more.