Letrozole or Tamoxifen in Treating Postmenopausal Women With Breast Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed resectable adenocarcinoma of the breast
• * pT1, pT2, pT3, or minimal dermal involvement on pathology only
• * pN0, pN1, pN2, or M0
• * Negative nodal status
• * At least 8 nodes are negative
• * Unknown nodal status
• * Less than 8 nodes examined and no pathological finding
• * Positive nodal status
• * Any positive finding independent of the number of nodes examined
• * Negative sentinel node or no prior nodal dissection allowed if all other criteria met
• Must have had total mastectomy, lumpectomy, or quadrantectomy
• * Should have prior chest wall radiotherapy after segmental mastectomy or histopathologic T4 dermal involvement
• Stage I, II, or IIIa allowed if the tumor is completely removed macroscopically and margins of the resected tumor are microscopically free of tumor
• Must undergo chest wall radiotherapy or second resection if microscopic disease at the mastectomy margins
• No bilateral disease except in situ disease, either ductal or lobular of the contralateral breast
• Postmenopausal
• * Regardless of prior hormonal replacement therapy (HRT) or hysterectomy:
• * Bilateral oophorectomy and any age
• * Radiologic castration and amenorrheic for at least 3 months and any age
• * Not postmenopausal at the start of adjuvant chemotherapy AND and completed at least 6 courses of prior cyclophosphamide, methotrexate, and fluorouracil (CMF) or at least 4 courses of prior anthracycline-cyclophosphamide continuation therapy and at least age 45 with follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) postmenopausal levels
• * No prior HRT:
• * Prior hysterectomy and less than age 55 with FSH/LH/E2 postmenopausal levels
• * Prior hysterectomy and at least age 55
• * No prior HRT or hysterectomy:
• * Amenorrhea more than 1 year and less than age 50
• * Amenorrhea more than 6 months and at least age 50
• * Prior HRT regardless of hysterectomy:
• * At least 1 month since prior HRT and less than age 55 with FSH/LH/E2 postmenopausal levels
• * At least 1 month since prior HRT and at least age 55
• * FSH/LH/E2 postmenopausal levels and uncategorized
• No distant metastases, including bone scans showing hot spots unconfirmed as benign disease or skeletal pain of unknown cause
• At least 10% hormone receptor-positive tumor cells
• Hormone receptor status:
• * Estrogen receptor positive AND/OR
• * Progesterone receptor positive
• PATIENT CHARACTERISTICS:
• Age:
• 30 and over
• Sex:
• Female
• Menopausal status:
• Postmenopausal
• Performance status:
• Not specified
• Life expectancy:
• Not specified
• Hematopoietic:
• WBC greater than 3,000/mm\^3
• Platelet count at least 100,000/mm\^3
• Hemoglobin greater than 10 g/dL
• Hepatic:
• Bilirubin less than 3.0 mg/dL
• SGOT or SGPT less than 1.5 times upper limit of normal
• No hepatic disease that would preclude study
• Renal:
• Creatinine less than 1.8 mg/dL
• No renal disease that would preclude study
• Cardiovascular:
• No cardiovascular disease that would preclude study
• Prior deep vein thrombosis allowed if medically stable
• Pulmonary:
• No lung embolism
• Other:
• No other prior or concurrent malignancy within the past 5 years except adequately treated basal or squamous cell skin cancer or carcinoma in situ of the cervix
• No prior noncompliance to medical regimens
• No other nonmalignant systemic diseases that would preclude follow-up
• HIV negative
• PRIOR CONCURRENT THERAPY:
• Biologic therapy:
• Prior immunotherapy or biological response modifiers (e.g., interferon) allowed
• Chemotherapy:
• See Disease Characteristics
• Prior adjuvant or neoadjuvant chemotherapy allowed
• Concurrent adjuvant chemotherapy allowed
• Endocrine therapy:
• See Disease Characteristics
• Prior neoadjuvant hormonal therapy allowed (e.g., antiestrogens, progestins, or aromatase inhibitors) if no more than 4 months duration and no disease progression
• Prior corticosteroids allowed
• At least 4 weeks since prior HRT
• Prior adjuvant antiestrogen therapy allowed if less than 1 month duration and immediately after surgery, radiotherapy, and/or chemotherapy
• Prior antiestrogens for chemoprevention allowed if at least 18 months between completion of chemoprevention and diagnosis
• No other concurrent antiestrogens or aromatase inhibitors
• No concurrent raloxifene
• No concurrent systemic HRT with or without progestins of more than 3 months duration
• Radiotherapy:
• See Disease Characteristics
• Concurrent radiotherapy allowed
• Surgery:
• See Disease Characteristics
• Other:
• At least 30 days since prior systemic investigational drugs
• At least 7 days since prior topical investigational drugs
• Concurrent bisphosphonates allowed