Letrozole in Preventing Breast Cancer in Postmenopausal Women

You may be eligible if

• DISEASE CHARACTERISTICS:
• At increased risk for the development or recurrence of breast cancer, defined as an estradiol level ≥ 9 pg/mL
• No evidence of suspicious or malignant disease, based on the following examinations:
• * Clinical bilateral breast examination within the past 6 months
• * Bilateral\* mammogram within 3 months before randomization OR within 30 days after randomization
• * Pelvic exam normal within the past 5 years
• * General physical exam within the past 6 months NOTE: \*Unilateral mammogram of the uninvolved breast for patients with prior invasive breast cancer or ductal carcinoma in situ (DCIS)
• Bone density scan within 2 standard deviations from normal within the past 30 days
• * Bone density scan ≥ 2 standard deviations below normal allowed if approved by the study physician
• At least 1 breast that has not been previously treated with radiotherapy or surgery (for patients with prior invasive breast cancer or DCIS)
• Hormone receptor status:
• * Not specified
• PATIENT CHARACTERISTICS:
• Age
• 35 and over
• Sex
• Female
• Menopausal status
• Postmenopausal, defined by any of the following criteria:
• * At least 12 months without spontaneous menstrual bleeding
• * Prior hysterectomy and bilateral salpingo-oophorectomy
• * ≥ 55 years of age with a prior hysterectomy with or without oophorectomy
• * \< 55 years of age with a prior hysterectomy without oophorectomy OR the status of the ovaries is unknown AND follicle-stimulating hormone (FSH) level is in the postmenopausal range
• Performance status
• Normal activity must not be restricted for a significant portion of the day
• Life expectancy
• At least 10 years
• Hematopoietic
• Complete blood count with differential normal
• * Prior benign neutropenia allowed provided the granulocyte count is ≥ 1,500/mm\^3
• Hepatic
• Bilirubin normal
• Alkaline phosphatase normal
• SGOT and SGPT normal
• Renal
• Creatinine normal
• Cardiovascular
• No uncontrolled cardiovascular disease
• Other
• Not pregnant
• No other malignancy within the past 5 years except basal cell or squamous cell skin cancer or carcinoma in situ of the cervix
• No osteoporosis
• No hyperlipidemia
• No mental health status resulting in cognitive or emotional impairment that would preclude study participation
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• Not specified
• Chemotherapy
• Not specified
• Endocrine therapy
• More than 30 days since prior AND no concurrent use of any of the following hormonal agents:
• * Estrogen or progesterone replacement therapy
• * Oral contraceptives
• * Raloxifene or other plasma estrogen receptor modulators (SERMs)
• * Androgens (e.g., danazol)
• * Luteinizing hormone-releasing hormone (LHRH) analogs (e.g., goserelin or leuprolide)
• * Prolactin inhibitors (e.g., bromocriptine)
• * Antiandrogens (e.g., cyproterone)
• More than 60 days since prior AND no concurrent tamoxifen
• No prior aromatase inhibitors (for patients with prior invasive breast cancer or DCIS)
• No concurrent phytoestrogenic dietary supplements (e.g., soy, ginseng, or other natural products)
• * Dietary soy allowed
• Radiotherapy
• See Disease Characteristics
• Surgery
• See Disease Characteristics
• No prior bilateral mastectomy
• Other
• More than 60 days since prior treatment for invasive breast cancer or DCIS
• More than 30 days since prior bisphosphonates or calcitonin
• No prior or concurrent participation on a treatment study for invasive breast cancer or DCIS
• No concurrent participation in any other cancer prevention study or osteoporosis prevention study involving pharmacologic agents
• No concurrent calcitonin
• No concurrent bisphosphonate therapy
• Concurrent cholecalciferol (vitamin D) and calcium to augment bone mineral density allowed