Letrozole in Preventing Breast Cancer in Postmenopausal Women

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