Letrozole in Preventing Breast Cancer in Postmenopausal Women Who Are at Increased Risk for Breast Cancer Due to High Breast Density

DISEASE CHARACTERISTICS:

• At increased risk for the development or recurrence of breast cancer, as defined by 1 of the following:

  • Baseline mammogram indicating mammographic density occupying ≥ 25% (grade 4/6, 5/6, or 6/6) of the breast tissue

    • No suspicion of breast cancer, unless subsequently ruled out

  • Prior ductal carcinoma in situ (DCIS)

    • Untreated disease OR > 6 months since completion of adjuvant endocrine therapy
    • Receptor status of lesion is not required

  • Prior invasive breast cancer

    • Breast cancer must have been surgically removed at time of original diagnosis with no evidence of metastases
• No clinical evidence of breast cancer

• Acceptable quality dual-energy x-ray absorptiometry (DEXA) of the L2-L4 postero-anterior (PA) spine and hip performed within past 6 months

  • Bone mass density T-score of either PA spine or hip must be ≥ 2.0 SD below the mean peak bone mass in young normal woman
• Stable chronic leukemia allowed

• Hormone receptor status:

  • Hormone receptor-negative, -positive, or -equivocal tumor

PATIENT CHARACTERISTICS:

Age

• Postmenopausal

Sex

• Female

Menopausal status

• Postmenopausal, as defined by 1 of the following:

  • Over 55 years of age with spontaneous cessation of menses for ≥ 1 year
  • 55 years of age and under with spontaneous cessation of menses for ≤ 1 year, but amenorrheic (e.g., spontaneous or secondary to hysterectomy) AND follicle-stimulating hormone level > 34.4 IU/L
  • Bilateral oophorectomy

Performance status

• Not specified

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Not specified

Cardiovascular

• No recent unstable myocardial infarction
• No prior stroke
• No high blood pressure
• No other uncontrolled cardiovascular disease

Other

• Other prior malignancies without metastatic disease allowed
• Willing and able to complete quality of life questionnaires in either English or French
• No uncontrolled metabolic or endocrine disease
• No malabsorption syndrome

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No concurrent immunotherapy

Chemotherapy

• No concurrent chemotherapy

Endocrine therapy

• See Disease Characteristics
• At least 3 months since prior and no concurrent hormone replacement therapy or raloxifene
• At least 6 months since prior tamoxifen
• No concurrent steroid therapy
• No concurrent selective estrogen-receptor modulators
• No other concurrent endocrine or hormonal therapy

Radiotherapy

• Not specified

Surgery

• See Disease Characteristics