Anastrozole in Preventing Breast Cancer in Postmenopausal Women at Increased Risk of Breast Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Meets at least 1 of the relative risk factors based on age as follows:
• * 45 to 70 years of age:
• * First-degree relative who developed breast cancer at ≤ 50 years of age
• * First-degree relative who developed bilateral breast cancer
• * Two or more first- or second-degree relatives who developed breast cancer or ovarian cancer
• * Participants having both relatives who are second degree and on the opposite sides of the family must have at least one that was diagnosed at ≤ 50 years of age
• * Nulliparous (or first birth at ≥ 30 years of age) and a first-degree relative who developed breast cancer
• * Benign biopsy with proliferative disease and a first-degree relative who developed breast cancer
• * Mammographic opacity covering at least 50% of the breast in the absence of hormone replacement therapy within the past 3 months
• * 60 to 70 years of age:
• * First-degree relative with breast cancer at any age
• * Age at menopause ≥ 55 years
• * Nulliparous or age at first birth ≥ 30 years
• * 40 to 44 years of age:
• * Two or more first- or second-degree relatives who developed breast cancer or ovarian cancer at ≤ 50 years of age
• * First-degree relative with bilateral breast cancer who developed the first breast cancer at ≤ 50 years of age
• * Nulliparous (or first birth at ≥ 30 years of age) and a first-degree relative who developed breast cancer at ≤ 40 years of age
• * Benign biopsy with proliferative disease and a first-degree relative who developed breast cancer at ≤ 40 years of age
• All age groups (40 to 70 ears of age) with a 10-year risk \> 5% who do not fit into the above categories are allowed
• * Clearly apparent family history AND/OR other risk factors indicating appropriate increased risk of breast cancer for age
• The following prior breast conditions are allowed (for all age groups):
• * Lobular carcinoma in situ
• * Atypical ductal or lobular hyperplasia in a benign lesion
• * Ductal carcinoma in-situ (DCIS), diagnosed within the past 6 months, and treated by mastectomy
• No evidence of breast cancer on mammogram within the past year
• Hormone receptor status:
• * For patients with prior DCIS, estrogen- or progesterone-receptor status must have been positive
• * Must have had greater than or equal to 5% positive cells
• PATIENT CHARACTERISTICS:
• Age
• 40 to 70
• Sex
• Female
• Menopausal status
• Postmenopausal, defined as at least 1 of the following:
• * Over 60 years of age
• * Bilateral oophorectomy
• * ≤ 60 years of age with a uterus and amenorrhea for at least 12 months
• * ≤ 60 years of age without a uterus and with follicle-stimulating hormone levels \> 30 IU/L
• Performance status
• Not specified
• Life expectancy
• At least 10 years
• Hematopoietic
• Not specified
• Hepatic
• Not specified
• Renal
• Not specified
• Other
• Psychologically and physically suitable to receive 5 years of anti-estrogen therapy
• No cancer within the past 5 years except non-melanoma skin cancer or carcinoma in situ of the cervix
• No evidence of osteoporosis or fragility fractures within the spine
• * Participants with a T-score \> minus 4 and no more than 2 fragility fractures are allowed
• No concurrent severe disease that would place the participant at unusual risk or confound the results of the study
• No other medical condition that would preclude the ability to receive the study treatment
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• Not specified
• Chemotherapy
• Not specified
• Endocrine therapy
• No prior tamoxifen, raloxifene, or other selective estrogen receptor modulator (SERM) use for more than 6 months in duration unless an IBIS-I participant (must have been off trial therapy for at least 5 years.
• No concurrent tamoxifen, raloxifene, or other SERM
• No concurrent estrogen-based hormone replacement therapy
• No concurrent systemic estrogen replacement therapy, including vaginal estrogen preparations
• Radiotherapy
• Not specified
• Surgery
• See Disease Characteristics
• No prior prophylactic mastectomy
• No concurrent prophylactic mastectomy
• Other
• More than 6 months since prior investigational drugs