Statement: Women classified as high-risk of developing breast cancer within the next 5 years and within her lifetime by the Gail model are eligible for the primary trial.
Primary_evidence: Inclusion Criteria:   Gail risk >= 1.7% and/or relative risk >= 3 times that for 5-year age group   Premenopausal   More than 6 months since initiating or discontinuing oral contraceptives   At increased risk for breast cancer, as indicated by >= 1 of the following risk factors:   BRCA1/2 mutation characterized as deleterious or of uncertain significance   Prior atypical ductal hyperplasia, ductal carcinoma in situ, or lobular carcinoma in situ   Prior random periareolar fine needle aspiration (RPFNA) showing atypical hyperplasia   Family history consistent with hereditary breast cancer, as indicated by 1 of the following criteria:   >= 4 relatives with breast cancer   >= 2 relatives diagnosed with breast cancer at  50 years of age   Breast and ovarian cancer diagnosed in same relative   No suspicion for breast cancer on baseline mammogram performed between days 1-10 of menstrual cycle within 3 months prior to screening baseline RPFNA   Exhibits hyperplasia with or without atypia (Masood score >= 14) with >= 500 cells AND Ki-67 positivity >= 2% by RPFNA performed within 6 months prior to initiation of study drug   Estimated visual mammographic breast density category >= 5% on mammogram performed within 6 months prior to initiation of study drug   Has regular menstrual cycles (between 21 and 35 days) unless using extended regimen oral contraceptives or a contraceptive device (e.g., Mirena IUD) Values for metabolic profile and blood count within normal limits   Absolute granulocyte count > 1,000/mm^3   Platelets > 100,000/mm^3   Hemoglobin > 10 g/dL   Bilirubin < 2.0 mg/dL   AST < 2 times upper limit of normal (ULN)   Albumin > 3.0 g/dL   Creatinine < 1.5 mg/dL   Alkaline phosphatase < 2 times ULN   Concurrent hormonal contraceptives allowed provided patient remains on the same hormonal regimen from 3 months prior to baseline aspiration until the completion of study treatment   Fertile patients must use effective contraception during and for 3 months after completion of study treatment   Willing to ingest recommended dose of calcium and vitamin D for premenopausal bone health (1,200 mg calcium and 800 IU vitamin D daily)   Negative pregnancy test prior to receiving study agent   Exclusion Criteria   pregnant or nursing   nursing within the past 6 months   Known osteoporosis or severe osteopenia (T-score -2 or worse by DEXA)   History of symptomatic endometriosis with pelvic pain, poorly controlled migraines, or hot flashes   History of deep venous thrombosis   History of allergic reactions attributed to compounds of similar chemical or biological composition to the study agent   Other condition or concurrent illness that, in the opinion of the investigator, would make the patient a poor candidate for RPFNA   Less than 1 year since prior use of aromatase inhibitors (e.g., anastrozole, exemestane, or letrozole) or selective estrogen receptor modulators (e.g., tamoxifen citrate, raloxifene, or arzoxifene hydrochloride)   Other concurrent chemopreventive agents   Concurrent anticoagulants   Other concurrent investigational agents   Bilateral breast implants