Acolbifene in Preventing Cancer in Premenopausal Women at High Risk of Breast Cancer

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