Statins and Breast Cancer Biomarkers

Inclusion Criteria: * Women willing and able to give written informed consent * Pre-menopausal women with regular menstrual cycles (4 cycles in the past 6 months) * At least 35 years of age * Women at increased risk of developing breast cancer, defined as at least one of the following four criteria: * Having had a biopsy demonstrating atypical hyperplasia or lobular neoplasia/LCIS * A germline mutation in BRCA1/2 in themselves or their family. * A Gail Model Risk of \> 1.67% over 5 years * A strong family history of breast and/or ovarian cancer which is defined as at least one of the following: * One first-degree relative with breast cancer before the age of 50 years * One first degree relative with bilateral breast cancer * Two or more first-degree relatives with breast cancer * One first degree relative and two or more second or third degree relatives with breast cancer * One first-degree relative with breast cancer and one or more relatives with ovarian cancer * Two second or third degree relatives with either breast cancer and one or more with ovarian cancer * One second or third degree relative with breast cancer and two or more with ovarian cancer * Three or more second or third degree relatives with breast cancer * A prior history of breast cancer, including DCIS and stage 0-IIIb, and are at least one year off of all therapy (including radiation, biologic, hormonal and/or chemotherapy) Exclusion Criteria: * Women with a prior history of stage IV breast cancer or ovarian cancer * Women already taking statins. Women previously on statins may participate if they have not taken any statins in the six months prior to study entry * Women concurrently participating in another breast cancer chemoprevention trial * Women taking hormone replacement therapy (estrogen and progesterone; topical estrogen will be allowed) * Women taking tamoxifen, raloxifene, or an aromatase inhibitor * Women taking drugs that increase risk of statin induced myopathy or rhabdomyolysis (i.e., Niacin, protease inhibitors, verapamil, gemfibrozil, cyclosporine, clofibrate/fenofibrate or any CYP3A4 inhibitor) * Women with underlying liver disease or abnormal liver studies including: * alkaline phosphatase, ALT, AST and Bilirubin (greater than 1.5 times normal) * Women who have had hypersensitivity to atorvastatin or any component of the formulation * Women who are pregnant, planning pregnancy within the next year, or breastfeeding