Simvastatin and Anastrozole in Treating Postmenopausal Women With Ductal Carcinoma In Situ or Invasive Breast Cancer

DISEASE CHARACTERISTICS: Meets any of the following criteria: History of invasive breast cancer History of ductal carcinoma in situ At high risk for breast cancer, defined as being on anastrozole for chemoprevention of breast cancer Receiving anastrozole for ≥ 30 days as adjuvant breast cancer treatment or for prevention of breast cancer No active breast cancer with known metastatic involvement Hormone receptor status not specified PATIENT CHARACTERISTICS: Female Postmenopausal ECOG performance status 0-2 AST and ALT ≤ 3 times upper limit of normal Creatinine clearance ≥ 30 mL/min No active liver disease No prior hypersensitivity to any HMG-CoA reductase inhibitor or any of its components No daily alcohol use of > 3 standard drinks/day A standard drink is defined as 10 g of alcohol, which is equivalent to 285 mL of beer, 530 mL of light beer, 100 mL of wine, or 30 mL of liquor PRIOR CONCURRENT THERAPY: See Disease Characteristics No cholesterol-lowering drug, including a statin, within the past 3 months No selective estrogen receptor modulator (SERM) within the past 3 months No other hormone therapy within the past 3 months No prior estrogen and/or progesterone hormone replacement therapy that lasted for ≥ 5 years Vaginal estrogen preparations allowed No other concurrent statin or cholesterol-lowering drug No other concurrent SERM No other concurrent hormone therapy No other concurrent investigational drugs No concurrent CYP3A4 inhibitors, including itraconazole, ketoconazole, erythromycin, clarithromycin, telithromycin, HIV protease inhibitors, nefazodone, or cyclosporine No concurrent chemotherapy or biological agents No concurrent daily grapefruit juice > 8 oz/day No other concurrent anticancer agents or therapies