Denosumab and MRI Breast Imaging

Inclusion Criteria: * Pre or postmenopausal women with first incidence of early stage (stages 0 - III) breast cancer who have completed all treatment and are cancer-free, which includes women at high risk for developing invasive cancer i.e. having a breast biopsy positive for atypical ductal or lobular hyperplasia or carcinoma in situ. * Age ≤ 75 years * 44 patients will be accrued as follows: a) 22 evaluable patients will be premenopausal as defined as regular menses (24-38 days) b) 22 evaluable patients will be postmenopausal as defined by a history of amenorrhea for at least one year or hormone levels (estradiol/FSH) consistent with menopause if post-hysterectomy status, or history of surgical/medical castration. * Normal serum calcium or albumin-adjusted serum calcium between 2.0 and 2.9 mmol/L (8.0-11.5mg/dL). * Adequate vitamin D level (25-hydroxy vitamin D level \> 20 ng/mL) * Currently on no active treatment for breast cancer and at least 3 months post all the treatments, with the exception of aromatase inhibitors (exemestane, anastrozole, letrozole) * No prior or current use of IV bisphosphonates * No current use of oral bisphosphonates * Patients must have an unaffected, non-irradiated contralateral breast * Significant breast density as determined by mammography and defined by the descriptive terms scattered fibroglandular tissue/densities, heterogeneously dense, or mostly dense tissue in the mammography report. * Adequate renal function defined as a serum creatinine \< 1.5 x ULN or CrCl \> 30mL/min * A willingness and ability to follow the study protocol, as indicated by provision of informed consent to participate * Willingness to being tested for current pregnancy and use of birth control while being treated with denosumab (pre-menopausal women only) Exclusion Criteria: * Age \> 75 years * Subject has known sensitivity to any of the products to be administered during the study (e.g., mammalian derived products, denosumab, calcium, or vitamin D). * Patients have prior history or current evidence of osteonecrosis or osteomyelitis of the jaw. * Patients have active dental or jaw condition which requires oral surgery, including tooth extraction. * Patients have non-healed dental or oral surgery, including tooth extraction. * Patients with planned invasive dental procedures * Subject is pregnant or breast feeding, or planning to become pregnant within 5 months after the end of the treatment * Subject is of child bearing potential and is not willing to use, in combination with her partner, highly effective methods of contraception or abstinence during treatment and for 5 months after the end of treatment * Active infection with Hepatitis B, Hepatitis C, or Human Immunodeficiency virus (HIV) * Any condition or disorder that compromises the ability of the subject to provide written informed consent and/or comply with study procedures * History of claustrophobia * Have electrically, magnetically, or mechanically activated implants including cardiac pacemaker, cochlear implants, magnetic surgical clips or prostheses.