Observational Study of Bone Complications in People With Post-menopausal Breast Cancer Who Have Stopped Treatment With Denosumab and Aromatase Inhibitors

The purpose of this study to gather information about changes in the bones after stopping treatment with aromatase inhibitor/AI and denosumab. The study team will collect information from 5 standard clinic visits over the course of 24 months. The information will include information about participant health assessments, blood test results, and imaging results. After 24 months, participation in this study will be complete.

Inclusion Criteria: * Women with confirmed diagnosis of breast cancer * Participant must be post-menopausal, defined as last menstrual cycle at least 12 months prior to enrollment * Received at least 2 doses of denosumab and then discontinued therapy * Discontinued AI prior to or within 6 months of last denosumab injection * Patients must be 18 years of age or olde Exclusion Criteria: * Patients with history of osteoporosis prior to starting denosumab, based on previous dual-energy X-ray absorptiometry (DEXA) scan; * Patients with history of insufficiency fracture. * Patients who continue treatment with a different bone modifying agent (i.e oral or intravenous bisphosphonates) after discontinuation of denosumab * Patients on chronic low-dose glucosteroids.