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

Participants are post- menopausal with a breast cancer diagnosis who received at least 2 doses of denosumab, and then discontinued therapy, and discontinued Aromatase Inhibitors/AI prior to or within 6 months of stopping denosumab

Participants will be assessed at Timepoint 0 (last dose of denosumab injection) and then at 9,12,18 and 24 months following discontinuation of denosumab. The evaluation will include history and pain assessment for development of new fractures, weight and height measurement with BMI (body mass index) calculation, and blood work for bone turnover markers (including serum carboxy-terminal collagen crosslinks (CTX) in serum and bone specific alkaline phosphatase). Bone turn-over markers should be drawn in the morning, after at least 8 hours of fasting (water, black coffee and plain tea allowed).

Dual-energy X-ray absorptiometry (DEXA) scans will be performed at the 12 months timepoint , and then at the 24 month timepoint.

TBS is an innovative gray-level texture measurement that utilizes lumbar spine DEXA images to discriminate changes in bone microarchitecture. Specifically, TBS measures bone quality through tridimensional bone areas with different trabecular and microstructural characteristics. The combination of TBS microstructure evaluation with bone density measured by DEXA has been shown to be superior to either measurement alone in the assessment of fracture risk.