Bone is the most common site of spread of breast cancer and bone metastases will occur in roughly 70% of women with advanced disease. These patients are at risk of developing bone complications that cause significant impact on both patient morbidity and mortality. Close to two-thirds of women with bone metastases will go on to develop at least one of these complications, termed a skeletal related event (SRE), defined as 1) pathological fractures, 2) pain requiring radiation or surgical intervention, 3)spinal cord compression, and 4) hypercalcemia. In addition to SREs, most breast cancer patients with bone metastases have some degree of pain associated with their disease. Understandably these factors negatively impact their quality of life. Furthermore, the development of an SRE in this population has been shown to be associated with shorter overall survival. Prevention or delay in onset of these complications is therefore an important therapeutic goal.