Bone-targeted therapy in metastatic breast cancer - all well-established knowledge?

Bone-targeted therapies like bisphosphonates (zoledronic acid or pamidronate) or denosumab are recommended in all patients with metastatic breast cancer and bone metastases, whether they are symptomatic or not. The choice between these 2 different agents, however, remains open. In this review, we critically discuss the emerging evidence for direct anti-tumor activity of bone-targeting agents, the utility of bone turnover markers for treatment decision and efficacy prediction, as well as the safety and financial aspects of bisphosphonates and denosumab. Furthermore, we provide a possible therapeutic algorithm, and present new pharmacologic agents which are being investigated for the treatment of metastatic bone disease.