Optimising the use of bone-targeted agents in patients with metastatic cancers: a practical guide for medical oncologists.

Bone metastases can be associated with a significant worsening of patient morbidity and mortality. Bisphosphonates have been extensively researched and shown to delay the onset and reduce the incidence of complications from bone metastases. The most commonly used bisphosphonates are intravenous pamidronate, intravenous ibandronate, intravenous zoledronic acid and oral/intravenous clodronate. Several bone-targeted agents with innovative mechanisms of action are currently being developed. These include receptor activator of nuclear factor-kB ligand (RANKL) inhibitors, CCR1 inhibitors, Src inhibitors, DKK1-neutralising antibodies, activin antagonists and endothelin-1 inhibitors. In an era of individualised medicine, oncologists are being faced with an increasing number of questions when dealing with bone-targeted agents. These questions not only include the choice of which drug to use (i.e. bisphosphonates or RANKL inhibitor) but also the best treatment strategy to use. This review will provide medical oncologists with a practical guide to the use of bone-targeted agents.