On the horizon: can bisphosphonates prevent bone metastases?

Skeletal complications of bone metastases increase the risk of death and undermine patients' functional independence and quality of life. Although bisphosphonates are integral in the treatment regimen of patients with metastatic bone disease and have demonstrated efficacy in delaying the onset and reducing the incidence of skeletal-related events, there is great interest in developing treatments to prevent metastasis to bone. Emerging evidence indicates that the potential benefits of bisphosphonate therapy extend beyond the treatment of metastatic bone lesions. Data from preclinical studies suggest that bisphosphonates may have antitumour activity and may prevent bone metastasis. The mechanisms of these antitumour effects are currently under investigation and may include induction of apoptosis, inhibition of tumour cell invasion and angiogenesis, and tumour growth reduction. Therefore, patients with early-stage disease may benefit from early bisphosphonate therapy, before bone metastasis develops, and investigations are ongoing to determine the clinical utility of bisphosphonates in this setting.