Anticancer effect of bisphosphonates: new insights from clinical trials and preclinical evidence.

Bisphosphonates (BPs) are cornerstones in the treatment of patients with compromised skeletal integrity (either cancer related or not). However, a major indication for BPs use remains the treatment of patients with advanced cancer metastatic to the bone. Recently, several observations derived from clinical trials, primarily aimed at establishing the impact of BPs on the bone health of cancer patients, suggested a potential role for these agents as direct anti-tumor drugs. Consequently, a series of preclinical works were produced with the aim of clarifying the mechanism underlying this observed effect. However, the impact of such data is still under debate owing to the intrinsic weakness of observations from trials not adequately powered to support them. In conclusion, the entire matter remains one of the most intriguing in oncology, and data from ongoing and planned future studies will surely provide us with more information on the great potential of BPs in the adjuvant setting.