A recent study published in JBMR plus has found that bone-modifying agents such as bisphosphonates (zoledronic acid) and denosumab are associated with improved overall survival in patients with metastatic castration-resistant prostate cancer (mCRPC).

This real-world data analysis, based on a tertiary-care database, investigated the impact of these agents on overall survival (OS) and progression-free survival in patients with at least one bone metastasis.

The study included 420 mCRPC patients, 60% of whom received bone-modifying agents. These patients tended to be younger, had more lines of systemic treatment, and a higher proportion of initial de novo metastatic disease. While the study did not find significant differences in progression-free survival between patients who received bone-modifying agents and those who did not, it did find a significant improvement in overall survival for the group that received bone-modifying agents (58 months vs. 45 months). This survival benefit remained significant even after controlling for other factors.
Within the group that received bone-modifying agents, 57% received denosumab and 43% received bisphosphonates. Although no significant differences in progression-free survival and OS were observed between these two groups, there was a trend towards better progression-free survival for denosumab after adjusting for covariates. The cumulative rate of osteonecrosis of the jaw was 12% in both groups and decreased over time.

The findings suggest that while the administration rate of bone-modifying agents is relatively low in patients with osseous mCRPC, their use is associated with a meaningful survival benefit. Hormonal treatments for mCRPC can lead to osteoporosis and skeletal events which reduces quality of life and overall survival. Bone-modifying agents may help prevent these events. The study concludes that the use of bone-modifying agents in this patient population is beneficial, even after accounting for possible confounding factors.

NOTE: this is a post-hoc, observational study, with all the limits of this kind of studies.

Source.