Effectiveness of Bisphosphonates and Denosumab on Risk of Vertebral Fractures in Prostate Cancer Patients Under Androgen Deprivation Therapies: A Real-World Prospective Study.

OBJECTIVE

This prospective study investigated the real-world effectiveness of bisphosphonates and denosumab in reducing vertebral fracture (VF) risk induced by androgen deprivation therapies (ADTs).

METHODS

Two hundred twenty-six consecutive men (mean age 74.8 ± 6.9 years) undergoing ADT were evaluated for morphometric VFs at baseline and after 26.1 ± 10.7 months of follow-up (range 18-64). Following enrollment, 153 patients commenced bisphosphonates (98 cases) or denosumab (55 cases), while 73 patients (32.3%) received only vitamin D and calcium supplementation. As an additional control group, we enrolled 62 consecutive men (mean age 74.9 ± 7.2 years) under chronic ADTs who had been neither evaluated nor treated for skeletal fragility before study entry.

RESULTS

Incident VFs were found in 16 of 226 (7.1%) patients enrolled in the prospective study and in 18 of 62 (29.0%) control subjects (P < .001). The risk of VFs was significantly lower in patients treated with bone-active drugs as compared to those treated with vitamin D (hazard ratio 0.26, 95% CI 0.09-0.73; P = .01), without significant difference between denosumab and bisphosphonate treatment (P = .423), although denosumab-treated patients had lower bone mineral density, higher serum C-terminal telopeptide of type I collagen values, and more prevalent VFs. Noteworthy, incident VFs were significantly lower in patients receiving vitamin D with calcium as compared to those subjects under chronic ADT who had never been evaluated and treated for skeletal fragility prior to the study (12.3% vs 29.0%; P = .016).

CONCLUSION

In real-world clinical practice, bisphosphonates or denosumab might be effective in reducing the risk of VFs related to ADTs.