Denosumab versus pamidronate in the treatment of osteolytic bone metastases secondary to breast cancer: a multi-institutional analysis.

BACKGROUND: Breast cancer is the most common cancer in women and most often metastasizes to the bone, resulting in skeletal-related events (SREs). Bone-modifying agents (BMAs) including denosumab, a monoclonal antibody against the receptor activator of nuclear factor kappa-b ligand (RANKL), and pamidronate, a bisphosphonate, are used to prevent these adverse events.

METHODS: To analyze the efficacy of denosumab versus pamidronate, we used the TriNetX research platform and compared the outcomes of pathologic fracture, spinal cord compression, and overall 5-year survival rate between each pharmacotherapy.

RESULTS: There was no statistical difference for an increased risk in pathological fractures (2.7% vs. 2.8%, P  = 0.88), spinal cord compression (2.6% vs. 2.7%, P  = 0.88), or 5-year survival rate (45.5% vs. 52.4%, P  = 0.78) for the denosumab cohort versus the pamidronate cohort.

CONCLUSION: Since neither therapy showed an increased risk in the adverse effects measured in this study, factors such as patient preference, financial costs, and additional side effects of each medication should be taken into consideration when choosing a therapy for bone metastases in patients with breast cancer.