Costs and consequences of using pamidronate compared with zoledronic acid in the management of breast cancer patients in the UK.

Objective: To estimate the costs and consequences of using pamidronate compared to zoledronic acid in the prophylactic management of skeletal morbidity among breast cancer patients in the UK.

Design And Setting: This was a modelling study performed from the perspective of the UK's National Health Service (NHS).

Methods: Published clinical outcomes from a comparative study were combined with resource utilisation estimates derived from a panel of clinicians. This enabled the construction of a decision model depicting the management of patients with breast cancer receiving antineoplastic therapy who are 18 years of age or above and who have at least one bone metastasis (lytic or mixed). There are no significant differences in outcome between using pamidronate and zoledronic acid in breast cancer patients. Therefore, a cost minimisation analysis was performed to identify the treatment strategy that achieves the same outcome for least cost. The expected time attributable to a pamidronate and zoledronic acid infusion was also estimated.

Main Outcome Measures And Results: Starting treatment with pamidronate among patients receiving chemotherapy is expected to lead to a healthcare cost of 6046 pounds over 12 months compared to 6981 pounds with zoledronic acid. In comparison, for patients receiving hormonal therapy, starting treatment with pamidronate is expected to lead to a healthcare cost of 5401 pounds over 12 months compared to 6043 pounds with zoledronic acid. This cost difference is primarily due to the lower acquisition cost of pamidronate and fewer tests among pamidronate-treated patients. Accordingly, pamidronate affords a less expensive management modality. Multivariate analysis showed the expected time attributable to a pamidronate infusion to be 110 to 277 minutes compared with 136 to 296 minutes for a zoledronic acid infusion.

Conclusion: Use of pamidronate instead of zoledronic acid affords an economic benefit to the NHS. Moreover, published clinical trials show no statistical difference between pamidronate and zoledronic acid at 1 year. Hence, within the limitations of our model and the published evidence, pamidronate is the preferred first-line intravenous bisphosphonate for use in breast cancer patients receiving antineoplastic therapy who are 18 years of age or above and who have at least one bone metastasis (lytic or mixed).