Background: The aim of this study was to assess the early effects of zoledronic acid (ZOL) and oral ibandronate (IBA) on the bone resorption marker s-CTX (serum C-telopeptide of collagen type I) and the bone formation marker B-ALP (bone-alkaline phosphatase) in patients with bone metastases from non-small cell lung cancer (NSCLC).
Methods: Fifty-five patients with at least one site of bone metastasis secondary to NSCLC were randomly assigned to receive intravenous ZOL 4 mg every 4 weeks, or oral IBA 50 mg/day.
Results: At 1 month of treatment, s-CTX was reduced by 54.8% (95% CI 40.4-59.8%) in the ZOL group (26 evaluable patients) compared with 38.2% (95% CI 29.8-48.7%) in the oral IBA group (27 evaluable patients) (p = 0.03). At 3 months, s-CTX was reduced by 72.6% (95% CI 58.6-71.3%) in the ZOL group, compared with 66.4% (95% CI 54.3-79.5%) in the oral IBA group (p = 0.22). Both bisphosphonates similarly decreased the bone marker B-ALP at 1 month (ZOL 24.7%, 95% CI 3.6-39.5%, and IBA 24.2%, 95% CI 2.8-43.4%) and 3 months (ZOL 28.6%, 95% CI +2.8-43.3%, and IBA 24.2%, 95% CI 3.2-47.4%). Both bisphosphonates were well tolerated.
Conclusion: Considering the changes in bone markers, ZOL and oral IBA show comparable efficacy in patients with NSCLC and bone metastases.