Risk of renal failure in cancer patients with bone metastasis treated with renally adjusted zoledronic acid.

Purpose: The purpose of this study was to evaluate the incidence of acute renal failure (ARF) in patients with mild to moderate renal dysfunction, receiving renally adjusted zoledronic acid (ZA) and compare it to patients with normal baseline renal function, receiving standard-dose ZA.

Methods: This was a retrospective study of patients receiving ZA for the treatment of bone metastasis due to cancer. Patients were divided into two groups: (1) normal group with baseline creatinine clearance (CrCl) of greater than 60 mL/min and standard ZA dose; (2) impaired group with baseline CrCl of 30-60 mL/min and renally adjusted ZA dose. Primary endpoint of ARF was defined as an increase in serum creatinine (SCr) of 0.5 mg/dL or 1.0 mg/dL from a baseline SCr of <1.4 mg/dL or ≥ 1.4 mg/dL, respectively.

Results: In total, 1,472 evaluable doses of ZA were given to 220 patients. Of these, 184 patients were in the normal group and 36 patients in the impaired group. There were 38 patients (20.7%) who developed ARF in the normal group versus 7 patients (19.4%) in the impaired group. There was no difference in the mean time to the incidence of ARF at 6.1 months in both groups. Incidence of ARF based on CrCl (≥ 25% decline in CrCl) was similar between groups (39.1% vs. 41.7%; p = 0.78).

Conclusion: The incidence of ARF is similar between patients in the normal group and impaired group when the ZA dose is renally adjusted.