Role of zoledronic acid in nasopharyngeal carcinoma patients with bone-only metastasis at diagnosis

Abstract

Objective: We aimed to investigate whether zoledronic acid (ZA) can prevent skeletal-related events (SREs) and offer survival benefits for nasopharyngeal carcinoma (NPC) patients with bone-only metastasis at diagnosis.

Materials and methods: A total of 228 newly diagnosed NPC cases with bone-only metastasis were eligible for this retrospective study. Using the propensity score method (PSM) method, a well-balanced cohort was created for further analysis. Overall survival (OS) was the primary endpoint. The difference in survival was evaluated using the log-rank test. Hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality were derived from a Cox regression model. Cumulative incidence competing risk analyses using Fine and Gray's method was used to test the cumulative incidence of SREs between the different treatment groups.

Result: In the PSM cohorts, patients in the platinum-based palliative chemotherapy (PCT) + ZA group and PCT alone group achieved similar 3-year OS (57.3% vs. 46.4%; log rank P = 0.188). Multivariate analysis indicated that ZA administration was not an independent prognostic factor (HR, 0.783; 95% CI, 0.267-2.300; P = 0.657). There was no significant difference in acute treatment toxicity between the 2 treatment groups, although the cumulative incidence of bone-related events (SREs) was significantly lower in the PCT + ZA group (Fine-Gray P = 0.026).

Conclusion: ZA combined with PCT could not improve OS in NPC patients with bone-only metastasis at diagnosis. However, the incidence of SREs could be effectively prevented via ZA application.

Keywords: Nasopharyngeal carcinoma; Overall survival; Zoledronic acid.