Prognostic value of serum uric acid levels following radiotherapy and chemotherapy in nasopharyngeal carcinoma

To evaluate the association between serum uric acid (SUA) levels and prognosis in patients with nasopharyngeal carcinoma (NPC) treated with a comprehensive regimen of induction chemotherapy, intensity-modulated radiation therapy (IMRT), and adjuvant chemotherapy. A total of 182 patients with NPC treated at the Second Affiliated Hospital of Nanchang University between 2017 and 2021 were retrospectively analyzed. SUA levels were recorded at four time points: Pre-treatment, post-induction chemotherapy, post-IMRT and post-adjuvant chemotherapy. Based on the median post-adjuvant chemotherapy SUA level (350.48 µmol/l), patients were stratified into high (SUA >350 µmol/l) and low (SUA ≤350 µmol/l) groups. Survival outcomes were compared using Kaplan-Meier analysis and log-rank tests. Cox proportional hazards models were employed to identify independent prognostic factors. Changes in SUA levels over time were assessed using repeated-measures ANOVA. The high SUA group demonstrated improved 3-year overall survival (OS; P=0.037), progression-free survival (PFS; P<0.001), and distant metastasis-free survival (DMFS; P=0.001) compared with the low SUA group. No significant difference in locoregional relapse-free survival (P=0.41) was observed. Post-adjuvant chemotherapy SUA levels were an independent prognostic factor for OS, PFS and DMFS. Repeated-measures ANOVA showed a significant reduction in SUA levels post-IMRT compared with baseline, post-induction chemotherapy, and post-adjuvant chemotherapy (all P<0.001). In conclusion, elevated post-adjuvant chemotherapy SUA levels are associated with improved survival outcomes in patients with advanced-stage NPC. IMRT induces a transient decrease in SUA levels. These findings suggested that SUA levels may serve as a valuable prognostic biomarker for NPC.