Abstract
PURPOSE: Uric acid (UA) is a major antioxidant molecule that has been hypothesized to have a protective effect against cancer-induced oxidative damage. The aim of the present study was to investigate whether preoperative levels of serum UA are associated with the prognosis of laryngeal squamous cell cancer (LSCC). METHODS: A total of 814 male LSCC patients (followed up for five years) and 814 normal control subjects were enrolled from January 2007 to December 2011. The rates of total mortality and cancer mortality were 23.46% and 21.36%, respectively. The prevalence of overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) was analysed using the Kaplan-Meier method. Univariate and multivariate Cox regression models were evaluated to identify UA as a prognostic factor. RESULTS: The serum UA and UA/Cr (creatinine) ratio levels were significantly reduced (P < 0.001 for both) in the LSCC group compared with the control group. The applied multivariate Cox regression model analysis found that low levels of UA and the UA/Cr ratio were independent poor prognostic factors for OS (UA (HR (95% CI) = 1.458 (1.095-1.942)), UA/Cr ratio (HR (95% CI) = 1.337 (1.004-1.780))), DFS (UA (HR (95% CI) = 1.504 (1.131-2.001)), UA/Cr ratio (HR (95% CI) = 1.376 (1.030-1.839))), and CSS (UA (HR (95% CI) = 1.494 (1.109-2.012)), UA/Cr ratio (HR (95% CI) = 1.420 (1.049-1.923))). The patients with high UA (>0.310 mmol/l) and UA/Cr ratio (>3.97) experienced five more years of OS, DFS, and CSS than did patients with low UA (<0.310 mmol/l) and UA/Cr ratio (<3.97) levels. CONCLUSION: High preoperative UA serum levels were identified as an independent prognostic factor associated with improved clinical outcomes among LSCC patients.