Serum uric acid to lymphocyte ratio: A novel prognostic biomarker for surgically resected early-stage lung cancer. A propensity score matching analysis

Abstract Backgrounds This study aims to evaluate the prognostic impact of serum uric acid to lymphocyte ratio (ULR) in video-assisted thoracoscopic surgery (VATS) lobectomy for early-stage non-small-cell lung cancer (NSCLC) through a propensity score-matching (PSM) analysis. Methods This study was carried out based on a prospectively-maintained database in our institution between January 2014 and July 2015. Survival analysis using a log-rank test was performed to distinguish the differences in both overall survival (OS) and disease-free survival (DFS) between the patients stratified according to an optimal cut-point of ULR. Finally, multivariable Cox proportional hazards regression analysis and PSM analysis were conducted to identify the prognostic factors of NSCLC. Results There were 335 patients with surgically resected primary stage I-II NSCLC included. An ULR at 3.83 was found to be the optimal cut-point regarding postoperative survival. Both OS and DFS of the patients with ULR > 3.83 were significantly shortened compared to those of the patient with ULR ≤ 3.83. Patients with ULR > 3.83 had significantly lower rates of OS and DFS until the last follow-up date than those of patients with ULR ≤ 3.83. These differences still remained significant after PSM analysis. Multivariate analyses for the entire cohort finally demonstrated that an elevated ULR could independently predict both unfavorable OS and DFS of surgically resected stage I-II NSCLC. Conclusions ULR can be considered as a novel risk stratification tool to refine prognostic prediction for operable early-stage NSCLC.