The postoperative neutrophil-to-lymphocyte ratio and changes in this ratio predict survival after the complete resection of stage I non-small cell lung cancer

PURPOSE Although numerous studies have demonstrated associations between the preoperative neutrophil-to-lymphocyte ratio (NLR) and long-term outcomes in patients with non-small cell lung cancer (NSCLC), the prognostic significance of postoperative NLR and change in NLR (ΔNLR) is unknown for patients who underwent complete resection of stage I NSCLC. The aim of this retrospective study was to evaluate the prognostic significance of postoperative NLR and ΔNLR in 123 patients with stage I NSCLC. PATIENTS AND METHODS This retrospective study included preoperative and postoperative data of 123 patients who underwent surgical resection for stage I NSCLC. The relationship between disease-free survival (DFS), overall survival (OS), and clinicopathological factors, including NLR, lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio, and their changes, was analyzed using both univariate Kaplan-Meier and multivariate Cox regression methods. RESULTS The 5-year DFS and OS rates in our cohort were 60.16% and 67.48%, respectively. Univariate analysis revealed that age (P=0.045), smoking status (P=0.033), preoperative NLR (P=0.032), postoperative NLR (P<0.001), ΔNLR (P=0.004), and change in LMR (ΔLMR) (P=0.025) were significant predictors of DFS and that age (P=0.039), smoking status (P=0.042), postoperative NLR (P<0.001), ΔNLR (P=0.004), and ΔLMR (P=0.011) were independent predictors of OS. Multivariate analysis confirmed that postoperative NLR (hazard ratio [HR] =2.435, P=0.001) and ΔNLR (HR =2.103, P=0.012) were independent predictors of DFS and that postoperative NLR (HR =2.747, P=0.001) and ΔNLR (HR =2.052, P=0.018) were significant prognostic factors of OS. CONCLUSION Our study reported for the first time that postoperative NLR and ΔNLR - but not preoperative NLR - were independent prognostic factors of DFS and OS in patients with stage I NSCLC who underwent complete resection. This easily available biomarker might be helpful in individual risk assessment.