Postoperative Elevations of Neutrophil-to-lymphocyte and Platelet-to-lymphocyte Ratios Predict Postoperative Pulmonary Complications in Non-small Cell Lung Cancer Patients: A Retrospective Cohort Study.

The neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) are found to increase in patients who develop postoperative complications (PCs). The aim of the present study was to explore the association of the perioperative changes of NLR (ΔNLR) and PLR (ΔPLR) with PCs in non-small cell lung cancer (NSCLC). Clinical data of 509 patients, who were diagnosed with NSCLC and underwent thoracoscopic radical resection between January 1, 2014 and July 31, 2016 at the Department of Thoracic Surgery, West China Hospital, were reviewed. Patients were divided into PC and non-PC groups, and clinical characteristics including ΔNLR and ΔPLR were compared between them. The optimal cut-off values of ΔNLR and ΔPLR were determined by receiver operating characteristics (ROC) curves and patients were assigned to high ΔNLR/ΔPLR and low ΔNLR/ΔPLR groups in terms of the cut-off values. Clinicopathologic characteristics and the incidence of different PCs were compared between the dichotomized groups. Univariate and multivariate logistic regression analyses were performed to identify the independent risk factors for PCs. The results showed that the ΔNLR and ΔPLR in the PC group were signifcantly higher than those in the non-PC group (P<0.001 for both). The optimal cutoff values of ΔNLR and ΔPLR were 6.6 and 49, respectively. Patients with ΔNLR>6.6 or ΔPLR>49 were more likely to experience postoperative pulmonary complications (PPCs) (P<0.001 for both). Multivariate logistic regression analysis demonstrated that smoking [odds ratio (OR): 2.450, 95% confdence interval (95% CI): 1.084-5.535, P=0.031)], tumor size (OR: 1.225, 95% CI: 1.047-1.433, P=0.011), ΔNLR>6.6 (OR: 2.453, 95% CI: 1.224-4.914, P=0.011) and ΔPLR>49 (OR: 2.231, 95% CI: 1.182-4.212, P=0.013) were predictive of PPCs. In conclusion, the ΔNLR and ΔPLR may act as novel predictors for PPCs in NSCLC patients undergoing thoracoscopic radical lung resection, and patients with ΔNLR>6.6 or ΔPLR>49 should be treated more actively to prevent or reduce PPCs.