Novel systemic inflammation response index to predict prognosis after thoracoscopic lung cancer surgery: a propensity score-matching study

Background Our propensity score-matching (PSM) study evaluated the prognostic significance of systemic inflammation response index (SIRI) for patients undergoing video-assisted thoracoscopic surgery lobectomy for non-small-cell lung cancer (NSCLC). Methods This study was conducted on prospectively maintained database in our institution between December 2013 and March 2015. Pre-operative SIRI was calculated by peripheral monocyte x neutrophil/lymphocyte counts. Survival analysis was performed to distinguish differences in post-operative survival between patients stratified by an optimum cut-off of SIRI. Multivariable Cox proportional hazards regression models were established to determine independent prognostic factors. Results There were 390 patients with resected NSCLC included. A SIRI of 0.99 was identified as the optimum cut-off regarding to post-operative survival. Both overall survival (OS) and disease-free survival (DFS) in patients with SIRI >0.99 were significantly shortened than those in patient with SIRI <= 0.99. Patients with SIRI >0.99 had significantly lower rates of OS and DFS compared to those patients with SIRI <= 0.99. These differences still remained significant after subgroup analyses and PSM analyses. Multivariable analyses on the entire cohort and the PSM cohort commonly demonstrated that high pre-operative SIRI could be an independent prognostic factor for unfavourable OS and DFS of NSCLC. Conclusions SIRI serves as a novel risk stratification tool to refine prognostic prediction for surgically resected NSCLC. SIRI may help surgeons to screen high-surgical-risk patients and formulate individualized treatment schemes.