Prechemoradiotherapy Systemic Inflammation Response Index Stratifies Stage IIIB/C Non-Small-Cell Lung Cancer Patients into Three Prognostic Groups: A Propensity Score-Matching Analysis

Purpose. We explored the prognostic influence of the systemic inflammation response index (SIRI) on the survival outcomes of stage IIIB/C non-small-cell lung cancer (NSCLC) patients who underwent concurrent chemoradiotherapy. Methods. Present propensity score-matching (PSM) analysis comprised 876 stage IIIB/C NSCLC patients who received 1–3 cycles of platinum-based doublets concurrent with thoracic radiotherapy from 2007 to 2017. The primary and secondary objectives were the relationships between the SIRI values and overall (OS) and progression-free survival, respectively. Propensity scores were calculated for SIRI groups to adjust for confounders and to facilitate well-balanced comparability between the SIRI groups by creating 1 : 1 matched study groups. Results. The receiver operating characteristic curve analysis identified an optimal SIRI cutoff at 1.9 for OS (AUC: 78.8%; sensitivity: 73.7%; specificity: 70.7%) and PFS (AUC: 80.5%; sensitivity: 75.8%; specificity: 72.9%) and we grouped the patients into two PSM cohorts: SIRI