Systemic immune-inflammation index changes predict outcome in stage III non-small-cell lung cancer patients treated with concurrent chemoradiotherapy.

Background: Although the systemic immune-inflammation index (SII) has been used to predict recurrence and survival in non-small-cell lung cancer (NSCLC) patients, the prognostic significance of change in SII (ΔSII) is unclear for stage III NSCLC patients treated with concurrent chemoradiotherapy (CCRT). In the present study we aimed to explore the association between ΔSII and the clinical outcomes of 142 patients with stage III NSCLC treated with CCRT. Methods: A total of 142 patients were included in this retrospective study. The SII values were calculated based on laboratory data regarding platelet, neutrophil and lymphocyte counts, and ΔSII was calculated using data acquired before and approximately 2 weeks after CCRT. The receiver operating characteristic curve was used to determine the optimal cut-off value for the peripheral blood inflammation index. Kaplan-Meier analysis and Cox proportional regression were used to analyze the prognostic value of ΔSII for overall survival (OS) and progression-free survival (PFS). Results: The area under the receiver operating characteristic curve for ΔSII (0.708) was larger than those for pre-CCRT SII (0.578) and post-CCRT SII (0.610). The optimal cut-off point for ΔSII was defined as 43. OS and PFS were better in patients with low ΔSII and in multivariate analysis, the ΔSII was an independent predictor of OS and PFS (p = 0.006 and p = 0.017, respectively). Conclusions: ΔSII is related to progression and death in patients with stage III NSCLC. The ΔSII can provide a detailed prognostic prediction for stage III NSCLC.