Prognostic role of the systemic immune-inflammation in patients with non-small cell lung cancer: a meta-analysis

Abstract Background: Systemic immune-inflammation (SII) has been identified as an independent prognostic factor for many types of cancer. However, there is controversy regarding the prognostic value of SII in assessing non-small cell lung cancer (NSCLC) prognosis. Methods: In this study, we conducted a comprehensive search of the electronic databases of PubMed, Embase, and Cochrane Library up to March 21, 2023, to evaluate the prognostic value of SII in NSCLC. We calculated the hazard ratio (HR) and 95% confidence interval (CI) to assess the relationship between SII and overall survival (OS) or progression-free survival (PFS). Results: Our analysis included 32 studies involving 12,040 patients. The results showed that increased SII was significantly associated with poor OS (HR, 1.31; 95% CI, 1.21-1.41; p<0.001) and PFS (HR, 1.48; 95% CI 1.12-1.94; p<0.001) in NSCLC patients. Subgroup analysis further confirmed these findings. Sensitivity analysis and publication bias results indicated the stability of the results. Conclusions: Our study demonstrates that high SII is a significant predictor of poor OS and PFS in NSCLC patients. Therefore, SII may serve as a useful tool to evaluate the prognosis of NSCLC and guide the development of treatment strategies.