Predictive value of neutrophil-lymphocyte ratio and platelet-lymphocyte ratio in non-small cell lung cancer patients treated with immune checkpoint inhibitors: A meta-analysis

Background: High neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are associated with poor prognosis in cancer patients treated with Immune checkpoint inhibitors (ICIs). However, whether this relationship exists in non-small cell lung cancer (NSCLC) patients remains unclear. Thus, this meta-analysis was conducted to investigate the prognostic role of NLR and PLR in NSCLC treated with ICIs. Methods: Eligible studies that evaluated the value of pre-treatment or post-treatment NLR/PLR in NSCLC patients received ICIs were obtained by searching PubMed, Web of Science, Cochrane Library, and EMBASE. The pooled hazard ratio (HR) and 95% confidence interval (CI) were used to assess the relationship between NLR/PLR and overall survival (OS) and progression-free survival (PFS). Subgroup analysis and publication bias were conducted to investigate heterogeneity. Results: 1845 NSCLC patients from 21 studies were included and three ICIs(nivolumab, pembrolizumab, and atezolizumab) were used. Overall, high NLR was associated with poor OS (HR: 2.50, 95% CI:1.79-3.51, P < 0.001) and PFS (HR: 1.77, 95% CI:1.51-2.01, P < 0.001). Subgroup analyses were consistent with the pooled results. Similarly, the pooled results for PLR showed that elevated PLR was related to inferior OS (HR: 1.93, 95% CI: 1.51-2.01, P < 0.001) and PFS (HR: 1.57, 95%CI: 1.30-1.90, P < 0.001). However, the subgroup analysis based on test time indicated that there was no significant correlation between post-treatment PLR and survival outcomes. Conclusion: NLR and pre-treatment PLR could serve as prognostic biomarkers in NSCLC patients treated with ICIs. However, the value of post-treatment PLR needs further to be evaluated.