Prognostic Value of Pretreatment Lymphocyte-to-Monocyte Ratio in Non-Small Cell Lung Cancer: A Meta-Analysis.

Past evidence has shown that lymphocyte-to-monocyte ratio (LMR) could be considered as a potential prognostic factor in non-small cell lung cancer (NSCLC). We conducted the current meta-analysis based on published studies to elucidate the prognostic value of pretreatment LMR on survival outcomes in NSCLC. Comprehensive searches of available electronic databases were implemented to identify potentially related studies that focused on the role of pretreatment LMR in predicting the prognosis of NSCLC patients. The hazard ratios (HRs) with 95% confidence intervals (CIs) were combined to assess the association of pretreatment LMR with overall survival (OS) and progression-free survival (PFS). A total of 20 articles including 8,304 patients were analyzed. Compared with patients with higher LMR, patients with lower LMR had poorer OS (HR = 1.63, 95% CI: 1.44-1.85, p < 0.001) and PFS (HR = 1.49, 95% CI: 1.25-1.77, p < 0.001). The subgroup analysis outcomes were similar to the overall analysis. Pretreatment LMR may be a useful prognostic marker in patients with NSCLC. However, more well-designed studies are warranted to confirm our findings.