Prognostic significance of the neutrophil-to-lymphocyte ratio in peripheral T-cell lymphoma: a meta-analysis

The neutrophil-to-lymphocyte ratio (NLR) as an inflammatory marker may represent changes between inflammation and host immunity that affect the prognosis of peripheral T-cell lymphoma (PTCL). To comprehensively evaluate the NLR in PTCL, we performed a meta-analysis to investigate the relationship between the NLR and overall survival (OS) and progression-free survival (PFS). PubMed, Embase, Cochrane library, and China National Knowledge Infrastructure (CNKI) were searched for all relevant studies. Hazard ratios (HRs) and 95% confidence intervals (CIs) were obtained from each study. Heterogeneity among the included studies was checked to determine whether fixed or random effects model was used. In total, 8 studies with 921 patients were included for the meta-analysis. High NLR significantly correlated with worse OS (HR = 2.20, 95% CI 1.71–2.83, P < 0.05) regardless of region (Asian or non-Asian), sample size (< 60 or ≥ 60), median age (< 60 or ≥ 60), disease type, or cut-off value (NLR < 3.9 or NLR ≥ 3.9). In terms of PFS, the NLR had no prognostic impact for patients with PTCL (HR = 1.12, 95% CI 0.57–2.20, P = 0.742). Our findings suggest that PTCL patients with high NLR are more likely to have worse OS compared to those with low NLR. Therefore, the NLR can serve as a prognostic marker in PTCL.