Prognostic significance of pretreatment neutrophil-to-lymphocyte ratio in patients with laryngeal cancer: a systematic review and meta-analysis

Background The neutrophil-to-lymphocyte ratio (NLR) has been shown to be associated with the progression of laryngeal cancer (LC), but studies have reported inconsistent results. We systematically evaluated the effect of the pretreatment NLR on the prognosis of LC in the meta-analysis. Method The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched from January 1, 2000 to September 10, 2019, to identify studies investigating the relationship between the NLR and outcomes in LC patients. The fixed-effects model was used to assess the pooled hazard ratio (HR), along with the 95% confidence interval (95% CI). Results A total of 105 records were obtained through the databases and 12 studies enrolling 3710 patients were included in the meta-analysis. The pooled overall survival (OS, HR = 1.76, 95% CI 1.53-2.03,P < 0.001), progression-free survival (PFS, HR = 1.72, 95% CI 1.38-2.13,P < 0.001) and disease-free survival (DFS, HR = 1.66, 95% CI 1.33-2.07,P < 0.001) indicated that a higher NLR led to a poorer prognosis for patients with LC. In terms of publication year, country, cutoff value, cutoff method, treatment modality, statistical model and NOS score, subgroup analyses consistently showed a worse OS in patients with an elevated NLR. Additionally, there was no significant difference among the subgroups (allPfor heterogeneity > 0.05). Conclusion An elevated pretreatment NLR is significantly associated with poorer prognosis in patients with LC. NLR values are easily obtained from routinely collected blood samples and could assist clinicians in determining the prognosis of LC patients.