Prognostic and clinicopathological significance of neutrophil-to-lymphocyte ratio in patients with oral cancer

Objectives: Many studies have examined the prognostic significance of the neutrophil-to-lymphocyte ratio (NLR) in oral cancer; however, the results are contradictory. We, therefore, conducted a meta-analysis aiming to clarify the prognostic value of the NLR in oral cancer patients. Methods: A literature search was conducted in the PubMed, Web of Science, and Embase databases. Stata version 12.0 was used for statistical analysis. Results: A total of 14 studies with 3216 patients were finally included. The results indicated that a high NLR was significantly associated with worse DFS ( n =10, HR = 1.73, 95% confidence interval [CI] = 1.44-2.07, P <0.001). Similar results were observed for overall survival (OS) ( n =9, HR = 1.61, 95% CI = 1.39-1.86, P <0.001). Moreover, a high NLR was also correlated with lymph node metastasis ( n =7, odds ratio [OR] = 1.62, 95% CI = 1.32-1.98, P <0.001), advanced tumor stage ( n =7, OR = 2.63, 95% CI = 2.12-3.25, P <0.001), T stage ( n =6, OR = 3.22, 95% CI = 2.59-4.01, P <0.001), tumor differentiation ( n =5, OR = 1.48, 95% CI = 1.03-2.11, P =0.033), and perineural invasion ( n =4, OR = 1.83, 95% CI = 1.4-2.39, P <0.001). However, an elevated NLR was not correlated with gender. Conclusion: This meta-analysis showed that the NLR might be a potential independent prognostic factor in patients with oral cancer.