To clarify the prognostic value of the neutrophil to lymphocyte ratio (NLR) in oral squamous cell carcinoma (OSCC) patients.

The literature on the correlation between NLR and the prognosis and clinicopathological features of OSCC was searched in PubMed, Web of Science, Cochrane and Embase. The outcome indicators, including overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), tumor size, cervical lymph node metastasis, tumor stage, extracapsular lymph node invasion and peripheral nerve invasion, were analyzed by RevMan5.3 software.

In total, 6180 patients were included in 23 studies. The analysis showed that NLR was significantly negatively correlated with OS [HR=1.62, 95%CI(1.38, 1.91), P < 0.001], DFS [HR=1.48, 95%CI(1.24, 1.77), P < 0.001] and DSS [HR=1.87, 95%CI(1.60, 2.20), P < 0.001]. In addition, higher NLR values were positively correlated with tumor size [OR=2.68, 95%CI (1.84, 3.90), P < 0.001], cervical lymph node metastasis [OR=1.59, 95%CI (1.35, 1.88), P < 0.001], tumor stage [OR=2.85, 95%CI (2.35, 3.47), P < 0.001], extralymphatic invasion [OR=1.72, 95%CI (1.23, 2.40), P=0.001], and peripheral nerve invasion [OR=1.70, 95%CI (1.29, 2.24), P < 0.001]. However, there was no significant correlation with age [OR=0.96, 95%CI (0.71, 1.29), P=0.77], sex [OR=1.08, 95%CI (0.88, 1.33), P=0.55], or degree of differentiation [OR=1.15, 95%CI (0.92, 1.43), P=0.22].

Elevated NLR was significantly associated with the prognosis and clinicopathological features of OSCC and might be an independent prognostic factor.