Relationship of programmed death ligand-1 expression with clinicopathological features and prognosis in patients with oral squamous cell carcinoma: A meta-analysis

Abstract

BackgroundProgrammed death ligand-1 (PD-L1) expression is related to the prognosis of many solid tumors; however, its prognostic value in oral squamous cell carcinoma (OSCC) remains unclear. Here, a meta-analysis was performed to estimate the association of PD-L1 expression with prognosis and clinicopathological features in patients with OSCC. MethodsPubMed, Web of Science, EMBASE, Cochrane Library, and CNKI databases were searched to find relevant studies for identification of the association of PD-L1 expression with clinicopathological features and overall survival (OS) in patients with OSCC. The strength of the association of PD-L1 expression with clinicopathological features and OS in patients with OSCC was assessed according to the relative risk (RR), hazard ratio (HR), and 95% confidence interval CI (CI). ResultTwenty-three studies (including 3217 patients with OSCC) were evaluated. The meta-analysis showed that positive PD-L1 expression was significantly correlated with OS in patients with OSCC (HR = 1.00, 95% CI = 0.76–1.30, p = 0.284). Positive PD-L1 expression was significantly correlated with sex (RR = 1.22, 95% CI = 1.07–1.38, p = 0.002), histological differentiation (RR = 1.15, 95% CI = 1.02–1.30, p = 0.020), distant metastasis (RR = 0.68, 95% CI = 0.54–0.86, p = 0.011), lymph node metastasis status (RR = 0.83, 95% CI = 0.76–0.91, p < 0.001), TNM stage (RR = 0.81, 95% CI = 0.73–0.89, p < 0.001), and human papilloma virus infection status (RR = 1.30, 95% CI = 1.04–1.62, p = 0.019), but was not correlated with T stage and tumor recurrence. ConclusionHigh PD-L1 expression in OSCC was not related to OS. However, high PD-L1 expression was significantly related to certain clinicopathological features. Thus, positive PD-L1 expression may be a biomarker of poor prognosis in patients with OSCC.