The pooled results showed that PD-L1 expression was increased in male (OR = 1.46, 95%CI: 1.24–1.71, P < 0.001), smoker (OR = 1.57, 95% CI: 1.28–1.93, P < 0.001), patients with SCC (OR = 1.59, 95% CI: 1.11–2.26, P = 0.01), a higher histological grade (OR = 2.55, 95% CI: 2.05–3.19, P < 0.001), larger tumor sizes (OR = 1.70, 95% CI: 1.29–2.25, P < 0.001), positive lymph nodal metastasis (OR = 1.34, 95% CI: 1.19–1.50, P < 0.001) and TNM stage (OR = 1.45, 95% CI: 1.18–1.78; P < 0.001). This evidence concerns the gene CD274 and neoplasm.