Table 2.

Summary of the main findings of the current study

Evidence	Main findings
Prognostic value of PD‐L1	Current evidence does not support the role of PD‐L1 expression as a significant prognosticator for OSCC patients (HR for OS: 0.97, 95% CI: 0.53−1.80; HR for DFS: 0.83, 95% CI: 0.47−1.46).
Predictive value of PD‐L1	Trials support that PD‐L1 expression is associated with an increased objective response rate in patients with CPS ≥1, with better response with CPS value ≥20.
Limitations of studies available in the literature	High heterogeneity of studies in terms of PD‐L1 clone and platform used.
	Different scoring systems for defining positivity.
	Suboptimal investigation of effects of previous therapy on PD‐L1 expression.
Future directions	Standardization of clones and scoring systems to have more homogeneous data.
	Best selection of patients.
	Aid coming from artificial intelligence tools on digital slides to evaluate PD‐L1 expression.

Abbreviations: CI, confidence intervals; CPS, combined positive score; DFS, disease‐free survival; HR, hazard ratio; OS, overall survival; OSCC, oral squamous cell carcinoma; PD‐L1, programmed cell death‐ligand 1.