Prognostic significance of programmed death ligand-1 immunohistochemical expression in esophageal cancer: A meta-analysis of the literature

AbstractBackground:It is thought that expression of programmed death ligand-1 (PD-L1) in esophageal cancer (EC) might compromise patient survival. However, the association between PD-L1 expression and survival of patients with EC remains controversial.Methods:A meta-analysis combining eligible publi