Clinicopathological And Prognostic Significance Of Programmed Cell Death 1 Ligand 1 Expression In Patients With Esophageal Squamous Cell Carcinoma:A Meta-analysis

Objective:To evaluate the expression of programmed death-ligand 1(PD-L1)and their clinical and prognostic significance in esophageal squamous cell carcinoma(ESCC).Methods: A comprehensive literature search of electronic databases(PubMed,the Cochrane Library,Web of Science,CNKI,Wanfang data)was performed for relevant studies using multiple search strategies.The bias of data was analyzed by using RevMan5.3 software Results: A total of 3431 ESCC patients from six studies were included.The results indicated that the PD-L1 protein ′s high expression was leading to a poor overall survival rat.However,none of the clinicopathological characteristics was correlated with PD-L1 expression,including gender,tumor depth.status of lymph node metastasis.Conclusion:PD-L1 might be a poor prognostic biomarker for ESCC.Further large-scale research should be performed to reveal the precise clinicopathological and prognostic significance of PD-L1 in ESCC by unified testing standard.