title: Level of circulating PD-L1 expression in patients with advanced gastric cancer and its clinical implications.
abstract: OBJECTIVE
  The programmed cell death-1 receptor/programmed cell death-1 ligand (PD-1/PD-L1) pathway plays a crucial role in tumor evasion from host immunity. This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.
  
  
  METHODS
  Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study. Circulating PD-L1 expression was tested by enzyme-linked immunosorbent assay (ELISA). The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.
  
  
  RESULTS
  Expression of PD-L1 in advanced gastric cancer patients was significantly up-regulated compared with health people (P=0.006). The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis (P=0.026 and P=0.041, respectively). Although we didn't find significant difference in all advanced gastric cancer patients with different PD-L1 expression, the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients (65.6% vs. 44.7%, P=0.028).
  
  
  CONCLUSIONS
  PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Zhixue
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Zhaode
authors.initials: Z
authors.lastname: Bu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xijuan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Lianhai
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Aiwen
authors.initials: A
authors.lastname: Wu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xiaojiang
authors.initials: X
authors.lastname: Wu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Xing
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Du
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), 1 Department of Gastrointestinal Surgery, 2 Department of Central Laboratory, 3 Clinical Gastric Cancer Translational Research Laboratory, 4 Biological Tissue Bank, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Jiafu
authors.initials: J
authors.lastname: Ji
keywords: Programmed cell death-1 ligands (PD-L1); advanced gastric cancer; enzyme-linked immunosorbent assay (ELISA); tumor immunity