title: Programmed cell death ligand 1 (PD-L1) expression on gastric cancer and its relationship with clinicopathologic factors.
abstract: BACKGROUND
  Targeting the immune checkpoints in solid tumors becomes hot recently. Programmed cell death ligand 1 (PD-L1) is ligand for programmed death 1 (PD-1), which is known to negatively regulate T-cell activation. In the present study, we investigated the expression of PD-L1 in tumor specimens of gastric cancer and its relationships with clinicopathological variables and survival.
  
  
  METHODS
  The expression of PD-L1 in 132 surgically resected specimens of stage II and III gastric cancer was evaluated by immunohistochemistry in microarray tissue.
  
  
  RESULTS
  Expression of PD-L1 was observed in 50.8% (67/132) of gastric cancer tumor specimens. Patients whose tumor size over 5cm had a higher positive rate of PD-L1 expression. There was no relationship between the expression of PD-L1 and other clinicopathological variables including age, gender, clinical stage, location as well as histological differentiation. PD-L1 positive patients had significantly poorer survival than negative patients. The 5-year survival rates was 83.1% in those with PD-L1 negative patients and 50.7% for PD-L1 positive patients (P<0.001). The multivariate analysis indicated that both PD-L1 positive and Tumor-node-metastasis stage were independent prognostic factors in gastric cancer patients (P=0.001 and 0.025, respectively).
  
  
  CONCLUSIONS
  The expression of PD-L1 was found in half of stages II and III gastric cancer patients. Positive of PD-L1 expression indicated poor survival in Chinese stages II and III gastric adenocarcinoma patients. These results may provide the clue for immunotherapy in the adjuvant treatment setting of gastric cancer patients.
authors.affiliation: Department of Clinical Laboratory, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China ; Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine Baltimore, MD 21231, USA.
authors.forename: Miaozhen
authors.initials: M
authors.lastname: Qiu
authors.affiliation: Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Experimental Research, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Ji
authors.affiliation: Department of Experimental Research, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Baoxia
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Clinical Laboratory, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Xueping
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Pathology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Yan
authors.affiliation: Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Ruihua
authors.initials: R
authors.lastname: Xu
authors.affiliation: Department of Experimental Research, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine Guangzhou 510060, China.
authors.forename: Dajun
authors.initials: D
authors.lastname: Yang
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060890:B7-H1 Antigen / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D016009:Chi-Square Distribution; D002681:China; D005260:Female; D005743:Gastrectomy; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human
keywords: Clinicopathologic features; PD-L1; gastric cancer; prognosis