title: Significance of Programmed Death Ligand 1 (PD-L1) Immunohistochemical Expression in Colorectal Cancer.
abstract: BACKGROUND
  The significance of programmed death ligand 1 (PD-L1) expression in the prognosis of patients with colorectal cancer remains to be determined.
  
  
  METHODS
  We assessed the levels of PD-L1 expression in tumor-infiltrating immune cells as well as tumor cells, and evaluated the association between PD-L1 expression and clinical outcome in 262 colorectal cancer patients.
  
  
  RESULTS
  In univariate analysis, TNM stage (p < 0.001), PD-L1 expression in tumor-infiltrating immune cells (p = 0.016), tumor location (p = 0.033), and tumor size (p = 0.019) were associated with survival. In multivariate analysis, PD-L1 expression in tumor infiltrating immune cells and TNM stage were independent prognostic factors (HR 1.83, 95 % CI 1.09-3.05, p = 0.021; HR 2.49, 95 % CI 1.51-4.12, p < 0.001, respectively). Eight percent of patients had positive PD-L1 expression in tumor cells. In contrast, PD-L1 expression in tumor cells was not significantly associated with patient clinical outcome.
  
  
  CONCLUSIONS
  Our data indicate that PD-L1 status in tumor-infiltrating immune cells is a significant prognostic factor in colorectal cancer patients. There is a need for randomized studies that evaluate the role of PD-L1 expression in colorectal cancer in treatment decision protocols for novel immunotherapy.
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China. wlisha@med.umich.edu.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China. wlisha@med.umich.edu.|Michigan Center for Translational Pathology, University of Michigan, 1400 E. Medical Center Drive, Ann Arbor, MI, 48109, USA. wlisha@med.umich.edu.
authors.forename: Lisha
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Ren
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 350 West 11th Street, Indianapolis, IN, 46202, USA.
authors.forename: Lee Ann
authors.initials: LA
authors.lastname: Baldridge
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 350 West 11th Street, Indianapolis, IN, 46202, USA.
authors.forename: M Francesca
authors.initials: MF
authors.lastname: Monn
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 350 West 11th Street, Indianapolis, IN, 46202, USA.
authors.forename: Kurt W
authors.initials: KW
authors.lastname: Fisher
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
authors.forename: Weiqi
authors.initials: W
authors.lastname: Sheng
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 350 West 11th Street, Indianapolis, IN, 46202, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D060890:B7-H1 Antigen / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016019:Survival Analysis; D046888:Tissue Array Analysis / Q000379:methods
chemical_list: D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human