title: PD-L1 expression in papillary renal cell carcinoma.
abstract: BACKGROUND
  The immune escape or tolerance of cancer cells is considered to be closely involved in cancer progression. Programmed death-1 (PD-1) is an inhibitory receptor expressed on activating T cells, and several types of cancer cells were found to express PD-1 ligand 1 (PD-L1) and ligand 2 (PD-L2).
  
  
  METHODS
  In the present study, we investigated PD-L1/2 expression in papillary renal cell carcinoma (pRCC).
  
  
  RESULTS
  We found PD-L1 expression in 29 of 102 cases, but no PD-L2 expression was seen. PD-L1 expression was not significantly correlated with any clinicopathological factor, including progression-free survival and overall survival. The frequency of PD-L1-positive cases was higher in type 2 (36%) than in type 1 (22%) pRCC; however, there was no significant difference in the percentages of score 0 cases (p value = 0.084 in Chi-square test). The frequency of high PD-L1 expression cases was higher in type 2 (23%) than in type 1 (11%), and the frequency of high PD-L1 expression cases was higher in grade 3/4 (21%) than in grade 1/2 (13%). However, no significant association was found between PD-L1 expression and all clinicopathological factors in pRCC.
  
  
  CONCLUSIONS
  High expression of PD-L1 in cancer cells was potentially associated to highly histological grade of malignancy in pRCC. The evaluation of the PD-L1 protein might still be useful for predicting the efficacy of anti-cancer immunotherapy using immuno-checkpoint inhibitors, however, not be useful for predicting the clinical prognosis.
authors.affiliation: Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.|Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Motoshima
authors.affiliation: Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-8556, Japan. ycomo@kumamoto-u.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Komohara
authors.affiliation: Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.
authors.forename: Chaoya
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.|Department of Anatomy Histology, Faculty of Medicine Airlangga University, Surabaya, Indonesia.
authors.forename: Arni Kusuma
authors.initials: AK
authors.lastname: Dewi
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Sohsuke
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Department of Urology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Kitada
authors.affiliation: Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kawano
authors.affiliation: Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Takahashi
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.|Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Sugimoto
authors.affiliation: Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Takeya
authors.affiliation: Department of Urology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Fujimoto
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.|Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Eto
mesh_terms: D000368:Aged; D060890:B7-H1 Antigen / Q000096:biosynthesis*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D012189:Retrospective Studies
chemical_list: D060890:B7-H1 Antigen