title: An Immunohistochemical Analysis of PD-L1 Protein Expression in Surgically Resected Small Cell Lung Cancer Using Different Antibodies and Criteria.
abstract: BACKGROUND
  Programmed cell death ligand 1 (PD-L1) expression in lung cancer appears to be important in immunotherapy, as its expression can predict responses to programmed cell death-1 (PD-1)-blocking antibodies. However, a definitive antibody and cut-off value for PD-L1 expression are urgently needed.
  
  
  METHODS
  The PD-L1 expression in 40 surgically resected small cell lung cancer (SCLC) specimens was evaluated by immunohistochemistry (IHC) with three different antibodies: clones E1L3N, 28-8, and SP142, and using three different evaluations: the Allred score, 1% cut-off, and 5% cut-off.
  
  
  RESULTS
  The percentage of tumors with positive PD-L1 expression was inconsistent in the IHC evaluations using the Allred score and 1% cut-off. However, the IHC evaluations using the 5% cut-off showed similar rates of expression using the three different antibodies.
  
  
  CONCLUSIONS
  The results of this study provided detailed evidence on the frequency of PD-L1 expression in surgically resected SCLC, which may be a useful reference for identifying patients with PD-L1-expressing SCLC.
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Takada
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan gouji104kawa@gmail.com.
authors.forename: Gouji
authors.initials: G
authors.lastname: Toyokawa
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Okamoto
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takaki
authors.initials: T
authors.lastname: Akamine
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shinkichi
authors.initials: S
authors.lastname: Takamori
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Katsura
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Fujishita
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Shoji
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 Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
mesh_terms: D000906:Antibodies; D060890:B7-H1 Antigen / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000378:metabolism* / Q000473:pathology / Q000601:surgery
chemical_list: D000906:Antibodies; D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human
keywords: PD-L1; immunohistochemistry; small cell lung cancer