title: Expression of programmed death-1 in cutaneous extranodal natural killer/T-cell lymphoma and its effect on clinical findings and biological behaviour.
abstract: BACKGROUND
  Recent studies have evaluated the expression of programmed death-1 (PD-1) and its prognostic value in malignant T-cell lymphomas.
  
  
  OBJECTIVE
  This study investigated whether the positivity of PD-1 was associated with the clinical characteristics of cutaneous extranodal NK/T-cell lymphoma (ENKTL) and evaluated its effects on survival outcomes.
  
  
  METHODS
  Forty-one patients with cutaneous ENKTL were included. Clinical features and survival outcomes were analysed according to the positivity of PD-1.
  
  
  RESULTS
  There was no significant difference between primary cutaneous ENKTL and secondary cutaneous ENKTL in the expression of PD-1. The degree of disease dissemination was not affected by the positivity of PD-1. Higher positivity for PD-1 was associated with lesions presenting erythematous to purpuric patches that are mainly composed of small tumour cells. Cutaneous ENKTL presenting nodular lesions had a significantly lower number of PD-1-positive infiltrating cells than those with other clinical morphologies. There was no significant effect of PD-1 expression on outcomes such as overall and progression-free survival.
  
  
  CONCLUSIONS
  This study used a retrospective design and had a small sample size.
  
  
  CONCLUSIONS
  Higher PD-1 positivity is associated with small-cell-predominant cutaneous ENKTL. However, PD-1 expression has no prognostic value in cutaneous ENKTL.
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Won
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: S E
authors.initials: SE
authors.lastname: Chang
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: M W
authors.initials: MW
authors.lastname: Lee
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: W J
authors.initials: WJ
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000378:metabolism*; D012878:Skin Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
chemical_list: C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor