PD-1 expression is not a good prognostic marker for cutaneous ENKTL

In February, Y. J. Kim, from the Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, and colleagues published in the Journal of the European Academy of Dermatology and Venereology the results of a study investigating the potential use of Programmed Death-1 (PD-1) expression as a prognostic marker in cutaneous Extranodal Natural Killer/T-Cell Lymphoma (ENKTL).

Key highlights:

• Retrospective analysis of 41 ENKTL pts with biopsy confirmed cases at the Asan Medical Center between Jan 1998–Dec 2015, median age 45.2 years
• Immunohistochemical staining performed to assess PD-1 expression, where >10% cells being stained was classed as a positive case
• Primary cutaneous ENKTL = 24 pts
• Secondary cutaneous ENKTL = 17 pts
• Results:
  • Pts with PD-1-positive lesions = 53.7% (n=22)
  • No significant difference in PD-1 positivity between:
    • Disease stage (P = 0.205)
    • IPI scores (P = 0.397)
    • Primary and secondary cutaneous ENKTL (P = 0.233)
  • Overall median OS = 37 months (95% CI, 28.46–45.53 months)
    • PD-1-positive: median OS = 47 months
    • PD-1-negative: median OS = 36 months
  • Overall median PFS = 11 months (95% CI, 6.72–15.28 months)
    • PD-1-positive: median PFS = 12 months
    • PD-1-negative: median PFS = 8 months
  • No difference seen between PD-1 positive and negative ENKTL patients in median OS (P = 0.582) or PFS (P = 0.513)

In conclusion, the authors stated that PD-1 expression was shown to not have any prognostic value in cutaneous ENKTL, although this study was both retrospective and had a small sample size. Further prospective studies would need to be conducted to confirm these findings.

Abstract:

Background. Recent studies have evaluated the expression of programmed death-1 (PD-1) and its prognostic value in malignant T-cell lymphomas. Objectives. 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 analyzed 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 tumor 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. Limitations. The present study used a retrospective design and had a small sample size. Conclusion. Higher PD-1 positivity is associated with small-cell-predominant cutaneous ENKTL. However, PD-1 expression has no prognostic value in cutaneous ENKTL.