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 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.
Limitations
This 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.