[Expression of pSTAT3 and PD-L1 in extranodal NK/T cell lymphoma and its clinical significance].

Objective: To study the expression of phosphates signal transducer and activator of transcription 3 (pSTAT3) and programmed death ligand-1 (PD-L1) in extranodal NK/T cell lymphomas (ENKTCL) and the relationships of pSTAT3 and PD-L1 expression with the clinicopathological characteristics and prognosis of ENKTCL. Methods: Fifty-one cases of ENKTCL diagnosed at Guangdong Provincial People's Hospital from June 2015 to February 2019 were included in the study. The expression of pSTAT3 and PD-L1 was examined using immunohistochemistry. Results: There were 35 males and 16 females, ranging from 18 to 85 years old with a median age of 47 years. The positive rates of pSTAT3 and PD-L1 expression were 68.6% (35/51) and 76.5% (39/51), respectively. pSTAT3 expression was correlated with PD-L1 expression (P=0.033,R=0.322), while there were no associations of pSTAT3 and PD-L1 expression with the clinicopathological characteristics of ENKTCL, including age, sex, clinical site, B symptom, Ann Arbor stage, LDH value, EBV DNA load of peripheral blood and international proliferation index score. Kaplan-Meier survival analysis showed the prognoses of the pSTAT3 and PD-L1 positive groups were slightly better than the respective negative groups, but the differences were not significantly (P>0.05). Conclusions: pSTAT3 is highly expressed in extranodal NK/T cell lymphoma and related to the expression of PD-L1, which provides a potential target and rationale for combinations of targeted therapies and immune checkpoint blockade inhibitors in the treatment of ENKTCL.