[Clinical characteristics of T-cell large granular lymphoblastic leukemia with STAT3 gene mutation]

Objective: This study aims to explore the clinical characteristics of T-cell large granular lymphocyte leukemia (T-LGLL) patients with STAT3 mutation status and provide a reference for clinical management of such patients. Methods: The clinical data of T-LGLL patients between 2009 and 2019 in Jiangsu Province Hospital were retrospectively analyzed. Differences in baseline clinical data, treatment responses, and survival outcomes in patients with STAT3 mutations or with no mutations were compared. Results: A total of 80 patients were included, including 66 patients without STAT3 mutation and 14 patients (17.5%) with STAT3 mutation. The frequency of Y640F mutation was the highest (42.9%) . Compared with non STAT3 mutation group, STAT3 mutation group had lower HGB (67.5 g/L vs 82.5 g/L, P=0.018) , lower neutrophil count (0.665×10(9)/L vs 1.465×10(9)/L, P<0.001) , higher LDH (229 U/L vs 198 U/L, P=0.041) , higher ferritin (402.5 g/L vs 236.0 g/L, P=0.029) , higher expression rate of TCR Vβ subfamily (89.2% vs 65.4%, P=0.014) and higher proportion of patients with treatment indications (100% vs 74%, P=0.033) . The complete remission rates of STAT3 mutation group and non mutation group were 38.5% and 32.7%, respectively, with no significant difference (P=0.748) . The overall response rate of first-line immunosuppressive therapy in STAT3 mutation group and non mutation group were 69.2% and 69.4%, respectively, with no significant difference (P=1.000) . The median follow-up time was 63 (2-121) months. There was no significant difference in the overall survival time between the two groups (P=0.170) . Conclusions: T-LGLL patients with STAT3 mutations seems to be correlated with an increased tumor burden and high treatment demand, and had a good response to first-line immunotherapies. The prognostic significance of STAT3 mutation in T-LGLL patients requires further validation.