Ukrainian prospective study in patients with T-cell non-Hodgkin lymphomas.

Background: T-cell lymphoma (TCL) is a heterogeneous group of lymphoproliferative diseases that account for 10-15% of all non-Hodgkin lymphomas. The aim of the study was to analyze the incidence of TCL in Ukraine, distribution according to subtypes and to assess the results of treatment of patients with TCL depending on lymphoma subtype and clinical-and-laboratory risk factors.

Patients and methods: Data from 70 patients with TCL were analyzed from February 2018 to May 2021. T-cell lymphoid neoplasms were diagnosed according to the 2016 WHO classification. The patients were divided into 4 groups: 1^st (A) - leukemic forms (n = 13) (received SMILE or HyperCVAD +/- auto/alloSCT); 2^nd (B) - nodal T-cell lymphomas (n = 43) (CHOP-like regimens); 3^rd (C) - cutaneous T-cell lymphomas (n = 9) (PUVA therapy, interferon, and methotrexate); 4^th (D) - extranodal T-cell lymphomas (n = 5) (CHOP-like regimens). The response was determined according to the Lugano 2014 criteria.

Results: According to the study results, 5-6% of all non-Hodgkin lymphoma registered in Ukraine in 2018-2020 were T-cell lymphomas. The most common subtype was peripheral TCL (61%). In the studied groups of TCL patients, the overall response rate was 50% (n = 35). 2-years event-free survival rate was 62.27%. 2-years overall survival rate was 65.76%. 18-month progression-free and overall survival in group B was higher versus groups A, C and D. The factors of unfavorable prognosis were bone marrow involvement and the expression of Ki67 > 65% (p = 0.03 and p = 0.006, respectively).

Conclusions: Histologic subtype of T-cell non-Hodgkin lymphoma influence the treatment outcome. The best overall response rate, overall survival rate, progression-free survival were in group of patients with nodal T-cell non-Hodgkin lymphomas, the worst - in patients from leukemic group. Poor prognostic factors are bone marrow involvement, and Ki-67 expression > 65%.