RESULTS OF CHEMOIMMUNOTHERAPY IN PATIENTS WITH GCB-SUBTYPE DIFFUSE B-CELL NON-HODGKIN LYMPHOMA

The classification of diffuse B-cell lymphoma (DBCL) into subtypes based on molecular features has important prognostic value. Moreover, the best response to standard R-CHOP therapy is observed in GCB subtype, but some patients with a favorable profile demonstrate resistance to standard R-CHOP therapy and recurrence of the disease. In this regard, we have developed a treatment program for patients with GCB-subtype DBCL, based on early assessment of the metabolic response to therapy and change of the treatment regimen. The aim of the present study was to investigate immediate and long-term results of treatment in the specified subgroup of patients with DBCL. Material and methods. The prospective study enrolled 23 patients treated at N. N. Alexandrov National Cancer Centre of Belarus in the period of 2020-2022. At the first stage all patients underwent two courses of chemoimmunotherapy according to the R-CHOP+interleukin-2 (IL-2) scheme followed by positron emission tomography with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG-PET/CT). In the presence of a complete metabolic response (CMR) patients with stage I-II disease underwent 2 more courses of R-CHOP + IL-2; in those with stage III-IV of the disease 4 courses of R-CHOP + IL-2 were conducted, followed by dynamic monitoring. In the absence of CMR, 4 courses of R-DA-EPOCH + IL-2 were performed, followed by FDG-PET/CT after the end of treatment. Results. After 2 courses of R-CHOP + IL-2, CMR was achieved in 20 (87.0%) patients, 3 (13.0%) patients did not show a complete response, and therefore the treatment regimen was changed. Among them, after 4 courses of R-DA-EPOCH + IL-2 CMR was recorded in all patients. The median follow-up was 20.8 months. During this period, progression of the disease was recorded in one patient, who subsequently died. The 3-year progression-free survival rate in the overall cohort was 93.3±6.4% (median survival was not achieved), and the overall survival rate amounted to 91.6±7.9%. Conclusions. Our findings support the literature data on the high rate of GCB-subtype response to R-CHOP therapy, and early change of treatment regimen depending on FDG-PET/CT results allows achieving satisfactory treatment results.