[Interim efficacy of a multicenter cohort study for China Net Childhood Lymphoma mature B-cell lymphoma 2017 regimen in the treatment of pediatric High-grade-B cell lymphoma].

To analyze the mid-term efficacy of the China Net Childhood Lymphoma mature B-cell lymphoma 2017 (CNCL-B-NHL-2017) regimen in treating children with high-grade B-cell lymphoma (HGBL). Clinical and pathological data of HGBL children aged≤18 years admitted to 16 hospitals of the Chinese Children's Lymphoma Collaborative Group (CNCL) from May 2017 to April 2021 were collected retrospectively. They were divided in to high-grade B-cell lymphoma with double hit/triple hit (HGBL-DH/TH) group and high-grade B-cell lymphoma non-specified (HGBL-NOS) group, according to the 2016 version of the World Health Organization (WHO) Hematopoietic and Lymphoid Tissues Cancer Classification. Both groups of patients were treated with stratified chemotherapy by risk according to the CNCL-B-NHL-2017 scheme. The deadline for follow-up was December 31, 2023. All the patients were examined by chromosome fluorescence in situ hybridization (FISH), and the rearrangement of genes MYC, BCL-2 and BCL-6 was confirmed. The clinical and pathological characteristics of patients at disease onset were analyzed, and the therapeutic effects of patients in different clinical stages and risk groups were compared. Survival analysis was drawn by Kaplan Meier method, the log-rank test was used to compare the differences in the cumulative survival rate between different groups, and multivariate Cox regression model was used to identify the prognostic factors. A total of 62 patients were included, with an onset age [(, )] of 7 (4, 11) years, including 48 males and 14 females. There were 11 (17.7%) patients in stageⅡ, 33(53.2%)patients in stage Ⅲ and 18(29.1%)patients in stage Ⅳ. FISH testing showed that 4 cases (6.5%) were HGBL-DH and 3 (4.8%) were HGBL-TH. The remaining 55 cases (88.7%) were HGBL-NOS, with 18 cases accompanied by MYC rearrangement. There were 7 cases in the HGBL-DH/TH group and 55 cases in the HGBL-NOS group. Thirteen cases (20.9%) were treated with the B1 regimen, 3 cases (4.8%) with B2 regimen, 37 cases (59.6%) with C1 regimen, and 9 cases (14.7%) with the C2 regimen. Forty-eight cases (77.4%) received rituximab therapy at the same time. Five cases (8.0%) progressed during treatment. The follow-up time [(, )] was 43.5 (36.1, 53.7) months. The complete remission rate was 91.9% (57/62). The 3 year overall survival rate was 93.5% and event-free survival (EFS) rate was 91.9%. The 3-year overall survival rate in the HGBL-NOS group was higher than that in the HGBL-DH/TH group (96.3% vs 71.4%, =0.011). The 3-year EFS rate of the HGBL-NOS group was higher than that of the HGBL-DH/TH group (94.5% vs 71.4%, =0.037). In the HGBL-NOS subgroup, the overall survival rate of children with MYC rearrangement was lower (100% vs 88.9%,=0.039). Multivariate Cox regression analysis showed that central invasion (=6.05, 95%: 1.96-38.13, =0.046) was a risk factor for overall survival. CNCL-B-NHL-2017 regimen shows significant effects in the treatment of pediatric HGBL, with a good prognosis.