Objective:To explore the clinical characteristics and prognosis of children with chronic myeloid leukemia in the blast phase (CML-BP) .Methods:The clinical characteristics, treatment measures, and survival outcomes of 28 children with CML-BP were analyzed in our hospital from January 2008 to November 2022.Results:The male to female ratio of the 28 children with CML-BP was 1.15∶1. The median age of diagnosis of CML-BP was 10 years, and the median follow-up time was 79 months. During the diagnosis of CML, four children were in the BP, one was in the accelerated phase (AP) and 23 children were in the chronic phase (CP). Among the 23 children with CML-CP, 75% had progressed directly from CP to BP without experiencing the AP. Among the children diagnosed with CML-BP, 71.4% were classified as chronic myeloid leukemia lymphoid blast phase (CML-LBP), 25.0% belonged to the chronic myeloid leukemia myeloid blast phase (CML-MBP), and 3.6% belonged to the chronic myeloid leukemia mixed phenotype acute leukemia (CML-MPAL). Treatment with hemaopoietic stem cell transplantation (HSCT) after tyosine kinase inhibitor (TKI) combined with chemotherapy was administered to 19 children, two children received HSCT after TKI alone, and seven children received TKI combined with chemotherapy but without HSCT. The 5-year overall survival of the 28 children with CML-BP was 59.3%.Conclusion:The direct progression of BP from CP is greater in children with CML-BP compared with adults, and the overall prognosis of children with CML-BP is poor.

Background::The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with high-risk (HR) T-cell acute lymphoblastic leukemia (T-ALL) in first complete remission (CR1) is still under evaluation. Moreover, relapse is the main factor affecting survival. This study aimed to explore the effect of allo-HSCT (especially haploidentical HSCT [haplo-HSCT]) on improving survival and reducing relapse for HR childhood T-ALL in CR1 and the prognostic factors of childhood T-ALL in order to identify who could benefit from HSCT.Methods::A total of 74 newly diagnosed pediatric T-ALL patients between January 1, 2012 and June 30, 2018 were enrolled in this retrospective study. Patients were stratified into the low-risk chemotherapy cohort ( n = 16), HR chemotherapy cohort ( n = 31), and HR transplant cohort ( n = 27). Characteristics, survival outcomes, and prognostic factors of all patients were then analyzed. Results::Patient prognosis in the HR chemotherapy cohort was significantly worse than that in the low-risk chemotherapy cohort (5-year overall survival [OS]: 58.5% vs. 100%, P = 0.003; 5-year event-free survival [EFS]: 54.1% vs. 83.4%, P = 0.010; 5-year cumulative incidence of relapse [CIR]: 45.2% vs. 6.3%, P = 0.011). In HR patients, allo-HSCT improved the 5-year EFS and CIR compared to that of chemotherapy (5-year EFS: 80.1% vs. 54.1%, P = 0.041; 5-year CIR: 11.6% vs. 45.2%, P = 0.006). The 5-year OS was higher in the HR transplant cohort than that in the HR chemotherapy cohort (81.0% vs. 58.5%, P = 0.084). Minimal residual disease re-emergence was an independent risk factor for 5-year OS, EFS, and CIR; age ≥10 years was an independent risk factor for OS and EFS; and high white blood cell count was an independent risk factor for EFS and CIR. Conclusion::Allo-HSCT, especially haplo-HSCT, could effectively reduce relapse of children with HR T-ALL in CR1.

Objective:To explore the molecular response and prognostic factors of pediatric patients with Ph-positive acute lymphoblastic leukemia (Ph + ALL) treated by tyrosine kinase inhibitors (TKI) with chemotherapy in TKI era. Methods:The clinical data of children newly diagnosed with Ph + ALL admitted at Department of Pediatrics, Peking University People′s Hospital from August 2006 to February 2017 were retrospectively reviewed.The molecular biological characteristics and survival prognosis of the 30 patients who received continuous TKI with chemotherapy from early induction combined and no subsequent transplantation were analyzed. Results:The 30 patients with Ph + ALL had 19 males and 11 females with a median age of 8-year-old (ranging from 2 to 16 years). The complete remission (CR) rate after the first cycle of induction chemotherapy was 96.7% (29/30 cases), with overall CR rate of 100.0%; Before treatment, the mean level of BCR/ ABL mRNA in the 30 patients was 73.2% (0.12%-160.60%) and the level declined significantly with the progression of chemotherapy courses, reaching the plateau stage at the 6 th month of chemotherapy ( Z=-1.922, P>0.05); nine patients had recurrence, with a median recurrence time of 7 months (3.7-58.8 months). Univariate analysis showed that age ( P<0.05), the lever of minimal residual disease (MRD) after induction chemotherapy ( P<0.01) and the MRD level at the 3 th month of induction chemotherapy ( P<0.01) affected the recurrence rate.The median follow-up time of 30 patients was 42.6 months (6.4-96.5 months), and the 3-year overall survival (OS) rate and event-free survival (EFS) rate were (78.6±7.8)% and (72.4±8.4)%, respectively; Cox multivariate analysis showed that the initial white blood cell count ≥34.0×10 9/L ( OR=11.955, 95% CI: 1.075-132.899, P<0.05) and BCR/ ABL mRNA reduction less than 3 log from baseline [major molecular response (MMR)] at the 3 th month of induction chemotherapy ( OR=8.563, 95% CI: 1.254-58.478, P<0.05) were independent risk factors affecting the 3-year EFS rate.In addition, the initial white blood cell count ≥34.0×10 9/L ( OR=14.327, 95% CI: 1.843-243.592, P<0.05) was also an independent risk factor affecting the 3-year OS rate. Conclusions:The application of TKI can significantly deepen the molecular response of Ph + ALL in children.In the TKI era, the initial white blood cell count ≥ 34.0×10 9/L and BCR/ ABL mRNA reduction less than 3 log from baseline (MMR) at the 3 th month of induction chemotherapy are independent risk factors for the long-term survival of pediatric Ph + ALL.

Objective: To evaluate the safety and efficacy of chimeric antigen receptors T cells (CAR-T) in childhood acute B lymphoblastic leukemia (B-ALL) to probe the prognosis-related factors. Methods: Forty-eight children, 29 boys and 19 girls, aged 3-17years old (median age was 8 years old) , with recurrent or refractory CD19 positive B-ALL, were treated by the CD19 specific CAR-T cells. A total of 48 cases received 61 infusions. Flow cytometry or real-time quantitative polymerase chain reaction method were used to monitor micro residual disease (MRD) . The follow-up period was from 16 to 1 259 days with the median follow-up of 406 days. SPSS software was used to statistical analysis. Results: No adverse reaction was observed during 61 infusions. The most common adverse reaction after CAR-T cell infusions was cytokine-release syndrome (CRS) . Only 2 cases experienced level 3 CRS performance, including continuous high fever, convulsions, delirium, serous cavity effusion, and decreasing of blood pressure. Tocilizumab was given to release CRS performance. No treatment-related death occurred. Thirty-seven patients showed response during 7 to 28 days after infusions. The early response rate was 77.1%, with MRD before infusion less than 5% group higher than the MRD more than 5% group (87.1% vs 58.8%, χ²=4.968, P=0.036) . For the 37 patients who showed response to CAR-T cell infusions, univariate analysis identified that age, disease status at the time of treatment, MRD before infusion affected 2-year OS rate (P<0.05) . Multivariate prognostic analysis for EFS disclosed that the MRD before infusion more than 5% (RR=3.433, 95% CI 1.333-8.844, P=0.011) and not bridge to HSCT (RR=4.996, 95% CI 1.852-13.474, P=0.001) were the independent risk factors. Conclusion The fourth generation CAR-T cells directed against CD19 could effectively and safely treat relapsed and refractory B-ALL, which implicated that CAR-T therapy as a novel therapeutic approach could be useful for patients with relapsed or refractory B-ALL who have failed all other treatment options. Reducing MRD as far as possible by effective pretreatment chemotherapy was in favor of increasing the response rate. Bridging HSCT after CAR-T cell treatment might be a better therapeutic strategy for the patient with refractory or molecular relapsed B-ALL.

Objective: To analyze the clinical outcome and the prognostic factor in pediatric patients with core binding factor-acute myeloid leukemia (CBF-AML). Methods: A total of 121 newly diagnosed pediatric CBF-AML patients enrolled from Aug. 2005 to Sep. 2017 were retrospectively reviewed. Cumulative incidence of relapse (CIR), event-free survival (EFS) and overall survival (OS) rates were estimated by Kaplan-Meier method and prognostic factors were evaluated by Cox regression with SPSS. Results: Of the 121 patients, 120 patients were assessed for bone marrow remission after induction chemotherapy. 100 cases (83.3%) achieved complete remission (CR) after the first course of chemotherapy. 119 cases (99.2%) achieved CR after the second course of chemotherapy. Of the 121 patients, 13 patients (10.7%) had recurrence with the median interval of recurrence as 13.8 months (3.7 to 58.8 months). 17 patients (14.0%) died. The CIR, EFS and OS at 3 years were 12.7%, 77.5% and 82.8%, respectively. The factors including age at diagnosis, sex, initial WBC count, presence of extramedullary leukemia, C-KIT expression, additional chromosomal abnormalities, and CR after the first course of chemotherapy were analyzed by multivariate regression analysis of Cox. Multivariate analysis identified that additional chromosomal abnormalities was the only independent risk factor affecting OS (HR=4.289, 95%CI 1.070-17.183, P=0.040). Conclusions Pediatric CBF-AML was a unique setting of prognostic subtypes. Chemotherapy produced good responses. Additional chromosomal abnormalities was the only independent risk factor for OS in pediatric CBF-AML.

Objective: To explore the clinical features and prognostic factors of Ph-positive and/or BCR-ABL positive acute lymphoblastic leukemia (Ph⁺ ALL) in children. Methods: The clinical data of 68 Ph⁺ ALL children who were treated at Peking University People's Hospital from December 2006 to December 2016 was retrospectively reviewed. Survival analysis were estimated by Kaplan-Meier method. Univariate analysis was estimated by Log-rank test and Chi-square, and multivariate analysis was estimated by Cox proportional hazards regression model. Results: In the 68 cases, the proportion of male to female was 2.1∶1, with a median age of 8 (1-16) years, and the median overall survival (OS) and disease free survival (DFS) were 16.8 months and 13.5 months, respectively. The early response rate to treatment was 43.9%, with myeloid-antigens-expression group lower than the non-expression group (29.6% vs 61.3%, χ²=5.814, P=0.020); The complete remission (CR) rate after one-course induction therapy was 86.2% (56/65), with good-response group higher than the poor-response group (100.0% vs 74.2%, χ²=6.680, P=0.003);The CR rate after induction in patients receiving imatinib plus chemotherapy was higher than the patients receiving chemotherapy only (94.9% vs 73.1%, χ²=5.185, P=0.024). The 2-and 5-year OS were (61.4±7.0)% and (50.8±8.1)%, respectively. The 2-and 5-year DFS were (54.6±6.8)% and (48.6±7.3)%, respectively. Univariate analysis showed that the initial WBC, LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year OS rate (all P<0.05). LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year DFS rate (all P<0.05). Multivariate prognostic analysis for OS (RR=45.7, 95% CI 1.4-1 528.2, P=0.033) and DFS (RR=52.3, 95% CI 1.6-1 725.9, P=0.026) showed that the spleen ≥ 3 cm was the independent risk factor. Conclusions Pediatric Ph⁺ ALL is a special condition with unique clinical and biological features. The early response to treatment was poor in patients with myeloid-antigens-expression, which resulted in a low CR rate after one-course induction and the administration of imatinib can remarkably improve the CR rate. Initial spleen ≥ 3 cm is an independent prognostic factor. The efficacy of chemotherapy alone is poor, and imatinib combined with chemotherapy is applauded in the aim of improving outcomes.

Objective To explore the clinical characteristics and relevant factors affecting treatment and prognosis of TCF3-PBX1 positive acute lymphoblastic leukemia (ALL). Methods The clinical data of 29 children with newly diagnosed TCF3-PBX1 positive ALL from August 2006 to August 2015 were analyzed retrospectively. The expression level of TCF3-PXB1 fusion gene was monitored by regular quantitative reverse transcription polymerase chain reaction. The factors influencing prognosis in children with TCF3-PBX1 positive ALL were analyzed. Results There were 29 children (16 males and 13 females) with a median age of 8 years (9 months to 16 years). The most common immunophenotype was pre-B cell type (pre-B) (58.6％). The karyotype analysis showed that unbalanced translocation was more common (41.4％). The complete remission rate was 100％ on thirty-third day in 29 children, but the minimal residual disease (MRD) was not completely negative. Three cases were relapsed, all of whom were MRD positive. Cox multivariate regression analysis showed that age was an independent risk factor for 5 year overall survival (P<0.05). The 5 year overall survival rate and disease-free survival rate were (82±8)％ and (81±7)％respectively. Conclusions Childhood TCF3-PBX1 positive ALL is a highly heterogeneous disease with high rate of complete remission and good long-term efficacy. The risk stratification and individualized treatment is the key to improve the cure rate.

Objective To summarize the clinical and biological characteristics and to analyze the prognosis of childhood lymphoma. Methods Clinical data of 60 patients diagnosed as lymphoma during the past ten years were retrospectively studied. All cases were classified according to the WHO classification criteria of lymphoma and the St. Jude staging system. Results Of all the 60 patients, the ratio of male to female was 2.5: 1. The median age was 8 years old (range from 6 months to 15 years). Localized mass was the most common chief complaint for first consultation accounting for 35.0%. The proportion of the bone marrow and central nervous system involvement was 63.3% and 6.7%, respectively. Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) counted for 8.3% and 91.7%, respectively. All HL were classified as CHL. As to NHL, LBL, BL/B-ALL, ALCL, and DLBCL were the main types. According to St. Jude staging, the advanced stage accounted for 95.0%. There were 8 cases with progressive disease/relapse with median time of 14 months (ranged from 6 months to 84 months). 6. In all patients,the 5-year anticipated overall survival(OS)rate was(78%±6%);the 5-year OS for HL and NHL were 100% vs(76%±8%). The survival rate of the two groups showed no significant difference (P=0.270). Cox multivariate analysis indicated that sex (P=0.038) was independent prognostic factors. Conclusions Pediatric lymphoma occurred more in male than in female, peaked at school age. The main histologic type was NHL. Most patients were diagnosed as advanced stage. By gender, female is a poor factor that affects prognosis.

Objective To explore the prognostic value of quantitative monitoring of RUNX1-RUNX1T1 fusion gene in pediatric t(8;21)/RUNX1-RUNX1T1 positive acute myeloid leukemia(AML).Methods A total of 81 new-ly diagnosed AML children with t(8;21)/RUNX1-RUNX1T1 positive were enrolled in the People′s Hospital,Peking University,between August 2005 and January 2016.RUNX1-RUNX1T1 gene copy number of all the patients was analyzed by real-time quantitative PCR(qPCR)technology at diagnosis and after therapy in all patients.Cumulative incidence of relapse rate(CIR),event-free survival(EFS)rate and overall survival(OS)rate were estimated by Ka-plan-Meier method and prognostic factors were evaluated by COX regression. Results The level of RUNX1-RUNX1T1 gene on diagnosis was used as the baseline to determine whether the level of gene after treatment had a more than 3 logarithmic(3 log)reduction.After 2 courses of induction therapy,the patients with a more than 3 log reduction of RUNX1-RUNX1T1 transcript levels(≥3 log)had better EFS rate(82.4% vs.57.6%,χ2=7.454,P<0.01),and better OS(93.6% vs.59.3%,χ2=9.703,P<0.01),compared to the patients with a less than 3 log reduction(<3 log).Multivariate analysis showed that 3 log reduction in RUNX1-RUNX1T1 transcript levels after 2 courses of in-duction therapy was an independent prognostic factor for EFS rate[hazard ratio(HR)=4.223,95% confidence interval (CI):1.507-11.836,P<0.01]and OS rate(HR=5.002,95%CI:1.282-19.516,P<0.05).When periodically monitoring the RUNX1-RUNX1T1 gene,63 out of the 81 children patients were monitored for more than 6 times.The patients who had a more than 3 log reduction of gene before,but then those whose gene transcript level rose more than 1 log level were divided into group A,and the remaining patients were divided group B,and the difference of CIR was statistically significant between group A and group B(46. 7% vs. 4. 7%,P <0. 01). Conclusions RUNX1-RUNX1T1 gene copy number was detected with qPCR method in pediatric t(8;21)/RUNX1-RUNX1T1 positive AML,which can determine the treatment effect,predict the recurrence of patients and assess long-term prognosis.Thus it has great clinical application value.

OBJECTIVETo evaluate the safety and efficacy of chimeric antigen receptors T cells (CAR-T) in childhood acute B lymphoblastic leukemia (B-ALL).

METHODSA relapsed B-ALL child after allogeneic hematopoietic stem cell transplantation (allo-HSCT) was treated with CAR-T, and the related literatures were reviewed.

RESULTAn 11-year-old girl with TEL-AML1 fusion gene positive BALL who suffered a bone marrow relapse 28 months after remission from conventional chemotherapy. During the second remission, the patient received haploidentical allo-HSCT. She relapsed with detectable TEL-AML1 fusion gene even after chemotherapy and donor leukocyte infusions. She received an experimental donor-derived fourth generation CD19 CAR-T therapy. After infusion of 1 × 10(6)/kg CAR-T cells, she experienced only mild or moderate cytokine-release syndrome and the minimal residual disease turned negative. Then three maintenance of CAR-T cell infusions [(0.83-1.65)×10(6)/kg] was administered, and the disease-free survival had lasted for 10 months. However, the TEL-AML1 copies in her blood still increased and she died with leukemia relapse after additional CAR-T cell infusion.

CONCLUSIONTreatment of relapsed B-ALL with the fourth generation CAR-T cells directed against CD19 was effective and safe. CAR-T therapy is a novel therapeutic approach that could be useful for patients with relapsed and refractory B-ALL who have failed all other treatment options.

Bone Marrow ; Child ; Core Binding Factor Alpha 2 Subunit ; genetics ; Disease-Free Survival ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Neoplasm, Residual ; Oncogene Proteins, Fusion ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; therapy ; Receptors, Antigen, T-Cell ; genetics ; Recurrence ; Remission Induction ; T-Lymphocytes ; cytology ; Transplantation, Homologous