Childhood Acute Lymphoblastic Leukemia: Progress Through Collaboration

The mitochondria as an emerging target of self-renewal in T-cell acute lymphoblastic leukemia

Acute lymphocytic leukemia (ALL) is the most common leukemia in children, with the T-cell subtype (T-ALL) accounting for 15% of those cases. Despite advancements in the treatment of T-ALL, patients still face a dismal prognosis following their first relapse. Relapse can be attributed to the inability of chemotherapy agents to eradicate leukemia stem cells (LSC), which possess self-renewal capabilities and are responsible for the long-term maintenance of the disease. Mitochondria have been recognized as a therapeutic vulnerability for cancer stem cells, including LSCs. Mitocans have shown promise in T-ALL both in vitro and in vivo, with some currently in early-phase clinical trials. However, due to challenges in studying LSCs in T-ALL, our understanding of how mitochondrial function influences self-renewal remains limited. This review highlights the emerging literature on targeting mitochondria in diverse T-ALL models, emphasizing specific mitochondrial vulnerabilities linked to LSC self-renewal and their potential to significantly improve T-ALL treatment.

Psychosocial Outcomes in Parents of Children with Acute Lymphoblastic Leukaemia in Australia and New Zealand Through and Beyond Treatment

Background/Objectives: Parents of children with acute lymphoblastic leukaemia (ALL) experience emotional distress throughout their child's treatment course. This study describes the psychological experience of Australian and New Zealand parents of children diagnosed with ALL. Methods: This prospective, longitudinal study assessed distress, anxiety, depression, anger and the need for help in parents of children with newly diagnosed ALL across eight sites between October 2018 and November 2022. Psychological symptoms were quantified using the Emotion Thermometer (ET) tool and Patient-Reported Outcome Measurement Information System (PROMIS) questionnaires. Participants were recruited within ninety days of chemotherapy commencement, with surveys distributed bimonthly thereafter. Results: One hundred and seventeen participants completed 327 survey responses spanning 0 to 62 months post-diagnosis. Parental distress peaked within the first 6 months and 40% of parents reported clinically significant symptoms across four or more domains as measured by our questionnaires. Anxiety was the most consistently elevated symptom, with over 50% of responses above the clinical cut-off. Depression and the need for help also peaked closer to diagnosis and declined over time. In contrast, anger remained stable, with 27% reporting clinically significant scores across all time points. Increased time since diagnosis was significantly associated with reductions in distress, anxiety and depression scores. Conclusions: Australian and New Zealand parents experience high levels of psychological distress within the first six months following their child's diagnosis of ALL. A notable minority continue to report elevated distress levels over time, identifying a need for improved psychological support for family wellbeing throughout the ALL treatment trajectory.

Deciphering IGH rearrangement complexity and detection strategies in acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia is a highly heterogeneous malignancy characterised by various genomic alterations that influence disease progression and therapeutic outcomes. Gene fusions involving the immunoglobulin heavy chain gene represent a complex and diverse category. These fusions often result in enhancer hijacking, upregulation of partner proto-oncogenes and contribute to leukemogenesis. This review highlights the mechanisms underlying IGH gene fusions, the critical role they play in ALL pathogenesis, and current detection technologies.

Educational outcomes school year nine in children treated for acute lymphoblastic leukemia: A nationwide registry-based study from Sweden

Acute lymphoblastic leukemia (ALL) constitutes approximately 25% of pediatric cancers, and with contemporary protocols, the 5-year survival rate is over 90%. Despite improved survival, neurocognitive impairments from treatment raise concerns. This registry study aimed to explore the impact of ALL treatment on educational outcomes from school year nine in Swedish children. A population-based cohort of 503 children diagnosed with ALL from 1990 to 2010 was identified from the Swedish Childhood Cancer Registry and matched with five controls each. Assessed variables were delayed graduation, high school eligibility, total merit value, school grades in Swedish, English, mathematics, and physical education, and results in national tests. Analyses were performed between cases and controls and by sex, age at diagnosis, and risk group. Our results showed that, compared to controls, cases had higher odds for delayed graduation, poorer results in physical education, and higher rates of absence in national tests in English and mathematics. Children in the standard-risk group (treated with first-line chemotherapy only) exhibited similar results to matched controls whereas children in the high-risk group (treated with cranial irradiation, hematological stem cell transplantation, or/and for ALL relapse and thus likely received also radiotherapy) had lower total merit value compared to controls. We conclude that Swedish children diagnosed with ALL between the years 1990-2010 mainly exhibited comparable educational outcomes to controls, although children in the high-risk group had lower results. These findings highlight the importance of evaluating especially children with high-risk ALL in order to identify those requiring educational support and for designing targeted interventions.

Computational flow cytometry immunophenotyping at diagnosis is unable to predict relapse in childhood B-cell Acute Lymphoblastic Leukemia

B-cell Acute Lymphoblastic Leukemia is the most prevalent form of childhood cancer, with approximately 15% of patients undergoing relapse after initial treatment. Further advancements depend on novel therapies and more precise risk stratification criteria. In the context of computational flow cytometry and machine learning, this paper aims to explore the potential prognostic value of flow cytometry data at diagnosis, a relatively unexplored direction for relapse prediction in this disease. To this end, we collected a dataset of 252 patients from three hospitals and implemented a comprehensive pipeline for multicenter data integration, feature extraction, and patient classification, comparing the results with existing algorithms from the literature. The analysis revealed no significant differences in immunophenotypic patterns between relapse and non-relapse patients and suggests the need for alternative approaches to handle flow cytometry data in relapse prediction.

Refining Risk Stratification for B-cell Precursor Adult Acute Lymphoblastic Leukemia Treated With a Pediatric-inspired Regimen by Combining IKZF1 Deletion and Minimal Residual Disease

INTRODUCTION

Minimal residual disease (MRD) is the most important prognostic factor for B-cell acute lymphoblastic leukemia (B-ALL) however nearly 20-30% of patients relapsed even when they achieved negative MRD, how to identify these patients is less addressed. In this study, we aimed to reassess the prognostic significance of MRD and IKZF1 in adult B-ALL patients receiving pediatric chemotherapy regimens.

METHODOLOGY

A total of 202 newly diagnosed adult patients with B-ALL treated at Nanfang Hospital between January 2016 and September 2020 were enrolled in the population-based protocol of the PDT-ALL-2016 trial (NCT03564470), a GRAALL-backbone, peg-aspargase-intensified, antimetabolite-based pediatric-inspired regimen therapy. The validation dataset COG-P9906, which includes complete gene expression profiles and clinical data for 190 samples, is accessible via the NCBI Gene Expression Omnibus (GEO) at the following link: (https://www.ncbi.nlm.nih.gov/geo/), under the accession code GSE11877.

MAIN FINDINGS

B-ALL patients were redefined as standard (MRD-negative and IKZF1wild-type), intermediate (MRD-positive or IKZF1 deletion), and high-risk (MRD-positive and IKZF1 deletion) groups by combining IKZF1 deletion status and MRD. In the PDT-ALL-2016 cohort, patients in the high- and intermediate-risk groups who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) exhibited significantly improved 5-year overall survival (OS), event-free survival (EFS), and lower cumulative incidence of relapse (CIR) compared to those who received chemotherapy alone. In the PDT-ALL-2016 cohort, no significant advantage was observed in the 5-year OS, EFS, and CIR of patients in the standard-risk group who received allo-HSCT compared to those who received chemotherapy.

DISCUSSION

Traditional risk factors, incorporating clinical and cytogenetic features, have been previously evaluated to stratify risks and guide treatment decisions. However, the prognostic strength of this stratified system is limited by the pediatric-inspired protocol background, making it difficult to identify patients with a high risk of relapse. Therefore, in the era of pediatric-inspired protocols, it is imperative to reassess traditional risk factors to identify patients at high risk of recurrence and mortality.In this study, we retrospectively evaluated the combination of MRD and IKZF1 to develop an efficient risk stratification tool for adult patients with B-ALL in the pediatric-inspired chemotherapy era. Moreover, allo-HSCT had distinct efficacy at different risk levels, which means that the decision to perform allo-HSCT may be well guided by this risk classification scheme.

CONCLUSION

In conclusion, based on our cohort study and validation cohort, we demonstrated that the combination of MRD and IKZF1 deletion allows for better risk stratification of adults with B-ALL and that allo-HSCT mitigates the poor prognosis of MRD+ and/or IKZF1del subgroups.

Outcomes and prognostic factors associated with relapse after haploidentical stem cell transplantation for paediatric T-cell acute lymphoblastic leukaemia

The outcomes are poor for paediatric patients with T-cell acute lymphoblastic leukaemia (T-ALL) who relapse after haematopoietic stem cell transplantation (HSCT). However, studies focusing on paediatric patients with T-ALL following haploidentical HSCT (haplo-HSCT) are limited. We retrospectively identified a consecutive cohort comprising of 128 paediatric T-ALL after haplo-HSCT from 2642 consecutive ALL patients between January 2010 and June 2022. The 2-year overall survival and leukaemia-free survival were 67.77% ± 4.21% and 66.34% ± 3.82%, respectively, and the cumulative incidence of relapse (CIR) and non-relapse mortality were 33.82% ± 0.70% and 12.65% ± 0.46% respectively. According to the multivariate Cox regression analysis, CD34 cells, minimal residual disease (MRD) ≥0.01% before HSCT, chronic graft-versus-host disease (cGvHD) and cytomegalovirus were associated with relapse (p < 0.05). To develop a scoring system for stratifying patients, we combined the variables and stratified them into low (0-2 points) and high (3, 4) groups. Consequently, the 2-year CIR in low and high groups were 23.76% ± 1.83% and 48.22% ± 2.42% (p = 0.009), respectively. Children with T-ALL have poor long-term survival, and haplo-HSCT is a potent and safe treatment; however, the incidence of relapse is high. Eliminating pre-HSCT MRD, guaranteeing sufficient CD34 cells infusion and the occurrence of cGvHD and cytomegalovirus reactivation may benefit from relapse.

Clinical Actionability of the NUDT15 *4 (p.R139H) Allele and Its Association With Hispanic Ethnicity

Nudix hydrolase 15 (NUDT15) deficiency is strongly associated with thiopurine-induced myelosuppression. Currently, testing for NUDT15 deficiency is based on the genotyping of the most frequent and clinically characterized no-function variants, that is, *2, *3 and *9. The Hispanic/Latino-predominant variant NUDT15 *4 (p.R139H) is classified as "uncertain function" by the Clinical Pharmacogenetics Implementation Consortium, because of insufficient data to ascertain its clinical actionability. In this study, we evaluated the association of NUDT15 *4 with mercaptopurine (6-MP) tolerance in a retrospective cohort of 1,399 patients with acute lymphoblastic leukemia (ALL) of diverse ancestries. All patients were wildtype for thiopurine methyltransferase gene. Patients were treated with 6-MP in the context of ALL frontline clinical trials. The tolerated dose of 6-MP was used to assess drug toxicity during the maintenance phase of ALL therapy. Patients with NUDT15 *1/*4 (n = 16, all of whom self-identified as Hispanic/Latino) tolerated a significantly lower dose of 6-MP than did those with NUDT15 *1/*1: median [interquartile range] of 39.0 [21.2-52.8] mg/m2, vs. 62.2 [47.9-71.6] mg/m2, P value < 0.001. No patient homozygous for *4 was detected. In a separate retrospective validation study, six patients were identified as having NUDT15 *1/*4 by routine clinical pharmacogenetics testing and tolerated a 6-MP median dose of 38.7 mg/m2 (IQR, 33.7-54.0), confirming the need for dose reduction attributed to the NUDT15 *4 variant. These results point to the need to include NUDT15 *4 in pharmacogenetics-guided thiopurine dosing algorithms.

Graft CD8+ T cells for improving event-free survival after T cell-replete haploidentical stem cell transplantation in children with hematological malignancies

T cell-replete haploidentical hematopoietic stem cell transplantation (TCR-haplo-HSCT) is a potentially curative therapy for pediatric intractable hematological malignancies due to its graft-versus-leukemia efficacy. This single-center cohort study examined the effects of graft composition (T cell type and dose) on pediatric TCR-haplo-HSCT outcomes in 32 children with relapsed/intractable hematological malignancies. Graft T cell composition was classified using flow cytometry. High graft CD8+ T cell doses reduced disease relapse and improved overall survival and event-free survival, but did not increase transplant-related mortality and the incidence of grade III/IV acute graft-versus-host disease. Doses of grafted CD3+, CD4+, and CD34+ T cells did not affect patient outcomes. Children with differing event-free survival times were divided by a graft CD8+ T cell dose cut-off of 2.03 × 108 kg-1. These findings revealed that grafted CD8+ T cells improved the graft-versus-leukemia effect of pediatric TCR-haplo-HSCT without increasing the risk of transplant-related mortality.

Comparison of Capizzi and High-dose Methotrexate Approaches in the Treatment of Pediatric B-cell Acute Lymphoblastic Leukemia

Childhood cancers, with leukemia at the forefront, comprise 97% acute leukemia and 3% chronic leukemia, with 75% of acute leukemias being of lymphoblastic origin. Over the past 50 years, survival rates have witnessed a remarkable increase, progressing from around 10% to achieving cure rates exceeding 90% in certain childhood ALL subgroups with the advent of combined therapies. Between 1999 and 2018, a total of 123 patients diagnosed with B-ALL were initially identified, but after applying exclusion criteria, 105 patients were included in the evaluation, who were treated with COG protocols at our center. The mean follow-up duration for patients was determined to be a median of 74 months (min to max: 2 to 228 months). When the cases were evaluated at the end of the study, 59 of 59 individuals in the standard risk group (100%), 21 of 26 individuals in the high-risk group (80.7%), and 14 of 20 individuals in the very high group (70%) were alive. Patients were categorized into 4 groups based on the methotrexate (MTX) doses they received during Phase 3 and Phase 5 of treatment. Event-free survival and overall survival were evaluated among these groups. It was observed that patients in the standard-risk group had significantly higher event-free and overall survival rates. However, no significant difference was found in survival rates when evaluated based on the treatment groups each risk group received by the patients.

Multiple Myeloma: Improved Outcomes Resulting from a Rapidly Expanding Number of Therapeutic Options

Multiple myeloma (MM) is a bone-marrow-based cancer of plasma cells. Over the last 2 decades, marked treatment advances have led to improvements in the overall survival (OS) of patients with this disease. Key developments include the use of chemotherapy, immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies. MM remains incurable, with outcomes influenced by many factors, including age, sex, genetics, and treatment response. This review summarizes recent studies regarding monitoring and treatment of MM, emphasizing the efficacy of new therapies, the impact of maintenance treatments, and approaches for managing relapsed or refractory MM. The role of specific drug classes used to treat MM, including immunomodulatory drugs, proteasome inhibitors, monoclonal antibodies, and newer treatments such as chimeric antigen receptor T-cell therapies and bispecific antibodies are discussed. Combination therapies have significantly improved outcomes. Maintenance therapies, particularly with lenalidomide, have been effective in extending OS but lead to an increased risk of secondary cancers. Venetoclax, selinexor, and ruxolitinib have shown potential as new therapeutic options for patients with relapsed or refractory MM. Immune-based treatments, such as chimeric antigen receptor T-cell therapy and bispecific antibodies, mark a major advancement for heavily pretreated patients, although challenges remain related to cost, availability, and side effects. The treatment landscape for patients with MM has seen significant progress, with current therapies providing a longer OS and better quality of life. Future research should focus on optimizing these strategies, personalizing therapies, and exploring new therapeutic targets.

Treatment of T-cell Leukemia/Lymphoma in Children and Young Adults With the Memorial Sloan Kettering Cancer Center New York IIB Protocol

We described the Memorial Sloan Kettering Cancer Center New York IIB (MSK-NYII) protocol pilot in 1993, for the treatment of acute lymphoblastic leukemia (ALL) in children at high risk of early relapse. We now report MSK-NYII for the treatment of T-ALL/T-lymphoma over a 15-year period. A review of all patient charts identified 63 treated from 1/1/2000-12/31/2015, with a median follow-up of 9.9 years. Further follow-ups were confounded by the COVID pandemic. Remissions (CR) were defined as <5% marrow blast count on Day 28 and resolution of extramedullary disease. Forty-four had T-ALL, and 19 had stage III/IV lymphoblastic lymphoma (T-LL). Median age at diagnosis was 13.6 years (range 0.4 to 23.7). At diagnosis central nervous system (CNS) leukemia was present in 7/63 patients (11%), cranial nerve palsy in 3 (5%), CNS2 [<5cells/µL cerebrospinal fluid with blasts seen on cytospin] in 11 (17%), testicular enlargement in 3 (5%), and mediastinal mass in 45 (71%). On Day 8, 37 T-ALL (86%) were rapid early responders with <25% marrow blasts. 54 patients had an examination, cerebrospinal fluid, and marrow evaluation on day 28. Remission was demonstrated in 53 (98%) after prior marrow and CNS disease. The 19 T-lymphoma patients had no evidence of disease on day 28. Four relapses in marrow were recorded during therapy. Second remissions were able to be achieved. One patient died without having relapsed and is counted as an event in the event-free survival (EFS) analysis. Four patients, including 3 after the second CR transplant, died during follow-up. One unusual case of T-ALL recurred as T-LL of the colon 5.5 years after diagnosis, 3.5 years after therapy discontinuation. Fifteen years after diagnosis 88% (95% CI=78%-98%) survived event-free, and 91% (95% CI=82%-100%) survived. Twenty-five patients received irradiation. Three had RT to the testes, 3 had cranial RT for cranial nerve palsies, and 19 had cranial radiation for either CNS leukemia, CNS2, or for initial white blood cell >100,000/ µL. The MSK-NYIIB protocol, with a 94% 5-year and 88% 15-year EFS, is an effective therapy for the treatment of T-ALL/lymphoma, with similar toxicity to other high-risk regimens.

Impact of Minimal Residual Diseases Status and Depth of Response on Survival Outcomes in Blinatumomab-Treated Acute Lymphoblastic Leukemia: A Systematic Review and Meta-Analysis

OBJECTIVES

Acute lymphoblastic leukemia (ALL) is a common hematological malignancy that occurs due to blockage of B-lymphocyte maturation at an early stage of development and differentiation. The Food and Drug Administration approved blinotumomab to manage relapsed/refractory ALL (R/R ALL). This review aimed to determine the comparative efficacy of blinatumomab in treating R/R ALL.

METHODS

Two reviewers searched 3 electronic databases, PubMed, ScienceDirect, and CENTRAL, for all relevant articles published until July 2024. All the articles that met the inclusion criteria were included in the review.

RESULTS

Four hundred thirty-seven articles were found from the electronic search; however, only 21 articles met the inclusion criteria. A pooled analysis of the outcomes found that blinatumomab resulted in an improvement in both the OS (HR: 0.65; 95% CI: 0.51, 0.82; P=0.0003) and the DFS (HR: 0.57; 95% CI: 0.41, 0.80; P=0.001). Further analysis showed that the CR rate and MRD response of ALL patients to blinatumomab was 51.6% (95% CI: 48.5%, 54.6%; P=0.319) and 64.6% (95% CI: 53.4%, 74.3%; P=0.011), respectively. The safety analysis indicated that the incidence of serious AEs was comparable in patients receiving blinotumomab and those receiving standard chemotherapy (OR: 1.34; 95% CI; 0.91, 1.97; P=0.14).

CONCLUSIONS

The findings show that blinatumomab is superior to standard chemotherapy in improving the OS and DFS of patients with R/R ALL. Furthermore, it has a more favorable safety profile, making it an effective alternative to conventional chemotherapy for managing R/R ALL.

Molecular Profiling Reveals Novel Gene Fusions and Genetic Markers for Refined Patient Stratification in Pediatric Acute Lymphoblastic Leukemia

Risk-adapted treatment protocols conferred remarkable improvement in the survival rates of pediatric acute lymphoblastic leukemia/lymphoma (ALL/LBL). Nevertheless, clinical management is still challenging in certain molecular subgroups and in the presence of alterations associated with an increased rate of relapse. In this study, disease-relevant genomic and transcriptomic profiles were established in a prospective, multicenter, real-world cohort involving 192 children diagnosed with ALL/LBL. Gene fusions were detected in 34.9% of B-ALL and 46.4% of T-ALL patients, with novel chimeric genes involving JAK2, KMT2A, PAX5, RUNX1, and NOTCH1, and with KMT2A-rearranged patients displaying the worst 3-year event-free survival (P = .019). Nonsynonymous mutations were uncovered in 74.9% of the analyzed patients, and pairwise scrutiny of genetic lesions revealed recurrent clonal selection mechanisms commonly converging on the same pathway (eg, Ras, JAK/STAT, and Notch) in individual patients. Investigation of matched diagnostic and relapse samples unraveled complex subclonal variegation, and mutations affecting the NT5C2, TP53, CDKN2A, and PIK3R1 genes, emerging at the time of relapse. TP53 and CREBBP mutations, even as subclonal aberrations, were associated with shorter 3-year event-free survival among all patients with B-ALL (TP53 mutant vs wild-type: P = .008, CREBBP mutant vs wild-type: P = .010), and notably, B-ALL patients showing no measurable residual disease on day 33 could be further stratified based on TP53 mutational status (P < .001). Our in-depth molecular characterization performed across all risk groups identified novel opportunities for molecularly targeted therapy in 55.9% of high-risk and 31.6% of standard/intermediate-risk patients.

Results of Cancer and Leukemia Group B 10102 (Alliance), a Phase 1/2 Study

BACKGROUND

Acute lymphoblastic leukemia (ALL) in adults is aggressive, with long-term outcomes impacted by treatment resistance and toxicity. CD52 is expressed in most cases of B- and T-lineage ALL. Alemtuzumab, a humanized immunoglobulin G1 monoclonal antibody that targets CD52, was identified as a potential agent to improve treatment efficacy without increasing toxicity.

METHODS

In this phase 1/2 study (Cancer and Leukemia Group B [CALGB] 10102, NCT00061945), a course of single-agent alemtuzumab was intercalated into CALGB 19802 backbone chemotherapy after the third course of intensive chemotherapy in those who were CD52+ at diagnosis. Phase 1 tested three dose levels of subcutaneous alemtuzumab (10, 20, and 30 mg 3 times weekly for 4 weeks/12 doses) and demonstrated that 30 mg was tolerable. Phase 2 established feasibility.

RESULTS

The study enrolled 295 evaluable patients (115 in phase 1, 180 in phase 2); 206 (69.8%) were CD52+. Among evaluable CD52+ patients, 43.7% (90/206) completed the first three treatment modules; 97.8% (88 of 90) were treated with alemtuzumab. Alemtuzumab was associated with cytomegalovirus viremia, which occurred in 23.3% (14 of 60) of patients during and 29.2% (19 of 65) after alemtuzumab treatment. With a median follow-up of 101.2 months, median overall survival (OS) was 26.3 months (3-year rate, 44%; 5-year rate, 36%; 10-year rate, 31%). Landmark analysis at the start of the fourth course of treatment demonstrated no difference in OS or disease-free survival between patients who did and who did not receive alemtuzumab.

CONCLUSION

Alemtuzumab was feasible to administer in adults with ALL receiving intensive chemotherapy, but was without evidence of benefit.

Prognostic relevance of treatment deviations in children with relapsed acute lymphoblastic leukemia who were treated in the ALL-REZ BFM 2002 study

Relapsed Acute Lymphoblastic Leukemia (ALL) is among the most common causes of cancer-associated deaths in children. However, little is known about the implications of deviations from ALL treatment protocols on survival rates. The present study elucidates the various characteristics of treatment deviations in children with relapsed ALL included in the ALL-REZ BFM 2002 (i.e., Relapse Berlin-Frankfurt- Münster) trial and determines their prognostic relevance for relapse and death rates. Among 687 patients, 100 were identified with treatment deviations, further classified, and examined by occurrence time, cause and type. Protocol deviation was considered a time-dependent variable and its impact on Disease Free Survival (DFS) and Overall Survival (OS) was examined using the time-dependent model Mantel Byar. Five years after the relapse diagnosis, deviations were significantly related to both inferior DFS (38%) and OS (57%) rates compared to protocol conformed treatment (DFS = 61%; OS = 70%, P < 0.001). Based on multivariate analyses, protocol deviation proved to be an independent adverse prognostic factor of DFS. Moreover, deviations triggered by chemotherapy-induced toxicity were associated with a higher relapse rate compared to deviations due to insufficient response. Therefore, to avoid impairment of results by deviations, future clinical trials, and treatment strategies should focus on less toxic treatments and stricter protocol compliance.

The evolution of nutritional care in children and young people with acute lymphoblastic leukaemia: a narrative review

BACKGROUND

Acute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy in the world. Advances in treatment protocols have resulted in survival rates of >80% in most high-income countries (HIC); however, children and young people (CYP) with ALL continue to face significant nutrition-related challenges during treatment.

METHODS

This narrative review outlines the changing landscape of treatment and survivorship for CYP with ALL and the advances in nutrition knowledge that call for changes to clinical nutrition practice.

RESULTS

The incidence of ALL has remained stable in HIC; however, there have been significant advances in survival over the past 30 years. Overweight and obesity are increasingly prevalent in CYP with ALL at diagnosis, during treatment and in survivorship. Coupled with poor diet quality, high-energy and saturated fat intakes, altered eating behaviours and inactivity, this necessitates the need for a shift in nutrition intervention. Undernutrition remains a concern for CYP with high-risk treatment protocols where oral or enteral nutrition support remains a cornerstone of maintaining nutrition status.

CONCLUSIONS

With improved treatment protocols and high survival rates, a shift to focusing on diet quality, prevention of excessive weight gain and obesity during treatment and survivorship is necessary.

Secondary neoplasms in survivors of pediatric acute lymphoblastic leukemia and lymphoblastic lymphoma: a single-center, retrospective study

Background

Acute lymphoblastic leukemia (ALL)-based therapeutic regimens have markedly improved the survival of children with ALL and lymphoblastic lymphoma (LBL). However, survivors are at risk of secondary neoplasms. Few studies on such secondary neoplasms have been conducted outside of Europe and the United States. The aim of this study was to evaluate the incidence of, risk factors for, and outcomes of secondary neoplasms in long-term survivors of ALL and LBL at a tertiary pediatric oncology center in Mie prefecture, Japan.

Procedure

We retrospectively reviewed 188 patients with ALL and LBL who were treated with an ALL-based therapeutic regimen at Mie University Hospital from January 1, 1977 to December 31, 2022 and followed up.

Results

Ten patients developed secondary neoplasms, with 10-year and 20-year cumulative incidences of 2.9% [standard error (SE) = 1.5%] and 5.5% (SE = 2.3%), respectively. The median interval between the primary-cancer diagnosis and secondary-neoplasm diagnosis was 18.5 years (range: 7.8-41.7 years). All 10 secondary neoplasms were central nervous system (CNS) tumors (6 meningiomas and 4 high-grade gliomas). Radiotherapy (p = 0.007) and CNS involvement in the primary cancer (p < 0.001) increased the risk of secondary neoplasms among long-term survivors. Gliomas occurred significantly earlier than meningiomas (p = 0.047), and three patients died of secondary neoplasms (all gliomas).

Conclusions

As secondary gliomas occurred earlier than meningiomas and are associated with poor outcomes, physicians should take great pains to minimize their risk to improve long-term survival and quality of life.

Characterization of CK2, MYC and ERG Expression in Biological Subgroups of Children with Acute Lymphoblastic Leukemia

Despite the excellent survival rate, relapse occurs in 20% of children with ALL. Deep analyses of cell signaling pathways allow us to identify new markers and/or targets promising more effective and less toxic therapy. We analyzed 61 diagnostic samples collected from 35 patients with B- and 26 with T-ALL, respectively. The expression of CK2, MYC and ERG genes using Sybr-Green assay and the comparative 2-ΔΔCt method using 20 healthy donors (HDs) was evaluated. We observed a statistically significant difference in CK2 expression in non-HR (p = 0.010) and in HR (p = 0.0003) T-ALL cases compared to HDs. T-ALL patients with PTEN-Exon7 mutation, IKZF1 and CDKN2A deletions showed high CK2 expression. MYC expression was higher in pediatric T-ALL patients than HDs (p = 0.019). Surprisingly, we found MYC expression to be higher in non-HR than in HR T-ALL patients. TLX3 (HOX11L2)-rearranged T-ALLs (27%) in association with CRLF2 overexpression (23%) showed very high MYC expression. In B-ALLs, we detected CK2 expression higher than HDs and MYC overexpression in HR compared to non-HR patients, particularly in MLL-rearranged B-ALLs. We observed a strong difference in ERG expression between pediatric T- and B-ALL cases. In conclusion, we confirmed CK2 as a prognostic marker and a therapeutic target.

Presence of minimal residual disease determined by next-generation sequencing is not a reliable prognostic biomarker in children with acute lymphoblastic leukemia

The role of next-generation sequencing (NGS) for minimal residual disease (MRD) assessment in pediatric acute lymphoblastic leukemia (ALL) is still under consideration. Fifty pediatric patients were prospectively evaluated for specific clonal rearrangements of immunoglobulin and T-cell receptor genes using NGS analysis at diagnosis and on days 33 and 78 from therapy onset. The prognostic value or the NGS-MRD status was analyzed after a median follow-up of 4 years. All but one patient with negative NGS-MRD status on day 33 are in clinical remission. A total of 29 (58%) patients were NGS-MRD positive on day 33, of which 9 (18%) patients remained positive on day 78. However, only a small percentage of the patients with positive NGS-MRD status on day 33 and day 78 relapsed: 21% (6/29) and 33% (3/9), respectively. Positive NGS-MRD status is not a reliable prognostic biomarker in children with ALL and warrants careful consideration in disease stratification.

Transcription factor KLF2 is associated with the dysfunctional status of NK cells and the prognosis of pediatric B-ALL patients

Background

Natural killer cells, an important component of the innate immune system, can directly recognize and lyse virally infected or transformed cells. However, NK cells fail to restrain the growth of malignancies, such as B-cell acute lymphoblastic leukemia (B-ALL). The molecular genetics of NK cells in the B-ALL bone marrow microenvironment and the mechanisms underlying the inhibited function of NK cells at the single-cell level remain largely elusive.

Methods

In this study, we studied the frequency and absolute number of NK cells in peripheral blood samples collected from 43 healthy volunteers and 104 pediatric B-ALL patients diagnosed at Hunan Children's Hospital. We also analyzed published single-cell RNA sequencing (scRNAseq) data from B-ALL and normal bone marrow samples using unsupervised clustering. Our findings were further validated using bulk transcriptomic data and clinical data from a cohort of 139 B-ALL bone marrow samples.

Results

We found that the frequency and number of NK cells were significantly decreased in the bone marrow and peripheral blood of B-ALL patients. In-depth analysis of scRNAseq data identified 12 NK cell clusters. Among them, the C2 cluster, which is present in healthy bone marrow but reduced in B-ALL bone marrow, displays overexpression of a transcription factor KLF2 and a significant downregulation of the "leukocyte proliferation" pathway. Furthermore, we found that the expression of KLF2 in B-ALL at diagnosis was positively correlated with the percentage of leukemia cells and the positive rate of minimal residual disease (MRD), indicating that KLF2 is a marker of poor prognosis.

Conclusion

There are dramatic differences at the single-cell level in the transcriptomics of NK cells between healthy donors and B-ALL patients. A transcription factor, KLF2, which is enriched in the C2 cluster of NK cells, has been suggested to regulate the proliferation of NK cells and is associated with poor prognosis of pediatric B-ALL.

Innovation in cancer pharmacotherapy through integrative consideration of germline and tumor genomes

Precision cancer medicine is widely established, and numerous molecularly targeted drugs for various tumor entities are approved or are in development. Personalized pharmacotherapy in oncology has so far been based primarily on tumor characteristics, for example, somatic mutations. However, the response to drug treatment also depends on pharmacological processes summarized under the term ADME (absorption, distribution, metabolism, and excretion). Variations in ADME genes have been the subject of intensive research for >5 decades, considering individual patients' genetic makeup, referred to as pharmacogenomics (PGx). The combined impact of a patient's tumor and germline genome is only partially understood and often not adequately considered in cancer therapy. This may be attributed, in part, to the lack of methods for combined analysis of both data layers. Optimized personalized cancer therapies should, therefore, aim to integrate molecular information, which derives from both the tumor and the germline genome, and taking into account existing PGx guidelines for drug therapy. Moreover, such strategies should provide the opportunity to consider genetic variants of previously unknown functional significance. Bioinformatic analysis methods and corresponding algorithms for data interpretation need to be developed to integrate PGx data in cancer therapy with a special meaning for interdisciplinary molecular tumor boards, in which cancer patients are discussed to provide evidence-based recommendations for clinical management based on individual tumor profiles. SIGNIFICANCE STATEMENT: The era of personalized oncology has seen the emergence of drugs tailored to genetic variants associated with cancer biology. However, the full potential of targeted therapy remains untapped owing to the predominant focus on acquired tumor-specific alterations. Optimized cancer care must integrate tumor and patient genomes, guided by pharmacogenomic principles. An essential prerequisite for realizing truly personalized drug treatment of cancer patients is the development of bioinformatic tools for comprehensive analysis of all data layers generated in modern precision oncology programs.

The Effect of Hematopoietic Stem Cell Transplantation on Treatment Outcome in Children with Acute Lymphoblastic Leukemia

PURPOSE

Hematopoietic stem cell transplantation (HSCT) has been an important method of treatment in the advance of pediatric acute lymphoblastic leukemia (ALL). The indications for HSCT are evolving and require updated establishment. In this study, we aimed to investigate the efficacy of HSCT on the treatment outcome of pediatric ALL, considering the indications for HSCT and subgroups.

MATERIALS AND METHODS

A retrospective analysis was conducted on ALL patients diagnosed and treated at a single center. Risk groups were categorized based on age at diagnosis, initial white blood cell count, disease lineage (B/T), and cytogenetic study results. Data on the patients' disease status at HSCT and indications of HSCT were collected. Indications for HSCT were categorized as upfront HSCT at 1st complete remission, relapse, and refractory disease.

RESULTS

Among the 549 screened patients, a total of 418 patients were included in the study; B-cell ALL (n=379) and T-cell ALL (T-ALL) (n=39). HSCT was conducted on a total of 106 patients (25.4%), with a higher frequency as upfront HSCT in higher-risk groups and specific cytogenetics. The overall survival (OS) was significantly better when done upfront than in relapsed or refractory state in T-ALL patients (p=0.002). The KMT2A-rearranged ALL patients showed superior event-free survival (p=0.002) and OS (p=0.022) when HSCT was done as upfront treatment.

CONCLUSION

HSCT had a substantial positive effect in a specific subset of pediatric ALL. In particular, frontline HSCT for T-ALL and KMT2A-rearranged ALL offered a better prognosis than when HSCT was conducted in a relapsed or refractory setting.

Impact of pre-infusion disease burden on outcomes in pediatric relapsed/refractory B-cell lymphoblastic leukemia following anti-CD19 CAR T-cell therapy

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapies have demonstrated high efficacy in pediatric patients with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Despite this success, the challenge of post-infusion relapse persists. In our study, we evaluate 116 children with R/R B-ALL who received anti-CD19 CAR T-cell therapy at our center. All patients were included in the response analysis and assessed for survival and toxicity. The CR rate was 98.3%, with 90.5% achieving minimal residual disease negative (MRD)- CR by day 28 (d28). The overall survival (OS) and event-free survival (EFS) were 69.3%±4.5% and 59.0%±4.6%, respectively, with a median follow-up duration of 47.9 months. The patients with pre-infusion MRD ≥ 1% was associated with lower 4-year OS (p = 0.006) and EFS (p = 0.027) comparing to those with MRD < 1%. The incidences of grade ≥ 3 cytokine release syndrome (CRS) and neurotoxicity were21.6 and 5.0%, respectively. Therefore, pre-infusion disease burden is a predictor of long-term outcome following anti-CD19 CAR T-cell therapy for pediatric R/R B-ALL.

Intestinal mucositis, systemic inflammation and bloodstream infections following high-dose methotrexate treatment in childhood acute lymphoblastic leukaemia: Comparison between the NOPHO ALL 2008 protocol and the ALLTogether1 protocol

Severe intestinal mucositis (IM) increases the risk of bloodstream infections (BSI) and inflammatory toxicity during acute lymphoblastic leukaemia (ALL) induction treatment. However, the implications of IM in subsequent ALL therapy phases after achieving remission remain unknown. This study investigated the relationship between IM (measured by plasma citrulline and the chemokine CCL20) and the development of BSI and systemic inflammation (reflected by C-reactive protein, CRP) in children with ALL during high-dose methotrexate (HDMTX) treatment, an important part of ALL consolidation therapy. The study compared patients treated according to the NOPHO ALL 2008 protocol (n = 52) and the ALLTogether1 protocol (n = 42), both with identical HDMTX procedures but different scheduling. One week post-HDMTX, citrulline dropped to median levels of 14.5 and 16.9 μM for patients treated according to the NOPHO ALL 2008 and ALLTogether1 protocols, respectively (p = 0.11). In a protocol and neutrophil count-adjusted analysis, hypocitrullinaemia (<10 μmol/L) was associated with increased odds of BSI within 3 weeks from HDMTX (OR = 26.2, p = 0.0074). Patients treated according to the NOPHO ALL 2008 protocol exhibited increased mucosal- and systemic inflammation post-HDMTX compared to patients treated according to ALLTogether1, with increased CCL20 (14.6 vs. 3.7 pg/mL, p < 0.0001) and CRP levels (10.0 vs. 1.0 mg/L, p < 0.0001). Both citrulline and CCL20 correlated with CRP for these patients (rs = -0.44, p = 0.0016 and rs = 0.35, p = 0.016, respectively). These results suggest that hypocitrullinaemia following HDMTX increases the risk of BSI, confirming previous observations from more intensive treatments. Moreover, these data indicate that the patients' vulnerability to mucositis and inflammatory toxicity after chemotherapy varies with treatment protocol.

ATP-Binding Cassette Transporter Genes and microRNAs in Pediatric B-Cell ALL: Expression Insights

BACKGROUND

Acute lymphocytic leukemia (ALL), characterized by uncontrolled growth of abnormal lymphocytes, predominantly affects children. Genetic analysis focusing on genes and microRNAs reveals important information about the biology of ALL, enabling accurate diagnosis and treatment. This study examines gene and microRNA expression in B cell ALL to improve early diagnosis and personalized treatment.

METHODS

Bone marrow samples were collected from patients both before and after the induction phase of chemotherapy. Comprehensive diagnostic techniques including flow cytometry, molecular assays, real-time PCR for common translocations, karyotyping, and complete blood count (CBC) analysis were employed. These methods were utilized to determine the type and risk assessment of ALL, identify specific gene and microRNA expressions, and measure blood cell counts.

RESULTS

The study comprised 12 patients, all under the age of 18. Post-treatment RT-PCR analysis revealed significant reductions in the expression of the ABCB1 gene, miR-129-5p, and miR-9-5p following the induction phase of chemotherapy. Karyotype analysis indicated that two patients were hypodiploid; unfortunately, both of these patients did not survive.

CONCLUSION

MicroRNAs and ABC genes serve as predictive and prognostic biomarkers in Acute Lymphoblastic Leukemia (ALL) and should be carefully reconsidered. It is more accurate to state that while microRNAs and ABC genes may potentially influence treatment response in ALL, further research is crucial to fully understand their roles in determining treatment outcomes.

Clinical Outcomes of Pediatric Acute Lymphoblastic Leukemia in the Bajio Region of Mexico: A Retrospective Cohort Study

Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood, and the Hispanic race has the highest incidence worldwide. Disparities in survival rates exist among different regions of the world. Due to this heterogeneity and possible differences in the outcomes within Mexico, the aim of this study was to analyze the clinical outcomes of cohort of pediatric patients with ALL treated in a highly specialized medical unit located in the Bajio region of Mexico. Observational retrospective study of a cohort of pediatric patients with ALL treated in a tertiary-level hospital in the Bajio region of Mexico, between January 2016 and December 2021. A total of 146 patients were included with a median age of 7 years. The 68.5% of patients were at high risk. CNS involvement was present in 2.7%, and Philadelphia chromosome positive in 2%. Cytogenetic analysis was performed in 16.4% patients. The median follow-up of entire cohort was 32 months. The most frequently administered chemotherapy treatment was Total Therapy XV in 79.5% of patients. The complete remission rate was 89%. Refractory disease was present in 2.7%. Induction-related mortality was 8.2%. The relapse rate was present in 26%. The 3-years overall survival was 57.5%, and the 3-years event-free survival was 53.4%. A more aggressive course and worse survival occur in our cohort of pediatric patients with ALL. Strategies should be proposed inside Mexico and other low-middle income countries with the aim of improving the overall survival.

Inhibiting H3K27 Demethylases Downregulates CREB-CREBBP, Overcoming Resistance in Relapsed Acute Lymphoblastic Leukemia

BACKGROUND

CREB binding protein (CREBBP) is a key epigenetic regulator, altered in a fifth of relapsed cases of acute lymphoblastic leukemia (ALL). Selectively targeting epigenetic signaling may be an effective novel therapeutic approach to overcome drug resistance. Anti-tumor effects have previously been demonstrated for GSK-J4, a selective H3K27 histone demethylase inhibitor, in several animal models of cancers.

METHODS

To characterize the effect of GSK-J4, drug response profiling, CRISPR-Dropout Screening, BH3 profiling and immunoblotting were carried out in ALL cell lines or patient derived samples.

RESULTS

Here we provide evidence that GSK-J4 downregulates cyclic AMP-responsive element-binding protein (CREB) and CREBBP in B-cell precursor-ALL cell lines and patient samples. High CREBBP expression in BCP-ALL cell lines correlated with high GSK-J4 sensitivity and low dexamethasone sensitivity. GSK-J4 treatment also induced Bcl-2 and Bcl-XL dependency and apoptosis.

CONCLUSIONS

This study proposes H3K27 demethylase inhibition as a potential treatment strategy for patients with treatment-resistant ALL, using CREBBP as a biomarker for drug response and combining GSK-J4 with venetoclax and navitoclax as synergistic partners.

Pediatric and adolescent cancer disparities in the Middle East and North Africa (MENA) region: incidence, mortality, and survival across socioeconomic strata

BACKGROUND

Cancer is one of the leading causes of death in children and adolescents, with a significant concentration in low and middle-income countries. Previous research has identified disparities in cancer incidence and mortality based on a country's level of development. The Middle East and North Africa (MENA) region comprises of countries with heterogeneous income and development levels. This study aims to investigate whether discrepancies in cancer incidence and mortality among children and adolescents exist in countries within the MENA region.

MATERIALS AND METHODS

Data on cancer incidence and mortality were drawn from the Global Burden of Disease Study (GBD) 2019 for all malignant neoplasms (including non-melanoma skin cancers). The analysis was restricted to children and adolescents aged less than 20 years. Mortality- to-Incidence ratios (MIR) were calculated as a proxy measure of survival for each cancer type and country and Spearman's correlation coefficient measured the association between socio-demographic index (SDI), incidence rates, mortality rates, and MIR.

RESULTS

In 2019, cancer incidence in the MENA region was 4.82/100,000 population, while mortality rate was 11.65/100,000 population. Cancer incidence and mortality was higher among males compared to females. A marked difference was observed in cancer-related mortality rates between low-income and high-income countries. MIR was higher in low-income countries, particularly for males and specific cancer types such as liver, colon and rectum, brain and central nervous system (CNS) cancers, and non-Hodgkin lymphoma among others. A negative correlation was observed between a country's SDI and MIR (-0.797) and SDI and mortality rates (-0.547) indicating that higher SDI corresponds to lower MIR and lower mortality rates.

CONCLUSION

These findings highlight the need for evidence-based interventions to reduce cancer-related mortality and disease burden among children and adolescents, particularly in low-income countries within the region and for cancer types with the highest mortality rates. Additionally, efforts should focus on establishing registries to provide up-to-date national data on cancer incidence and mortality in countries within the region.

Global, regional, and national burden of acute lymphoblastic leukemia in children: Epidemiological trends analysis from 1990 to 2021

Children are the main susceptible group to acute lymphoblastic leukemia (ALL), and the lack of sufficient data has impeded a comprehensive understanding of its global impact. This study analyzed the annual numbers and rates of incidence, deaths, and disability-adjusted life years (DALYs) of childhood ALL from 1990 to 2021, disaggregated by age group, gender, and socio-demographic index (SDI) at the global, regional, and national levels, based on the 2021 Global Burden of Disease (GBD) database. Although global deaths and DALYs rates for childhood ALL showed declining trends, the incidence rate fluctuated. Incidence rates in high SDI regions were higher, but deaths and DALY rates were lower. Moreover, the burden in Sub-Saharan Africa and other low SDI countries was growing. The burden on boys has been higher than on girls in this period. This study underscored improving prevention and treatment measures are critical to control the persistent global burden of children ALL.

The Proteomics of T-Cell and Early T-Cell Precursor (ETP) Acute Lymphocytic Leukemia: Prognostic Patterns in Adult and Pediatric-ETP ALL

BACKGROUND

The 5-year overall survival (OS) rates of T-cell lymphocytic leukemia (T-ALL) are better for children (>90%) compared to adults (~57%). The early T-cell precursor (ETP) T-ALL subtype is prognostically unfavorable in adults, but less significant in pediatric T-ALL, and the diagnosis and prognosis of "near"-ETP is controversial. We compared protein and RNA expression patterns in pediatric and adult T-ALL to identify prognostic subgroups, and to further characterize ETP and near-ETP T-ALL in both age groups.

METHODS

Protein expression was assessed using RPPA methodology for 321 target proteins in 361 T-ALL patient samples from 292 pediatrics and 69 adults, including 103 ETP-ALL. RNA-sequencing was performed on 81 pediatric T-ALL samples.

RESULTS

We identified recurrent protein expression patterns that classified patients into ten protein expression signatures using the "MetaGalaxy" analysis. In adults, Cox regression analysis identified two risk-groups associated with OS (p = 0.0002) and complete remission duration (p < 0.001). Cluster analysis of adults and pediatric-ETP patients identified three ETP-clusters strongly associated with age. Pediatric ETP-patients with a pediatric-dominant expression profile were associated with a shorter OS (p = 0.04) and event-free survival (p = 0.05) compared to pediatric ETP-patients with an ETP expression profile that was also identified in adults.

CONCLUSION

Our study demonstrates that proteomics are predictive of outcome in adult T-ALL and that we can identify a small subset of pediatric ETP with an inferior outcome. The observation that there are age-specific patterns supports the idea that the origin of T-ALL in most pediatric and adult patients is different, while overlapping patterns suggests that there are some with a common pathophysiology. Proteomics could enhance risk stratification in both pediatric and adults with T-ALL.

Deciphering the Therapeutic Potential of Novel Pentyloxyamide-Based Class I, IIb HDAC Inhibitors against Therapy-Resistant Leukemia

Histone deacetylase inhibitors (HDACi) are established anticancer drugs, especially in hematological cancers. This study aimed to design, synthesize, and evaluate a set of HDACi featuring a pentyloxyamide connecting unit linker region and substituted phenylthiazole cap groups. A structural optimization program yielded HDACi with nanomolar inhibitory activity against histone deacetylase class I/IIb enzymes. The novel inhibitors (4d and 4m) showed superior antileukemic activity compared to several approved HDACi. Furthermore, 4d and 4m displayed synergistic activity when combined with chemotherapeutics, decitabine, and clofarabine. In vitro pharmacokinetic studies showed the most promising profile for 4d with intermediate microsomal stability, excellent plasma stability, and concentration-independent plasma protein binding. Additionally, 4d demonstrated comparable in vivo pharmacokinetics to vorinostat. When administered in vivo, 4d effectively inhibited the proliferation of leukemia cells without causing toxicity. Furthermore, the binding modes of 4d and 4m to the catalytic domain 2 of HDAC6 from Danio rerio were determined by X-ray crystallography.

Association of B-Lineage Lymphoblastic Leukaemia Gene Polymorphisms with Poor Prognostic Features

OBJECTIVE

Of this study was to analyse the correlation of gene polymorphisms with clinical and laboratory data of paediatric patients with B-lineage acute lymphoblastic leukaemia with prognostically unfavourable features.

METHODS

A study of 200 children with B-lineage acute lymphoblastic leukaemia (B-ALL) treated with polychemotherapy programmes was conducted. Analysis by sex revealed a statistically insignificant predominance of the group of boys over girls (54%). The mean age of the subjects was 9.3±0.2 years. Genotyping of polymorphic loci was performed using TaqMan method of single site-specific amplification and genotyping. The data of patients with initial prognostically unfavourable clinical and laboratory data in the form of initial leukocytosis from 50 to 99 thousand - 10 (5%), over 100 thousand - 16 (8%), initial CNS lesion in the form of neuroleukaemia - 5 (2.5%), initial splenomegaly more than 6 cm - 12 (6%); patients with poor response to therapy, having absolute number of blast cells in peripheral blood over 1,000 on day 8 of treatment according to the protocol (response to prednisolone prophase) - 13 (7%), with unsatisfactory response to treatment on Day 15 - 40 patients (20%) and on Day 33 - 4 children (2%); also patients who developed relapse of the disease - 17 (9%).

RESULTS

According to the findings, of all 24 gene variants, 13 variants (54%), namely, HLA - rs6457327, TNF - rs1800630 and rs2229094, GATA3 - rs3824662, TP53 - rs1042522, CASP9 - rs4661636, CASP8 - rs10505477, CEBPE - rs2239633; PIP4K2A - rs7088318, CASC8 - rs10505477, IRF4 - rs87207, CYP1A1 - rs4646903 and rs7089424 of ARID5B gene were found to be associated with B-ALL and unfavourable prognostic features.

CONCLUSIONS

The findings of this study revealed significant associations of polymorphic genetic variants, which may serve as a basis for the development of effective methods for predicting the risk of relapse development and the timeliness of intensification of B-ALL treatment. Prompt genetic counselling of children with identified unfavourable genotypes of the investigated gene polymorphisms will make it possible to predict the development of relapse, resistance and/or poor response to B-ALL treatment, and to propose an individual strategy for monitoring children's health in the short and long term.

Characterisation of cells markers associated with IKZF1plus in BCP-ALL

The presence of IKZF1 deletions has been associated with an increased relapse rate in B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). There is a particular subset of IKZF1del cases called IKZF1plus (defined by the co-occurrence of IKZF1del and deletions in CDKN2A/B, PAX5, or the PAR1 region, in the absence of ERG deletions), which is also associated with worse prognosis, but some recent studies have not found major differences between the IKZF1del and IKZF1plus groups. Therefore, the IKZF1plus group still needs further comprehension and our study aims to characterise the molecular heterogeneity and identify molecular markers exclusively associated with IKZF1plus. Two independent series of cases (TARGET, n = 125 and GenLAb, n = 60) were evaluated by segregating patients into 3 groups: IKZF1plus, IKZF1del, and IKZF1wild. Differential expression analyses showed that the membrane protein-coding genes most associated with the IKZF1plus group were: KCNA5, GREB1, EPOR, SDK1, and PTPRB. Notably, KCNA5 and GREB1 differential expression levels were validated in the GenLAb validation series. Regarding copy number alterations, we observed a high frequency of VPREB1 deletions in the IKZF1plus group, as well as additional exclusive deletions in the CD200 and BTLA genes. Recent research suggests that the importance of the IKZF1plus profile varies depending on the genetic subgroup. In this scenario, we found associations between IKZF1plus and certain genes in BCP-ALL, being KCNA5 and GREB1 the most promising biomarkers for predicting IKZF1plus. A deeper understanding of these genetic profiles will allow a better risk assessment and offer precise rationale for therapeutic strategies in BCP-ALL.

Fear, coping and support- from the perspective of children aged 10-17-year old having acute lymphoblastic leukemia

PURPOSE

To describe experiences of fear, coping, and support in 10-17-year-old children under treatment for acute lymphoblastic leukaemia (ALL).

METHODS

A longitudinal descriptive qualitative design was adopted. Ten children participated in one to three interviews each (24 interviews in all). Interviews were analysed using a matrix-based qualitative method.

RESULTS

The variety of fears described related to uncertainty, pain and medical procedures, bodily changes and loss of control, complications, professionals' attitudes, affected school results, and social isolation. Children used various strategies to deal with fear: some more general, to cope with the whole situation, and others more related to specific events such as treatment and tests. The most reported strategies we labelled Accepting the situation, Positive thinking, and Being an active agent. Less favourable strategies were also reported. Health care professionals, families, and friends offered valuable, but different kinds of, support.

CONCLUSIONS

Children aged 10 to 17 undergoing treatment for ALL experience various fears. Each experience is individual and changes over time, but there are common patterns. Most children used problem-solving or emotional-regulation strategies, but withdrawal was also reported. Even children who can deal with fear need support from their health care professionals, families, and friends.

Late oral adverse effects of chemotherapy for hematological malignancies in children: A systematic review and meta-analysis of case-control studies

BACKGROUND

The purpose of the present systematic review and meta-analyses was to appraise the case-control studies that have evaluated late adverse effects of chemotherapy for treating hematological malignancies in pediatric patients.

METHODS

Five electronic databases along with grey literature were searched using broad keywords and MeSH terms for the articles that could meet the eligibility criteria. The Newcastle-Ottawa Scale was employed for quality assessment. DerSimonian and Laird random effects model using the (Restricted Maximum Likelihood) REML approach was used for meta-analyses to calculate the pooled Odds Ratios (ORs) for binary outcomes and Standardized Mean Difference (SMD) for continuous outcomes. The GRADE approach was used to synthesize the certainty of evidence utilizing GRADEpro® GDT software.

RESULTS

8,052 records were obtained from the searches. After duplicate removal and initial screening of titles and abstracts, 109 articles were subjected to full-text reading but only 5 could be included. The pooled ORs of having root malformation, microdontia, tooth agenesis, taurodontism, and enamel defects in patients who have undergone treatment were 7.68, 5.39, 3.74, 2.00, and 1.84 compared to controls, respectively. The SMD for dental caries was also significant among the groups (p= 0.03) and indicated an SMD of 0.27 (95% CI: 0.03, 0.51) indicating higher pooled mean DMFT in the cases than controls.

CONCLUSIONS

Root malformations are associated with treatment for childhood hematological cancers with a moderate certainty of assessment. Tooth agenesis and microdontia are associated with low certainty of evidence, while taurodontism, enamel defects, and caries were associated with very low certainty of evidence. Future studies on larger sample sizes are needed to validate the findings as the number of studies included in our review was small.

Digital PCR-based quantification of miR-181a in the cerebrospinal fluid aids patient stratification in pediatric acute lymphoblastic leukemia

Despite remarkable improvements in the survival of pediatric acute lymphoblastic leukemia (ALL), sensitive detection and clinical management of central nervous system leukemia (CNSL) are still immensely challenging. Blast cells residing in the CNS but not circulating in the cerebrospinal fluid (CSF) remain undetected by current diagnostic methods, preventing a truly risk-adapted anti-leukemic treatment in this compartment. We examined the clinical applicability of the molecular marker microRNA (miR)-181a quantified in the cell-free CSF to evaluate the level of CNS involvement and to optimize patient stratification based on CNS status. Normalized copy number of miR-181a was longitudinally profiled using droplet digital PCR, and the results were compared with the degree of leukemic involvement of the CNS. After combining cytospin- and flow cytometry (FCM) data with miR-181a expression, we could stratify previously ambiguous cases and reclassify patients into a CNS-positive/miR-significant group (mean ± SE for miR-181a copies: 3300.70 ± 809.69) bearing remarkable infiltration as well as into CNS-minimal/miR-significant and CNS-minimal/miR-minimal groups differentiating putative, clinically significant occult CNSL cases (2503.50 ± 275.89 and 744.02 ± 86.81 copies, respectively, p = 1.13 × 10-6). In summary, miR-181a expression is a promising biomarker for CNSL detection, facilitating the robust identification of patients who could benefit from intensified CNS-directed therapy.

Targeting splicing for hematological malignancies therapy

Alterations in splicing patterns of leukemic cells have a functional impact and influence most cellular processes since aberrantly spliced isoforms can provide a proliferative advantage, enable to evade apoptosis, induce metabolic reprogramming, change cell signaling and antitumor immune response, or develop drug resistance. In this Review, we first characterize the general mechanism of mRNA processing regulation with a focus on the role of splicing factors, which are commonly mutated in blood neoplasms. Next, we provide a comprehensive summary on the current understanding of alternative splicing events, which confer resistance to targeted treatment strategies and immunotherapy. We introduce the functional consequences of mis-spliced variants (CD19-∆ex2, CD22-∆ex2, CD22-∆ex5-6, CD33-∆ex2, PIK3CD-S, BCR-ABL35INS, BIM-γ, FPGS-8PR, dCK-∆ex2-3, and SLC29A1-∆ex13) production in leukemic cells. Of therapeutic relevance, we summarize novel strategies focused on pharmacological correction of aberrant splicing, including small-molecule splicing modulators and splice-switching oligonucleotides. We also include the findings of recent preclinical investigation of the antisense strategies based on modified oligonucleotides. Finally, we discuss the potential of emerging combination therapies for the treatment of hematological disorders with disrupted splicing.

NG2 is a target gene of MLL-AF4 and underlies glucocorticoid resistance in MLLr B-ALL by regulating NR3C1 expression

ABSTRACT

B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer, with long-term overall survival rates of ∼85%. However, B-ALL harboring rearrangements of the MLL gene (also known as KMT2A), referred to as MLLr B-ALL, is common in infants and is associated with poor 5-year survival, relapses, and refractoriness to glucocorticoids (GCs). GCs are an essential part of the treatment backbone for B-ALL, and GC resistance is a major clinical predictor of poor outcome. Elucidating the mechanisms of GC resistance in MLLr B-ALL is, therefore, critical to guide therapeutic strategies that deepen the response after induction therapy. Neuron-glial antigen-2 (NG2) expression is a hallmark of MLLr B-ALL and is minimally expressed in healthy hematopoietic cells. We recently reported that NG2 expression is associated with poor prognosis in MLLr B-ALL. Despite its contribution to MLLr B-ALL pathogenesis, the role of NG2 in MLLr-mediated leukemogenesis/chemoresistance remains elusive. Here, we show that NG2 is an epigenetically regulated direct target gene of the leukemic MLL-ALF transcription elongation factor 4 (AF4) fusion protein. NG2 negatively regulates the expression of the GC receptor nuclear receptor subfamily 3 group C member 1 (NR3C1) and confers GC resistance to MLLr B-ALL cells. Mechanistically, NG2 interacts with FLT3 to render ligand-independent activation of FLT3 signaling (a hallmark of MLLr B-ALL) and downregulation of NR3C1 via activating protein-1 (AP-1)-mediated transrepression. Collectively, our study elucidates the role of NG2 in GC resistance in MLLr B-ALL through FLT3/AP-1-mediated downregulation of NR3C1, providing novel therapeutic avenues for MLLr B-ALL.

The third generation AKR1C3-activated prodrug, ACHM-025, eradicates disease in preclinical models of aggressive T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy that expresses high levels of the enzyme aldo-keto reductase family 1 member C3 (AKR1C3). To exploit this finding, we developed a novel prodrug, ACHM-025, which is selectively activated by AKR1C3 to a nitrogen mustard DNA alkylating agent. We show that ACHM-025 has potent in vivo efficacy against T-ALL patient-derived xenografts (PDXs) and eradicated the disease in 7 PDXs. ACHM-025 was significantly more effective than cyclophosphamide both as a single agent and when used in combination with cytarabine/6-mercaptopurine. Notably, ACHM-025 in combination with nelarabine was curative when used to treat a chemoresistant T-ALL PDX in vivo. The in vivo efficacy of ACHM-025 directly correlated with AKR1C3 expression levels, providing a predictive biomarker for response. Together, our work provides strong preclinical evidence highlighting the potential of ACHM-025 as a targeted and effective therapy for aggressive forms of T-ALL.

Results of the prospective EORTC Children Leukemia Group study 58081 in precursor B- and T-cell acute lymphoblastic leukemia

Here, we report the results of the prospective cohort study EORTC-CLG 58081 and compare them to the control arm of the randomized phase 3 trial EORTC-CLG 58951, on which treatment recommendations were built. In both studies, patients aged 1-18 years with BCR::ABL1 negative acute lymphoblastic leukemia of the B-lineage (B-ALL) or T-lineage (T-ALL) were treated using a BFM backbone without cranial irradiation. Similarly to the control arm of 58951, prednisolone (PRED) 60 mg/m2/day was used for induction therapy, but a few modifications were made. Dexamethasone (DXM) was used in average-risk 2 (AR2) T-ALL and B-ALL during induction, 10 and 6 mg/m2/day, respectively. Leucovorin rescue was delayed to 42 h instead of 36 h after initiation of high-dose methotrexate, and a postconsolidation MRD time point was added to stratify patients. Between 2011 and 2017, 835 patients were prospectively enrolled in the 58081 study. Overall, the 5-year event-free survival (EFS) was 84.8% versus 83.6% (hazard ratio [HR], 0.96 [95% confidence interval [CI]: 0.76-1.21]) for 58081 versus 58951 considered as a control group, respectively, 84.3% versus 84.9% (HR, 1.06 [99% CI: 0.75-1.49]) in B-ALL but 87.3% versus 76.6% (HR, 0.59 [99% CI: 0.28-1.24]) in T-ALL. The comparison between the two studies regarding EFS differed by risk group (p = 0.012). The HR was 2.15 (99% CI: 0.67-6.85) for very low-risk but 0.34 (99% CI: 0.13-0.89) for AR2. The particularly favorable results observed in the T-ALLs and AR2 subgroups suggest the benefit of using DXM in specific patient groups and highlight the importance of risk stratification.

Asciminib stands out as the superior tyrosine kinase inhibitor to combine with anti-CD20 monoclonal antibodies for the treatment of CD20+ Philadelphia-positive B-cell precursor acute lymphoblastic leukemia in preclinical models

Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (Ph+ BCP-ALL) is a high-risk subtype of acute lymphoblastic leukemia characterized by the presence of the BCR::ABL1 fusion gene. Tyrosine kinase inhibitors (TKI) combined with chemotherapy are established as the first-line treatment. Additionally, rituximab, an anti-CD20 monoclonal antibody is administered to adult BCP-ALL patients with ≥20% CD20+ blasts. In this study, we observed a marked prevalence of CD20 expression in patients diagnosed with Ph+ BCP-ALL, indicating a potential widespread clinical application of rituximab in combination with TKI. Consequently, we examined the influence of TKI on the antitumor effectiveness of anti-CD20 monoclonal antibodies by evaluating levels of CD20 on the cell surface and conducting in vitro functional assays. All tested TKI were found to uniformly downregulate CD20 on leukemic cells, diminishing the efficacy of rituximab-mediated complement- dependent cytotoxicity. Interestingly, these TKI displayed varied effects on natural killer (NK) cell-mediated antibody- dependent cytotoxicity and macrophage phagocytic function. While asciminib demonstrated no inhibition of effector cell functions, dasatinib notably suppressed the anti-CD20-monoclonal antibody-mediated NK cell cytotoxicity and macrophage phagocytosis of BCP-ALL cells. Dasatinib and ponatinib also decreased NK cell degranulation in vitro. Importantly, oral administration of dasatinib, but not asciminib, compromised NK cell activity in patients' blood, as determined by an ex vivo degranulation assay. Our results indicate that asciminib might be preferred over other TKI for combination therapy with anti-CD20 monoclonal antibodies.

Efficacy and Safety Profile of Biosimilar Polyethylene Glycol (PEG)-Asparaginase (Asviia) in Patients With Acute Leukemia: A Retrospective Study From Kashmir

BACKGROUND

 Biosimilar pegylated L-asparaginase offers a promising alternative to the innovator molecule for treating acute lymphoblastic leukemia (ALL) in Indian children. It addresses challenges associated with drug availability and cost while providing similar therapeutic advantages. This biosimilar ensures wider access to essential treatment in resource-limited settings such as India.

MATERIALS AND METHODS

 A retrospective study was conducted at the Pediatric Oncology unit of the Department of Medical Oncology, Sher-I-Kashmir Institute of Medical Sciences (SKIMS) Srinagar. The study evaluated the efficacy and safety of biosimilar polyethylene glycol-asparaginase (PEG-ASP) (Asviia) in newly diagnosed pediatric ALL patients treated between January 2021 and December 2023. Each patient received two induction doses of PEG-ASP.

RESULTS

 The study included 45 patients (29 boys, 16 girls) with a median age of 7.5 years (range: 1-16 years), with most patients diagnosed with Pre-B ALL. The median PEG-ASP dose administered intravenously was 1175 IU (range: 1125-3750 IU). Significant improvements in hemoglobin and platelet counts were observed following the first dose of PEG-ASP. The biosimilar PEG-ASP was well tolerated, with no life-threatening events reported. At the end of the induction phase, 40 patients (88.89%) achieved complete remission with minimal residual disease (MRD) negativity, while five patients had MRD positivity.

CONCLUSION

 The study provides valuable insights into the efficacy and safety of biosimilar PEG-ASP for pediatric ALL in resource-limited settings, with strong data on remission rates and minimal adverse events.

Temporal changes in survival among adult patients with acute lymphoblastic leukaemia diagnosed in the period 1998-2020 - A Danish nationwide population-based cohort study

BACKGROUND

Previous studies have shown continuous improved overall survival (OS) up to 2015 for young adults with acute lymphoblastic leukaemia (ALL). However, recently several important advances have been made justifying a more contemporary analysis of outcomes in adult with ALL.

METHODS

In this nationwide population-based cohort study, we included patients above 18 years of age diagnosed with ALL between January 1, 1998, and December 31, 2020. Patients were followed until December 31, 2022. By employing flexible parametric survival models, we quantified progress in OS using the key endpoint of 2-year age standardized OS for all patients and clinical subgroups of interest.

FINDINGS

This study includes 657 patients and demonstrates a significant improvement in OS over time with the 2-year age standardized OS increasing from 36·4 % (95 % CI, 27·0-45·8 %) for patients diagnosed in 1998 to 68·6 % (95 % CI, 60·2-76·9)for patients diagnosed in 2020, corresponding to an absolute increase in 2-year OS of 32·2 % points (95 % CI, 19·1-45·2). Stratified analysis revealed improvements for both Philadelphia chromosome positive and negative ALL, across cytogenetic risk groups, and for B- and T-cell ALL, whereas the latter did not reach statistical significance. Improvements were seen across all ages; however, most pronounced for Philadelphia chromosome positive ALL and patients below 60 years of age.

INTERPRETATION

These results show a universal and continuous improvement in the treatment of adult ALL. Currently, novel treatment combination and advances in cellular therapy occur rapidly, and we expect even further improvements in the years to come.

FUNDING

Northern Region of Denmark.

Precision Medicine for Acute Lymphoblastic Leukemia in Children: A Review

The clinical outcome for children diagnosed with acute lymphoblastic leukemia is a testimony to the success of modern medicine. Over the past few decades, survival has climbed from ∼10% to >90% for certain subgroups. Yet, the outcome for those with relapsed disease is often poor, and survivors struggle with a multitude of healthcare issues, some of which are lifelong. In recent years, the advent of the widespread sequencing of tumors has made available patients with previously unrecognized subtypes of leukemia, who have the potential to benefit from the addition of targeted therapies. Indeed, the promise of precision medicine, encompassing a person's environment, genetics and lifestyle, is likely to have profound impact on further tailoring therapies that are likely to improve outcomes, diminish toxicity and ultimately pave the pathway for a healthier population.

Impact of Age on Pharmacogenomics and Treatment Outcomes of B-Cell Acute Lymphoblastic Leukemia

PURPOSE

Acute lymphoblastic leukemia (ALL) can occur across all age groups, with a strikingly higher cure rate in children compared with adults. However, the pharmacological basis of age-related differences in ALL treatment response remains unclear.

METHODS

Studying 767 children and 309 adults with newly diagnosed B-cell ALL enrolled on frontline trials at St Jude Children's Research Hospital, MD Anderson Cancer Center, the Alliance for Clinical Trials in Oncology, and the ECOG-ACRIN Cancer Research Group, we determined the ex vivo sensitivity of leukemia cells to 21 drugs. Twenty-three ALL molecular subtypes were identified using RNA sequencing. We systematically characterized the associations between drug response and ALL genomics in children, adolescents and young adults, and elderly adults. We evaluated the effect of age-related gene expression signature on ALL treatment outcomes.

RESULTS

Seven ALL drugs (asparaginase, prednisolone, mercaptopurine, dasatinib, nelarabine, daunorubicin, and inotuzumab ozogamicin) showed differential activity between children and adults, of which six were explained by age-related differences in leukemia molecular subtypes. Adolescents and young adults showed similar patterns of drug resistance as older adults, relative to young children. Mercaptopurine exhibited subtype-independent greater sensitivity in children. Transcriptomic profiling uncovered subclusters within CRLF2-, DUX4-, and KMT2A-rearranged ALL that were linked to age and cytotoxic drug resistance. In particular, a subset of children had adult-like ALL on the basis of leukemia gene expression patterns across subtypes, despite their chronological age. Resistant to cytotoxic drugs, children with adult-like ALL exhibited poor prognosis in pediatric ALL trials, even after adjusting for age and minimal residual diseases.

CONCLUSION

Our results provide pharmacogenomic insights into age-related disparities in ALL cure rates and identify leukemia prognostic features for treatment individualization across age groups.

Low-risk relapsed acute lymphoblastic leukemia in children and young adults: what have we learnt and what's next?

While outcomes for newly diagnosed children with acute lymphoblastic leukemia (ALL) have improved over the last few decades, 10-15% will relapse. Outcomes for those children with relapse remains a challenge, with 5-year overall survival of approximately 35-60%. Large cooperative group trials have identified factors associated with favorable (low risk, LR) outcome at relapse, including later relapse, B-cell phenotype, isolated extramedullary relapse and a good response to initial re-induction therapy. Contemporary therapeutic regimens are aimed at improving outcomes, while decreasing toxicity. A main focus of current research involves how immunotherapy can be best incorporated with cytotoxic chemotherapy to improve survival in relapsed ALL. Here we review therapeutic strategies for LR relapse, including review of recently completed and ongoing trials.

Benzene exposure and pediatric leukemia: From molecular clues to epidemiological insights

According to the International Agency for Research on Cancer, leukemia ranks 14th in incidence and 11th in mortality and has a 5-year prevalence of approximately 1300,000 cases. Acute lymphoblastic leukemia is the most common hematopoietic syndrome in children during the first 5 years of life and represents approximately 75 % of all neoplasms among the pediatric population. The development of leukemia is strongly governed by DNA alterations that accelerate the growth of bone marrow cells. Currently, the most examined factor in pediatric leukemia is exposure to multiple compounds, such as hydrocarbons. Benzene, an aromatic hydrocarbon, can cause health challenges and is categorized as a carcinogen. Benzene toxicity has been widely associated with occupational exposure. Importantly, studies are underway to generate evidence that can provide clues regarding the risk of environmental benzene exposure and hematological problems in children. In this review, we summarize the existing evidence regarding the effects of benzene on pediatric leukemia, the associations between the effect of benzene on carcinogenesis, and the presence of certain molecular signatures in benzene-associated pediatric leukemia. Although there is sufficient evidence regarding the effects of benzene on carcinogenesis and leukemia, epidemiological research has primarily focused on occupational risk. Moreover, most benzene-induced molecular and cytogenetic alterations have been widely described in adults but not in the pediatric population. Thus, epidemiological efforts are crucial in the pediatric population in terms of epidemiological, clinical, and biomedical research.