Pediatric Acute Lymphoblastic Leukemia Cases Research Articles

Philadelphia chromosome-like acute lymphoblastic leukemia with concomitant rearrangements of CRLF2 and ABL1: a pediatric case report

BackgroundBCR::ABL1-like or Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) was first reported in 2009. Ph-like ALL is characterized by gene signature similar to Philadelphia chromosome ALL, but without BCR::ABL1 fusions. Molecularly, Ph-like ALL is divided into seven categories, with CRLF2 and ABL-class rearrangements being the two most common subtypes, exhibiting alterations in distinct downstream signaling cascades.Case presentationWe report a rare case of pediatric Ph-like ALL with concomitant CRLF2 and ABL1 rearrangements. CRLF2 was fused with P2RY8, its most common fusion partner, whereas ABL1 was fused with MYO18B, a novel fusion partner that has not been previously reported. The 4-year-old female patient was treated using the national multicenter CCCG-ALL-2020 protocol with the addition of dasatinib at the end of induction when ABL1 rearrangement was confirmed by RNA-seq. Morphologically and molecularly, the patient remained in continuous remission until the last follow-up. To the best of our knowledge, this is the first case of Ph-like ALL harboring two distinct rearrangement categories.ConclusionsOur results identified that ABL1 rearrangement and CRLF2 rearrangement can coexist. The application of FISH, whole transcription sequencing, PCR can help us to have a more comprehensive understanding of ALL cytogenetics and molecular biology. Further studies are needed to explore the role of targeted therapies in such rare clinical scenarios.

Unraveling Copy Number Alterations in Pediatric B-Cell Acute Lymphoblastic Leukemia: Correlation with Induction Phase Remission Using MLPA.

Acute Lymphoblastic Leukemia (ALL) is the most common malignancy occurring in children. Copy number alterations (CNA) like PAX5, CDKN2A/2B, PAR1 Region, ETV6, IKZF1, BTG1, and RB1 gene deletion are important genetic events that define and prognosticate B-cell ALL. Thus, this study aimed to evaluate associations of CNA with induction phase remission status in childhood B-cell ALL. This study was observational with a cross-sectional design at the Dharmais Cancer Hospital, Harapan Kita Mother and Children Hospital, and Tangerang Regional Public Hospital. We evaluated 74 pediatric B-cell ALL cases with 1-18-year-olds. Genomic DNA was analyzed by Multiplex Ligation Dependent Probe Amplification Assay (MLPA). This study used the P335 ALL-IKZF1 panel kit, which contains several ALL-related genes. The patient's clinical and laboratory characteristics were collected from medical records from January to December 2019. We observed gene copy number alteration in children with B-Cell ALL. PAX5 was the most commonly observed gene deletion, followed by CDKN21/2B, ETV6, IKZF1, BTG1, RB1, and PAR1 Region. Based on gene mutations, only the PAX5 had a significant association with the remission status of pediatric B-cell ALL (p-value <0.05; OR = 3.91). It showed that patients with PAX5 gene mutations have 3.9 times the risk of no remission and/or relapse compared to those without PAX5 gene mutations. Patients with mutations in the PAX5 gene have a higher chance of not achieving remission and/or experiencing relapse than those without such mutations. The MLPA method can be utilized for examining copy number alterations, which is valuable for achieving more precise stratification in diagnosis.. Further research is needed to expand upon this finding.

Waning of Humoral Immunity to Vaccine-Preventable Diseases in Children Treated for Acute Lymphoblastic Leukemia: A Single-Center Retrospective Cross-Sectional Analysis

The survival rates of children with acute lymphoblastic leukemia (ALL) have improved over the years, but infections remain a significant cause of morbidity and mortality. Chemotherapy has a range of harmful side effects including the loss of protective antibodies against vaccine-preventable diseases. The objective of this study was to evaluate the serological status of pediatric ALL cases before and after intensive chemotherapy. Children treated and followed for ALL at Dokuz Eylül University were included in this retrospective cross-sectional study. Antibody levels against hepatitis A, hepatitis B, and rubella were routinely assessed at both the time of diagnosis and 6 months after completion of chemotherapy. Measles, mumps, and varicella antibody levels were evaluated at only 6 months after treatment. Seventy-eight children who completed chemotherapy for ALL were enrolled in the study. All participants had non-protective antibody levels for at least one of the diseases. The highest seropositivity rate was found for hepatitis A (55.1%) and the lowest for measles (17.9%) after chemotherapy. Overall, 50.7%, 30.6%, and 45.7% of the patients significantly lost their humoral immunity against hepatitis B, hepatitis A, and rubella, respectively. Patients in the higher-risk group for ALL had lower seropositivity rates than patients of the other risk groups. There were statistically significant relationships between the protective antibody rates for hepatitis A and varicella and the ages of the patients. Except for hepatitis A vaccination, pre-chemotherapy vaccination did not affect post-chemotherapy serology. On the other hand, all children with a history of varicella before diagnosis showed immunity after chemotherapy. Patients with ALL, including those previously fully vaccinated, are at great risk of infection due to the decrease in protective antibody levels after chemotherapy. There is a need for routine post-chemotherapy serological testing and re-vaccination based on the results obtained.

Abstract B110: Race/ethnicity, socioeconomic status, and early death among children enrolled in clinical trials for acute lymphoblastic leukemia

Abstract Introduction: Prior work indicates that Hispanic and Black children diagnosed with leukemia may experience a higher risk of death in the period shortly after diagnosis, but no work has examined these disparities taking into account leukemia subtypes and the role socioeconomic status (SES) may play. We investigated reported race/ethnicity (RRE), health insurance status, neighborhood SES, and early death among pediatric acute lymphoblastic leukemia (ALL) patients enrolled on clinical trials. Methods: Using data from the Childhood Cancer Research Network as well as Children’s Oncology Group therapeutic trials, we estimated the associations between RRE (Non-Hispanic [NH] White, NH Black, NH Asian/Pacific Islander [PI], or Hispanic/Native American), health insurance status, neighborhood SES using the Yost Index, and death within 60 days of diagnosis using multivariable logistic regression. All analyses were adjusted for age at diagnosis, sex, and ALL subtype (Standard Risk B-Cell, High Risk B-Cell, Infant ALL, T-Cell). We also estimated associations among non-infant patients diagnosed with B-Cell ALL, additionally adjusting for standard or high-risk disease. All associations were estimated as odds ratios (OR) with 95% confidence intervals (CI). Results: Overall, we analyzed data from 8,634 pediatric ALL cases (7,559 B-Cell; 122 Infant ALL; 953 T-Cell) enrolled across 7 clinical trials (AALL0232, AALL0331, AALL0434, AALL0631, AALL0932, AALL1131, AALL1231). In total, there were 29 deaths within 60 days of diagnosis, including 22 among B-Cell, 4 among infant ALL, and 3 among T-Cell patients. In the full analysis, infant ALL subtype was very strongly associated with early death compared to Standard Risk B-Cell patients (OR: 37.8 [95% CI: 9.22, 137]). We also observed a suggestive association between NH Asian/PI RRE and higher odds of early death compared to NH Whites (OR: 3.10 [95% CI: 0.71, 9.63]), which remained after limiting the analysis to B-Cell patients (OR: 5.63 [95% CI: 1.24, 18.7]). No association was apparent between NH Black or Hispanic/Native American RRE and odds of early death. Neighborhood SES was not significantly associated with early death, though point estimates suggested a potential protective effect of increasing SES. Lack of health insurance was also suggestively associated with greater odds of early death (OR: 2.78 [95% CI: 0.60, 9.47]). Conclusion: Unlike prior work, we observed increased odds of death soon after diagnosis for NH Asian/PI children. Future work incorporating more detailed treatment and cytogenetic subtype information is needed to identify the factors contributing to this disparity. Citation Format: Sarah Lucht, Jeannette M. Sample, Logan Spector, Jenny N. Poynter, Lucie Turcotte, Erin L. Marcotte. Race/ethnicity, socioeconomic status, and early death among children enrolled in clinical trials for acute lymphoblastic leukemia [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B110.

Somatic and Germline Cohesin Genes Alterations in Pediatric Acute Lymphoblastic Leukemia

Leukemia is a complex disease and the molecular mechanisms of malignant transformation are not fully understood yet. Cohesins are essential proteins, forming a complex which plays critical roles in various cellular processes, not only by canonical DNA binding and chromosome segregation but also in non-canonical regulation of gene expression in both proliferating and post-mitotic cells. Mutations or gene expression alterations of genes encoding the components of the cohesins' complex may affect chromosomal stability and potentially contribute to the pathogenesis of leukemia. Somatic cohesins mutations have been already reported to occur in myeloproliferative disorders and pediatric Acute Lymphoblastic Leukemia (ALL), while on the other hand, germline mutations are causative of Cohesinopathies such as Cornelia de Lange Syndrome (CdLS). Our previous first report of a patient affected by both CdLS and ALL suggested a potential involvement of cohesin germline mutations in the pathogenesis of ALL. Moreover, we demonstrated that germline mutations in STAG1 gene could play a crucial role in predisposition to pediatric hematological malignancies, including ALL. These findings suggest that both somatic and germline alterations of cohesin genes may be associated with the development of ALL. This study aims to understand the molecular mechanisms affected by Cohesin genes alterations, that could potentially pave the way for the development of targeted therapies and improved treatment strategies for leukemia patients. By employing a DNA-targeted next-generation sequencing (NGS) screening of a cohort of 120 consecutive pediatric ALL cases (enrolled in the AIEOP-BFM protocol at various Italian centers), we discovered a total of 11 germline cohesin mutations, further categorized as follows: 6 out of 11 were missense, 4 out of 11 were located in the 3' or 5' untranslated regions (UTR) and 1 out of 11 was a splice-acceptor variant. To investigate the functional implications of selected germline mutations in STAG1 gene, we took advantage of the CRISPR/Cas9 technique to generate in vitro models of two Lymphoblastoid Cell Lines (LCLs) harboring specific variants already found in two patients of our cohort. Additionally, we established control LCLs from healthy donors' samples using the same CRISPR/Cas9 approach. Subsequently, we performed RNA sequencing (RNAseq) analysis on these cell lines, and our preliminary findings revealed a total of 619 differentially expressed genes (DEGs) compared to the control group. Many of them are involved in critical intracellular pathways, like ribosomal transcription, suggesting potential disruptions of essential cellular processes caused by germline STAG1 mutations. Moreover, we have successfully developed an advanced computational analysis pipeline with the primary objective of detecting fusion transcripts from RNAseq data. This pipeline was applied to a dataset of 529 consecutive diagnose and 95 relapse samples of pediatric B/T-ALL patients and in five B-ALL cases a fusion transcript involving the STAG1 (n=1), STAG2 (n=3), and NIPBL (n=1) genes was identified. The significance of these findings was further reinforced by additional cases from both pediatric and adult cohorts through an international collaborative effort and five more fusion transcripts of STAG2 (n=2) and NIPBL (n=3) were uncovered. Investigation to clarify the underlying functional consequences of these fusion genes in pediatric ALL are ongoing. Collectively, these observations endeavor to elucidate the role of germline and somatic cohesin events in pediatric ALL. In particular, the investigation seeks to unveil the non-canonical functions of these proteins, thus paving the way for the identification and characterization of a novel and distinct subcategory of leukemia within the pediatric population.

Relapsed/Refractory T- Acute Lymphoblastic Leukemia - Current Options and Future Directions.

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. The T-cell subtype (T-ALL) accounts for 10-15% of pediatric ALL cases and has been historically associated with outcomes inferior to those of B-cell ALL (B-ALL). The prognosis of T-ALL has significantly improved with contemporary intensive pediatric regimens. However, most children with relapsed T-ALL have dismal outcomes and fewer therapeutic salvage options than those available for B-ALL. After demonstrating efficacy in relapsed T-ALL, nelarabine is being increasingly incorporated into frontline T-ALL regimens. The development of genomic sequencing has led to the identification of new T-ALL subgroups and potential targeted therapeutic approaches which could improve patients' outcomes and reduce the toxicity associated with current therapy. Immunotherapy and cellular therapy regimens are also under early investigation in T-cell malignancies. This review outlines the clinical and biological characteristics of T-ALL and provides an overview of novel treatment options for refractory and relapsed T-ALL.

Periconceptional folate intake influences DNA methylation at birth based on dietary source in an analysis of pediatric acute lymphoblastic leukemia cases and controls

Periconceptional folate intake is associated with the establishment of DNA methylation in offspring; however, variations in this relation by food sources compared with folic acid supplements are not described. Also, maternal folate intake is associated with decreased risk of pediatric acute lymphoblastic leukemia (ALL), but the mechanism is not known. We evaluated the relation between periconceptional folate intake by source and DNA methylation at birth in a cohort of pediatric ALL cases and controls in an epigenome-wide association study. Genome-wide DNA methylation status obtained from archived neonatal blood spots from pediatric ALL cases (n=189) and controls (n=205) in the California Childhood Leukemia Study (CCLS) from 1995-2008 was compared with periconceptional folate from total, food, and supplemental sources using multivariable linear regression. Further stratification was performed by income, education, ethnicity, and total folate intake. We evaluated variable DNA methylation response to periconceptional folate by ALL case status through an interaction term. Two significant differentially methylated probes (DMPs) were associated with food and supplemental periconceptional folate intake in all subjects (n=394). The top differentially methylated region at the promoter region of DUSP22(dual specificity phosphatase 22) demonstrated DNA hypermethylation in ALL cases but not in controls in response to total and food folate intake. We further identified 8 interaction term DMPs with variable DNA methylation response to folate intake by ALL case status. Further stratification of the cohort by education and ethnicity revealed a substantially higher number of DMPs associated with supplemental folic acid intake in Hispanic subjects with lower income and educational level. We identified modest associations between periconceptional folate intake and DNA methylation differing by source, including variation by ALL case status. Hispanic subjects of lower income and education appear uniquely responsive to periconceptional folate supplementation.

Clinical Features and Risk Factors of Severe Pneumonia in Children With Acute Lymphoblastic Leukemia.

ObjectiveThis study aims to analyze the clinical characteristics of pediatric acute lymphoblastic leukemia (ALL) complicated by pneumonia and the risk factors of severe cases to preliminarily construct a prediction model for ALL complicated by severe pneumonia.MethodsA retrospective analysis was carried out on the clinical data of children diagnosed with ALL complicated by pneumonia hospitalized at the Department of Pediatrics of the Affiliated Hospital of Southwest Medical University between January 2013 and December 2020. The risk factors of severe ALL complicated by pneumonia were investigated with logistic regression analysis, and the risk prediction model was constructed.ResultsA total of 116 cases of pediatric ALL complicated by pneumonia were analyzed. There were 71 cases of mild pneumonia and 45 cases of severe pneumonia. The main clinical manifestations were cough in 112 cases and fever in 109. Pathogens were detected in 23 cases. Multiple regression factor analysis indicated that the use of hormones (OR 4.001, 95% CI: 1.505–10.632), neutropenia or agranulocytosis (OR 7.472, 95% CI: 2.710–20.602), hemoglobin (Hb) < 90 g/L (OR 3.270, 95% CI: 1.256~8.516), and C-reactive protein (CRP) >15 mg/L (OR 3.253, 95% CI: 1.209~8.751) were independent risk factors that were associated with severe pneumonia. Logistic regression was used to establish the risk prediction model of ALL with severe pneumonia. The p-value was 0.659. The area under the receiver operating characteristic curve was 0.851, and the sensitivity and specificity were 84.4 and 71.8%, respectively.ConclusionThe development of severe pneumonia may be affected by the use of hormones, neutropenia or agranulocytosis, Hb < 90 g/L, and CRP > 15 mg/L. The prediction model based on the risk factors is effective, which can provide a reference for the clinical evaluation of acute lymphoblastic leukemia with severe pneumonia.

Evaluating Methotrexate Toxicity and Its Association with ABCB1 Genetic Polymorphism in Children with Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is among the most prevalent type of hematologic malignancy in children. The Children’s Oncology Group protocol recognizes methotrexate (MTX) as a therapy for this problem in children, despite its several complications. The relationship between MTX toxicity and ATP-binding cassette subfamily B member 1 (ABCB1) SNPs in ALL children patients has been investigated in many studies. Objectives: Regarding the controversial findings reported by these studies, the present work aims to evaluate Methotrexate toxicity and its association with ABCB1 Genetic Polymorphism in ALL pediatric patients. Methods: Blood samples were collected from pediatric ALL patients. Next, DNA was extracted and polymerase chain reaction (PCR) was conducted using 300 μMol/μL of direct primers in 50 µL as the ultimate volume. ABCB1 gene was amplified using the PCR technique, and 0.5% agarose gel electrophoresis was used to identify reaction products. Afterward, the PCR fragments’ length was proved by observing through UV-transilluminator. Finally, liver and blood toxicity was studied in all cases under treatment with MTX. Results: In the present study, 81 children with ALL (36 females and 45 males) with a mean age of 6.32 ± 3.08 years old were examined. The ABCB1 1199 G-&gt;A gene mutation frequency and the ABCB1 3435 C-&gt;T gene mutation frequency was 4.9 and 70.4%, respectively. The results showed no statistically significant difference between leukopenia, gastrointestinal toxicity, renal toxicity, hepatotoxicity, anemia, thrombocytopenia, and neutropenia in cases having homozygous heterozygous ABCB1 3435 C-&gt;T and ABCB1 1199 G-&gt;A mutant polymorphisms than those having ordinary polymorphism. Conclusions: Overall, it seems that C3435 T, G1199A, and ABCB1 are not significant MTX toxicity markers in pediatric ALL cases.

Cryptic TCF3 fusions in childhood leukemia: Detection by RNA sequencing.

Acute lymphoblastic leukemia (ALL) is the most frequent malignancy in childhood and adolescence. In more than 60% of cases of this heterogeneous disease, a genetic marker is identified via cytogenetic or molecular analyses. TCF3 gene fusions occur in 5%-11% of ALL patients. In < 1%, the TCF3 alteration in ALL leads to a TCF3-HLF fusion gene. Even though this is a very rare event, the detection of a TCF3-HLF fusion gene is associated with a very poor prognosis with incurable relapses in almost all patients. The frequent TCF3-PBX1 fusion gene, which is detectable in 5%-10% of childhood B-cell precursor ALLs and ~3.8% of adult B-cell precursor ALLs, is associated with a rather good prognosis, that is, an observed event-free 5-year survival of approximately 85%. Thus, the distinction of the different partner genes fused to TCF3 is essential for risk assessment. To verify RNA sequencing as a tool for detection of known and unknown fusion genes, we screened 200 cases of pediatric B-cell precursor ALL with "targeted" RNA sequencing in a pilot project in comparison to classical cytogenetic analyses (chromosome R-banding analysis), fluorescence in situ hybridization, and PCR. We observed a TCF3 fusion gene in 6.5% (13/200) of the patients. Ten (5%) patients displayed a TCF3-PBX1 fusion gene, two (1%) patients a TCF3-FLI1 fusion gene, and one (0.5%) patient a TCF3-HLF fusion gene. For the TCF3 fusions, we obtained discrepant results with the different methods, which are described in the article. Taken together, translocations leading to TCF3 fusion genes might appear cryptic and may remain undetected by a single method.

MYBL2 Gene Polymorphism Is Associated With Acute Lymphoblastic Leukemia Susceptibility in Children.

PurposeAlthough MYBL2 had been validated to participate in multiple cancers including leukemia, the role of MYBL2 polymorphisms in acute lymphoblastic leukemia (ALL) was still not clear. In this study, we aimed to evaluate the association between MYBL2 single nucleotide polymorphisms (SNPs) and ALL risk in children.MethodsA total of 687 pediatric ALL cases and 971 cancer-free controls from two hospitals in South China were recruited. A case-control study by genotyping three SNPs in the MYBL2 gene (rs285162 C>T, rs285207 A>C, and rs2070235 A>G) was conducted. The associations were assessed by odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Subgroup and stratification analyses were conducted to explore the association of rs285207 with ALL risk in terms of age, sex, immunophenotype, risk level, and other clinical characteristics. The false-positive report probability (FPRP) analysis was performed to verify each significant finding. Functional analysis in silico was used to evaluate the probability that rs285207 might influence the regulation of MYBL2.ResultsOur study demonstrated that rs285207 was related to a decreased ALL risk (adjusted OR = 0.78; 95% CI = 0.63-0.97, P = 0.022) in the dominant model. The associations of rs285207 with ALL risk appeared stronger in patients with pre B ALL (adjusted OR=0.56; 95% CI=0.38-0.84, P=0.004), with normal diploid (adjusted OR=0.73; 95% CI=0.57-0.95, P=0.017), with low risk (adjusted OR=0.68; 95% CI=0.49-0.94, P=0.021), with lower WBC (adjusted OR=0.62; 95% CI=0.43-0.87, P=0.007) or lower platelet level (adjusted OR=0.76; 95% CI=0.59-0.96, P=0.023). With FPRP analysis, the significant association between the rs285207 polymorphism and decreased ALL risk was still noteworthy (FPRP=0.128). Functional analysis showed that IKZF1 bound to DNA motif overlapping rs285207 and had a higher preference for the risk allele A. As for rs285162 C>T and rs2070235 A>G, no significant was found between them and ALL risk.ConclusionIn this study, we revealed that rs285207 polymorphism decreased the ALL risk in children, and rs285207 might alter the binding to IKZF1, which indicated that the MYBL2 gene polymorphism might be a potential biomarker of childhood ALL.

Severe Hypercalcemia as Rare Manifestation of Acute Lymphoblastic Leukemia in Adolescent

Background: Hypercalcemia is a rare manifestation of acute lymphoblastic leukemia (ALL). Several studies reported that severe hypercalcemia is very uncommon in pediatric ALL, but there is no report regarding ALL in adolescence and young adult (AYA) which comprises distinct entity with diverse prognosis. Clinical Case: A 18-year-old male presented with prolonged fever, general weakness, fatigue, pale and decrease of body weight for 3 months. He also complained visual disturbances which progressively worsened for 1 month. On admission, systemic examination showed that he was alert, had tachycardia, proptosis of both eyes and splenomegaly. There was neither lymphadenopathy nor thyroid/parathyroid abnormality. Initial laboratory investigation revealed pancytopenia (hemoglobin of 6.8 g/dl, hematocrit of 19.1%, white blood cell count of 3.8 x 109/L with platelets of 58 x 109/L and no blast). There was severe hypercalcemia of 18 mg/dL, hypomagnesemia 1.14 mg/dL, with normal phosphorus level. His serum creatinine level slightly increased to 1.3 mg/dL with filtration rate of 79 ml/min/1.73 m2. Bone marrow evaluation showed blast cells infiltration, consistent with ALL type L3. Leukemia phenotyping revealed B cell-lineage with aberrant exp CD5. CT scan orbita and brain showed bilateral retrobulbar mass and diffuse lytic lesion in skeletal bones due to leukemic cells infiltration. Patient was treated with supplemental oxygen, hydration targeting natriuresis, loop diuretic and steroid. The serum calcium level remained high, thus bisphosphonate was given. There was progressive decline of serum calcium level after therapy. The patient is then prepared to start chemotherapy. Discussion: Hypercalcemia is associated with both PTH or PTH-independent mechanism, including malignancy. It complicates 5–20% of malignancy, but only 0.6–4.8% reported in leukemia. Hypercalcemia in malignancy may present due to: (1) direct invasion of cancer cells to bone and (2) secretion of humoral PTH-related peptide (PTHrP) which mimics PTH. Severe hypercalcemia without inadequate treatment is fatal. Initial treatment of hypercalcemia includes hydration, loop diuretic, calcitonin and bisphosphonate targeting decline of serum calcium level of 3–9 mg/dL in 24–48 hours. The main treatment of leukemia-related hypercalcemia is chemotherapy. Several cases of pediatric ALL reported normocalcemia after starting induction phase of chemotherapy and exerted good prognosis. Conclusion: Hypercalcemia should be investigated in leukemia patients and vice versa. The main aim of therapy is to normalize the serum calcium level and treat underlying causes. In adolescent ALL, adequate treatment of hypercalcemia helps achieving better outcome.

Rare and favorable prognosis of pediatric acute lymphoblastic leukemia with TLS-ERG fusion gene: Case report with long-term follow-up and review of literature

In the study of acute myeloid leukemia (AML), TLS-ERG (also called FUS-ERG or TLS/FUS-ERG) was found to be closely associated with extramedullary disease (EMD), with very poor prognosis. However, the occurrence of TLS-ERG in acute lymphoblastic leukemia (ALL) is very rare. Till date, only 20 cases of ALL with TLS-ERG gene have been reported, of which six are children. Therefore, many clinical aspects of ALL with TLS-ERG gene remain unknown. The aim of this study was to report the clinical features and outcomes of four TLS-ERG-positive pediatric ALL cases. The results showed that all four pediatric patients with this fusion gene achieved an excellent outcome even with a very short-term induction chemotherapy of less than two months. These findings indicated that children with TLS-ERG-positive ALL have very low risk of leukemia, and can be treated and cured with less intensive chemotherapy.

Droplet Digital PCR Improves IG-/TR-based MRD Risk Definition in Childhood B-cell Precursor Acute Lymphoblastic Leukemia.

Minimal residual disease (MRD) is the most powerful prognostic factor in pediatric acute lymphoblastic leukemia (ALL). Real-time quantitative polymerase chain reaction (RQ-PCR) represents the gold standard for molecular MRD assessment and risk-based stratification of front-line treatment. In the protocols of the Italian Association of Pediatric Hematology and Oncology (AIEOP) and the Berlin-Frankfurth-Munschen (BFM) group AIEOP-BFM ALL2009 and ALL2017, B-lineage ALL patients with high RQ-PCR-MRD at day+33 and positive at day+78 are defined slow early responders (SERs). Based on results of the AIEOP-BFM ALL2000 study, these patients are treated as high-risk also when positive MRD signal at day +78 is below the lower limit of quantification of RQ-PCR (“positive not-quantifiable,” POS-NQ). To assess whether droplet digital polymerase chain reaction (ddPCR) could improve patients’ risk definition, we analyzed MRD in 209 pediatric B-lineage ALL cases classified by RQ-PCR as POS-NQ and/or negative (NEG) at days +33 and/or +78 in the AIEOP-BFM ALL2000 trial. ddPCR MRD analysis was performed on 45 samples collected at day +78 from SER patients, who had RQ-PCR MRD ≥ 5.0 × 10–4 at day+33 and POS-NQ at day+78 and were treated as medium risk (MR). The analysis identified 13 of 45 positive quantifiable cases. Most relapses occurred in this patients’ subgroup, while ddPCR NEG or ddPCR-POS-NQ patients had a significantly better outcome (P < 0.001). Overall, in 112 MR cases and 52 standard-risk patients, MRD negativity and POS-NQ were confirmed by the ddPCR analysis except for a minority of cases, for whom no differences in outcome were registered. These data indicate that ddPCR is more accurate than RQ-PCR in the measurement of MRD, particularly in late follow-up time points, and may thus allow improving patients’ stratification in ALL protocols.

Observed reduction in the diagnosis of acute lymphoblastic leukaemia in children during the COVID-19 pandemic.

To contain the spread of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), the Norwegian government implemented lock-down restrictions from 13.03.2020: schools, day cares and after-school activities were closed, 2-week quarantine was required following international travel, physical distancing (2 metres) was recommended and groups were restricted to 5 people.

“SOCIOECONOMIC FACTORS AFFECTING SURVIVAL IN CHILDREN WITH ACUTE LYMPHOBLASTIC LEUKEMIA FROM NORTH-EAST INDIA”

Acute lymphoblastic leukemia (ALL) is a highly curable childhood cancer with a survival rate of nearly 80% in developed countries but is around 45% in developing countries. This retrospective study analyzed the association between demographic and socioeconomic factors with survival in pediatric ALL. All confirmed cases of pediatric ALL (age &lt;18 years) registered at Dr. B Borooah Cancer Institute between 2010 to 2017 were analyzed using data collected from hospital-based cancer registry and case records. Seventy-five confirmed cases of pediatrics ALL were eligible for the study. The median age of presentation was six years with a male: female ratio 1.9:1. Overall survival at 4-years was 43.8%, with a median survival of 25 months. A trend for higher 4-year overall survival was seen in female children (54.1% versus 37.9%, p=0.097). Patients from rural areas (44% versus 39.5%, p=0.308), with higher maternal education (83.3% versus 41.1%, p=0.161) and patients who did not abandon treatment (49.1% versus 31.2%, p=0.497) had better survival, but the differences were not significant. Four years overall survival in upper-middle, lower-middle, upper-lower, and lower class were 85.7%, 74.9%, 38.1%, and 7.7% respectively (upper-middleversus lower socioeconomic class, p=0.0001).Multivariate analyses confirmed a statistically significant relationship between socioeconomic status and survival, with the upper-middle group had a 90% decreased risk of death compared to the lower socioeconomic group. There is an urgent need for a proper definition of the problems of childhood ALL to introduce appropriate policies for improving survival in developing countries.

The intriguing occurrence of Acute Myeloid Leukemia in a case of Acute Lymphoblastic leukemia:Report of two cases

The aim of this study is to study the two cases of acute lymphoblastic leukemia (ALL) who relapsed as acute myeloid leukemia (AML). Presented here are reports of two cases of pediatric ALL who developed change of lineage to AML at relapse. This change in phenotype, which involves the conversion of one phenotype to other phenotype during the course of disease or at relapse is a rare phenomenon rarely described in literature. The immunophenotypic and molecular findings are described. The present study emphasizes the need of immunophenotyping and molecular workup at relapse. Also adds to the repertoire of the published literature on this rare entity.

Effective targeting of NAMPT in patient-derived xenograft models of high-risk pediatric acute lymphoblastic leukemia.

The prognosis for children diagnosed with high-risk acute lymphoblastic leukemia (ALL) remains suboptimal, and more potent and less toxic treatments are urgently needed. We investigated the efficacy of a novel nicotinamide phosphoribosyltransferase inhibitor, OT-82, against a panel of patient-derived xenografts (PDXs) established from high-risk and poor outcome pediatric ALL cases. OT-82 was well-tolerated and demonstrated impressive single agent in vivo efficacy, achieving significant leukemia growth delay in 95% (20/21) and disease regression in 86% (18/21) of PDXs. In addition, OT-82 enhanced the efficacy of the established drugs cytarabine and dasatinib and, as a single agent, showed similar efficacy as an induction-type regimen combining three drugs used to treat pediatric ALL. OT-82 exerted its antileukemic action by depleting NAD+ and ATP, inhibiting the NAD+-requiring DNA damage repair enzyme PARP-1, increasing mitochondrial ROS levels and inducing DNA damage, culminating in apoptosis induction. OT-82 sensitivity was associated with the occurrence of mutations in major DNA damage response genes, while OT-82 resistance was characterized by high expression levels of CD38. In conclusion, our study provides evidence that OT-82, as a single agent, and in combination with established drugs, is a promising new therapeutic strategy for a broad spectrum of high-risk pediatric ALL for which improved therapies are urgently needed.

Novel GTF2I\u2013PDGFRB and IKZF1\u2013TYW1 fusions in pediatric leukemia with normal karyotype

BackgroundMany cases of acute lymphoblastic leukemia (ALL) carry visible acquired chromosomal changes of pathogenetic, diagnostic, and prognostic importance. Nevertheless, from one-fourth to half of newly diagnosed ALL patients have no visible chromosomal changes detectable by G-banding analysis at diagnosis. The introduction of powerful molecular methodologies has shown that many karyotypically normal ALLs carry clinically important submicroscopic aberrations.Case presentationWe used fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH), RNA sequencing, reverse transcription (RT) and genomic polymerase chain reaction (PCR), as well as Sanger sequencing to investigate a case of pediatric ALL with a normal karyotype. FISH with a commercial PDGFRB breakapart probe showed loss of the distal part of the probe suggesting a breakpoint within the PDGFRB locus. aCGH revealed submicroscopic deletions in chromosome bands 5q32q35.3 (about 30 Mb long, starting within PDGFRB and finishing in the CANX locus), 7q34 (within TCRB), 9p13 (PAX5), 10q26.13 (DMBT1), 14q11.2 (TRAC), and 14q32.33 (within the IGH locus). RNA sequencing detected an in-frame GTF2I–PDGFRB and an out-of-frame IKZF1–TYW1 fusion transcript. Both fusion transcripts were verified by RT-PCR together with Sanger sequencing and interphase FISH. The GTF2I–PDGFRB fusion was also verified by genomic PCR and FISH. The corresponding GTF2I–PDGFRB fusion protein would consist of almost the entire GTF2I and that part of PDGFRB which harbors the catalytic domain of the tyrosine kinase. It would therefore seem to lead to abnormal tyrosine kinase activity in a manner similar to what has been seen for other PDGFRB fusion proteins.ConclusionsThe examined pediatric leukemia is a Ph-like ALL which carries novel GTF2I–PDGFRB and IKZF1–TYW1 fusion genes together with additional submicroscopic deletions. Because hematologic neoplasms with PDGFRB-fusion genes can be treated with tyrosine kinase inhibitors, the detection of such novel fusions may be clinically important. Since the GTF2I–PDGFRB could be detected only after molecular studies of the leukemic cells, further investigations of ALL-cases, perhaps especially but not exclusively with a normal karyotype, are needed in order to determine the frequency of GTF2I–PDGFRB in leukemia, and also to find out which clinical impact the fusion may have.

Analysis of Genetic Abnormalities in Newly Diagnosed Acute Lymphoblastic Leukemia Patients at King Faisal Specialist Hospital & Research Centre

Background/Purpose: Acute lymphoblastic leukemia (ALL) is a heterogeneous hematological neoplasm arising from B and T lymphocyte precursors with diverse genetic alterations. Identifying genetic abnormalities is essential for classification, risk stratification, minimal residual disease monitoring and targeted therapy administration. This extensive study provides details of ALL genetic aberrations in our community and compares these findings with international reference data.Methodology: Analysis for bone marrow aspiration of 568 newly diagnosed ALL patients at King Faisal Specialist Hospital and Research Centre (KFSH&RC) between 2012 and 2016 was carried out through karyotyping and a specific fluorescence in situ hybridization (FISH) panel. Depending on the type and age of newly diagnosed ALL patient, the specific FISH ALL panel was selected out of three ALL panels including; pediatric or adult panels for B-cell ALL or T-cell ALL panel. However, an adolescent age-group (15-19 years) is separated as individual entity. This lead results in a better understanding and concordance with different conflicted epidemiological studies in which a childhood ALL case might be considered with (0-14 years) or (0-19 years). Finally, the collected results were also paralleled to the reference data acquiring from the current World Health Organization (WHO) classification for hematological and lymphoid neoplasms, 2008, and its update 2016.Results: The median diagnosis age was 8 years (range 0.08-89 years) with a male to female ratio 1.5:1 in 568 newly diagnosed ALL patients. There were 118 (21%) cases referred from outside hospital to be diagnosed or in the process of transferring the patient. Cytogenetic and FISH abnormalities were evident in 431 samples (76%) of all cases. B-ALL and T-ALL constituted 489 (86%) and 79 (14%) of all cases. The pediatric ALL cases, excluding the adolescent group, represented 402 (71%) of all cases, of which B-ALL being the clear majority by 360 cases (90%). Cases in age between 15 and 19 years of age were account for only 56 cases (10%) of all cases. The adult-group consisted of 110 patients (19%) of ALL cases with B and T-ALL representing 77% and 23%, respectively (table 1). In the B-ALL group, Philadelphia-positive t(9;21) ALL, KMT2A (MLL) rearrangement, t(12;21) ETV6/RUNX1 translocation, hyperdiploidy, hypodiploidy, t(1;19), intrachromosomal amplification (iamp) 21 and complex groups were detected by classical cytogenetic, FISH or both in 8% (3% in pediatric-ALL, 7% in adolescent-ALL and 31% in adult-ALL), 4% (5%, 2% & 2%), 11% (15%, 0% & 0%), 40% (49%, 19% & 13%), 3% (3%, 7% & 0%), 2% (1%, 9% & 5%), 4% (5%, 5% & 0%) and 4% (3%, 7% & 6%), respectively (table 2). Investigation of genetic abnormalities among newly diagnosed T-ALL revealed only 46 positive cases (58%) with two third of these cases (31 cases) harboring a deletion of chromosome 9 short arm.Conclusion: These enormous data supported the value of applying different diagnostic methods to detect genetic alterations among newly diagnosed ALL patients. In addition, our ALL population show a different pattern of genetic abnormality rates which is evident by a higher rate of hyperdiploidy and lower high risk genetics frequencies. These could have an impact on the relapse and overall survival. Further regional collaborative study between multicenter and correlation with the clinical outcomes are demanded to strengthen these observations and might have a positive effect on our ALL patients. DisclosuresNo relevant conflicts of interest to declare.