Recent advances in the management of pediatric acute lymphoblastic leukemia

Sequelae and post-thrombotic syndrome after venous thromboembolism in acute lymphoblastic leukemia survivors treated on the NOPHO ALL2008 protocol

The treatment of acute lymphoblastic leukemia (ALL) is frequently complicated by toxicity, including venous thromboembolism (VTE) affecting roughly 8% of patients. VTE can lead to post-thrombotic syndrome (PTS), a group of signs and symptoms developed as a complication to deep venous thrombosis (DVT), imposing risk of permanent disability and reduced quality of life (QoL). PTS prevalence ranges from 0% to 70%, reflecting very heterogenous cohorts and assessment tools. We aimed to estimate sequelae, including PTS and QoL in children and adults (<45 years old) who had a DVT during ALL treatment. PTS and QoL scores were obtained through use of Villalta and Modified Villalta Scale, PedsQL, and Short Form-36 questionnaires. The cohort comprised 20 children (<18 years) and seven adults (median age: 12.9 years, range: 2-44 years) at the time of DVT diagnosis. In total, 25 ALL survivors underwent PTS examination. The examination took place when survivors were 7-48 years (median age: 20.3 years, median follow-up time 6.8 years). QoL was assessed correlating cases with three matching ALL survivors without VTE. Two adults (15.4%) showed mild or moderate PTS. Eight children (66.7%) were diagnosed with mild PTS, while three cases had collaterals as sole symptoms. Pain or symptoms affecting daily life were reported by 16%. No difference in QoL was found (p = .9). This study underscores the need for comprehensive population-based investigations with validation of PTS instruments in ALL survivors.

Cyclin D2 gene variance and expression level in pediatric acute lymphoblastic leukemia

BACKGROUND

Cyclin D2 (CCND2) is a crucial player in cell cycle regulation. CCND2 polymorphisms contribute to cancer predisposition.

OBJECTIVES

To evaluate the association of CCND2 rs3217927 single nucleotide polymorphisms (SNP) and its expression levels with acute lymphoblastic leukemia (ALL) susceptibility in Egyptian children and its potential prognostic role.

METHODS

The 5' nuclease allelic discrimination assay was used to evaluate the frequency of CCND2 rs3217927 SNP in 80 newly diagnosed children with ALL and 80 age- and sex-matched controls. CCND2 relative expression levels were determined by real-time quantitative polymerase chain reaction.

RESULTS

The genotype analysis revealed that the GG genotype and G allele were significantly more prevalent among ALL patients than controls (p ˂ .001). Regression analysis demonstrated that Egyptian children carrying only one G allele had about 31-fold increased risk to develop ALL compared to A allele carriers. CCND2 was overexpressed in ALL patients compared to controls (p < .001). The CCND2 overexpression was associated with the GG genotype and G allele (p < .001). Furthermore, G allele was an independent negative prognostic marker for central nervous system (CNS) involvement (odds ratio [OR] = 4.676; 95% confidence interval [CI]: 1.2-18.6), risk stratification (OR = 38; 95% CI: 7.7-188.2), and chemoresistance (OR = 9.864; 95% CI: 5.6-70.3) in ALL patients.

CONCLUSIONS

G allele of CCND2 rs3217927 SNP might be associated with increased risk for ALL in Egyptian children besides being an independent negative prognostic marker for their risk stratification and therapeutic outcome. CCND2 rs3217927 SNP genotyping might be used to demarcate ALL patients with aggressive disease phenotypes who may be candidate for alternative targeted therapeutic strategies.

Disparities in economic burden for children with leukemia insured by resident basic medical insurance: evidence from real-world data 2015–2019 in Guangdong, China

Background

Pediatric leukemia is the most prevalent childhood cancer in China and incurs heavy economic burden to patients without sufficient insurance protection. Although all Chinese children are obliged to enroll in the national insurance scheme, “Resident Basic Medical Insurance (RBMI)”, the protection may vary among patient subgroups. This study is designed to measure the disparities in economic burden for patients with leukemia under RBMI protection and explore the influencing factors.

Methods

The included patients were aged ≤ 15 and diagnosed with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML, with/without transplantation). They all completed treatment course consecutively in Nanfang Hospital and Zhujiang Hospital from Jan.1, 2015, to Dec.30, 2019, in Guangzhou, China. Their inpatient treatment and insurance settlement data were drawn from the Hospital Information System (HIS) and Insurance Settlement System (ISS). A total of 765 consecutive patients and 14,477 inpatient medical records were included and analyzed. Their insurance status (6 subtypes), economic burden [total cost, out-of-pocket cost (OOP), reimbursement, reimbursement rate (RR)], and cost structures (operation/procedure, blood products, drug, simple treatment) were calculated respectively. Non-normally distributed costs were reported as the median and interquartile range (IQR). Wilcoxon test was used for univariate tests and generalized linear model with log link was used to explore the influencing factors.

Results

The insured patients who were treated in the location of insurance with instant reimbursement reported the highest total cost and reimbursement, while those who seek medical care cross-province with no instant reimbursement reported the lowest total cost and highest OOP payment. In terms of annual change, the total cost of children with leukemia decreased from 2015–2019 with stably increasing reimbursement rate. Blood products and drugs were the major components of total cost, but they decreased annually. Patients who received transplantation and treated across provinces were with a higher economic burden.

Conclusion

The economic burden for children with leukemia decreased overtime under the protection of RBMI, but disparities exist among subtypes. The payer-provider contract on instant reimbursement and drug cost control are effective measures for insurance administrators to curb the economic burdens of pediatric leukemia treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07564-8.

Dynamin inhibition causes context-dependent cell death of leukemia and lymphoma cells

Current chemotherapy for treatment of pediatric acute leukemia, although generally successful, is still a matter of concern due to treatment resistance, relapses and life-long side effects for a subset of patients. Inhibition of dynamin, a GTPase involved in clathrin-mediated endocytosis and regulation of the cell cycle, has been proposed as a potential anti-cancer regimen, but the effects of dynamin inhibition on leukemia cells has not been extensively addressed. Here we adopted single cell and whole-population analysis by flow cytometry and live imaging, to assess the effect of dynamin inhibition (Dynasore, Dyngo-4a, MitMAB) on pediatric acute leukemia cell lines (CCRF-CEM and THP-1), human bone marrow biopsies from patients diagnosed with acute lymphoblastic leukemia (ALL), as well as in a model of lymphoma (EL4)-induced tumor growth in mice. All inhibitors suppressed proliferation and induced pronounced caspase-dependent apoptotic cell death in CCRF-CEM and THP-1 cell lines. However, the inhibitors showed no effect on bone marrow biopsies, and did not prevent EL4-induced tumor formation in mice. We conclude that dynamin inhibition affects highly proliferating human leukemia cells. These findings form a basis for evaluation of the potential, and constraints, of employing dynamin inhibition in treatment strategies against leukemia and other malignancies.

Novel Markers in Pediatric Acute Lymphoid Leukemia: The Role of ADAM6 in B Cell Leukemia

Background

The extensive genetic heterogeneity found in the B cell precursor acute lymphoblastic leukemia (BCP-ALL) subtype of childhood ALL represents a potential repository of biomarkers. To explore this potential, we have carried out in silico analysis of publicly available ALL datasets to identify genetic biomarkers for childhood BCP-ALL, which could be used either individually or in combination as markers for early detection, risk stratification, and prognosis.

Methods

To explore novel genes that show promising clinical and molecular signatures, we examined the cBioPortal online tool for publicly available datasets on lymphoid cancers. Three studies on lymphoblastic and lymphoid leukemia with 1706 patients and 2144 samples of which were identified. Only B-Lymphoblastic Leukemia/Lymphoma samples (n = 1978) were selected for further analysis. Chromosomal changes were assessed to determine novel genomic loci to analyze clinical and molecular profiles for the leukemia of lymphoid origin using cBioPortal tool.

Results

ADAM6 gene homozygous deletions (HOM:DEL) were present in 59.60% of the profiled patients and were associated with poor ten years of overall patients’ survival. Moreover, patients with ADAM6 HOM:DEL showed a distinguished clinical and molecular profile with higher Central Nervous System (CNS) sites of relapse. In addition, ADAM6 HOM:DEL was significantly associated with unique microRNAs gene expression patterns.

Conclusion

ADAM6 has the potential to be a novel biomarker for the development and progress of BCP- ALL.

Effectiveness and Safety of Clofarabine Monotherapy or Combination Treatment in Relapsed/Refractory Childhood Acute Lymphoblastic Leukemia: A Pragmatic, Non-interventional Study in Korea

Purpose

Effectiveness and safety of clofarabine (one of the treatment mainstays in pediatric patients with relapsed/refractory acute lymphoblastic leukemia [ALL]) was assessed in Korean pediatric patients with ALL to facilitate conditional coverage with evidence development.

Materials and Methods

In this multicenter, prospective, observational study, patients receiving clofarabine as mono/combination therapy were followed up every 4–6 weeks for 6 months or until hematopoietic stem cell transplantation (HSCT). Response rates, survival outcomes, and adverse events were assessed.

Results

Sixty patients (2–26 years old; 65% B-cell ALL, received prior ≥ 2 regimen, 68.3% refractory to previous regimen) were enrolled and treated with at least one dose of clofarabine; of whom 26 (43.3%) completed 6 months of follow-up after the last dose of clofarabine. Fifty-eight patients (96.7%) received clofarabine combination therapy. Overall remission rate (complete remission [CR] or CR without platelet recovery [CRp]) was 45.0% (27/60; 95% confidence interval [CI], 32.4 to 57.6) and the overall response rate (CR, CRp, or partial remission [PR]) was 46.7% (28/60; 95% CI, 34.0 to 59.3), with 11 (18.3%), 16 (26.7%), and one (1.7%) patients achieving CR, CRp, and PR, respectively. The median time to remission was 5.1 weeks (95% CI, 4.7 to 6.1). Median duration of remission was 16.6 weeks (range, 2.0 to 167.6 weeks). Sixteen patients (26.7%) proceeded to HSCT. There were 24 deaths; 14 due to treatment-emergent adverse events.

Conclusion

Remission with clofarabine was observed in approximately half of the study patients who had overall expected safety profile; however, there was no favorable long-term survival outcome in this study.

Upfront Therapies and Downstream Effects: Navigating Late Effects in Childhood Cancer Survivors in the Current Era

PURPOSE OF REVIEW

As survival rates of those diagnosed with childhood cancer improve over time, the number of long-term survivors continues to grow. Advances have not only been made in the upfront treatment of childhood cancer, but also in the identification and treatment of late complications that may arise as a result of the chemotherapy, radiotherapy, or surgical interventions required to provide a cure.

RECENT FINDINGS

As new therapies emerge that are often more targeted to cancerous cells while sparing healthy tissues, the hope is that cure can be achieved without the same long-term side effects for survivors. However, much is unknown regarding how these novel interventions will impact patients in the years to come. It is critical that we continue to follow patients treated with new modalities in order to identify and treat the long-term complications that may arise in future childhood cancer survivors.

Establishment and characterization of a novel childhood acute lymphoblastic leukemia cell line, HXEX-ALL1, with chromosome 9p and 17p deletions

Background

Although contemporary chemotherapy has improved the cure rate of childhood acute lymphoblastic leukemia (ALL) to nearly 90%, relapsed/refractory ALL is still a leading cause of tumor-related death in children. To clarify the underlying mechanisms of relapsed/refractory childhood ALL, researchers urgently need to establish novel cell models from patients with relapsed ALL after treatment with contemporary chemotherapy.

Methods

Cell culture technique was used to establish the HXEX-ALL1 cell line from primary B cell precursor ALL (BCP-ALL) cells. Molecular and cellular biological techniques including flow cytometry, polymerase chain reaction (PCR), short tandem repeat (STR) analysis, conventional cytogenetics, and chromosomal microarray analysis (CMA) were used to characterize the HXEX-ALL1 cell line. Nude mice were used for xenograft studies.

Results

A stable ALL cell line, HXEX-ALL1, derived from a 6-year-old boy of Han nationality with BCP-ALL at the second relapse, was established and maintained in culture for more than 18 months. The HXEX-ALL1 cell line was authenticated as being derived from primary leukemia cells based on morphologic, immunophenotypic, cytogenetic and STR analyses and demonstrated tumorigenicity in nude mice. WGS data showed that there were 27,006 novel single nucleotide polymorphisms (SNPs) and 193,951 novel insertion/deletions (InDels) in HXEX-ALL1 cells. Compared with the other BCP-ALL cell lines in use, the HXEX-ALL1 cells have a special karyotype represented by trisomy 8 and 9p and 17p deletions with a multidrug resistance phenotype, especially highly resistant to asparaginase.

Conclusions

The HXEX-ALL1 cell line may prove to be a useful model for the study of relapsed/refractory childhood ALL, particularly for the researches on asparaginase resistance.

Glutathione S-Transferase M1 and T1 Gene Deletions and Susceptibility to Acute Lymphoblastic Leukemia (ALL) in adults

Objective:

Biotransformation of xenobiotics are critical for their metabolism and removal from the body which is carried out by xenobiotic metabolizing enzymes. Individuals carrying variants of genes that encode these enzymes have an altered ability to metabolize xenobiotics which may lead to an increased risk of acute lymphoblastic leukemia. The current study aimed to investigate the impact of GSTM1 and GSTT1 gene deletions in causing predisposition to adult ALL.

Methods:

The current case-control study involved 62 adult ALL patients and 62 age and gender matched healthy controls. Whole blood samples processed with standard phenol chloroform protocol for DNA isolation were genotyped using multiplex PCR approach for simultaneous identification of GSTM1 and GSTT1 deletions. The genotype frequency obtained for patients was compared to controls using odds ratio and chi-square.

Results:

The null genotype frequency of GSTM1 and GSTT1 in a group of adult ALL patients from Pakistan were 47% and 11% respectively. Deletion of GSTM1 and GSTT1 did not show statistically significant association with adult ALL (p=0.86 and p=0.35 respectively). The combined GSTM1/GSTT1 deletion was observed in 2% patients and was not significantly associated with ALL in adults (p=0.85).

Conclusions:

The results reveal that homozygous null polymorphism of GSTM1 and GSTT1genes does not influence ALL susceptibility among adult patients. Cancer susceptibility associated with GST polymorphism varies with ethnic and geographic differences. Therefore, further investigation on different populations is needed to understand the role of these genetic variations in modifying adult ALL risk.

Non-infectious chemotherapy-associated acute toxicities during childhood acute lymphoblastic leukemia therapy

During chemotherapy for childhood acute lymphoblastic leukemia, all organs can be affected by severe acute side effects, the most common being opportunistic infections, mucositis, central or peripheral neuropathy (or both), bone toxicities (including osteonecrosis), thromboembolism, sinusoidal obstruction syndrome, endocrinopathies (especially steroid-induced adrenal insufficiency and hyperglycemia), high-dose methotrexate-induced nephrotoxicity, asparaginase-associated hypersensitivity, pancreatitis, and hyperlipidemia. Few of the non-infectious acute toxicities are associated with clinically useful risk factors, and across study groups there has been wide diversity in toxicity definitions, capture strategies, and reporting, thus hampering meaningful comparisons of toxicity incidences for different leukemia protocols. Since treatment of acute lymphoblastic leukemia now yields 5-year overall survival rates above 90%, there is a need for strategies for assessing the burden of toxicities in the overall evaluation of anti-leukemic therapy programs.