Survival of Mexican Children with Acute Lymphoblastic Leukaemia under Treatment with the Protocol from the Dana-Farber Cancer Institute 00-01

The genetic risk of acute lymphoblastic leukemia and its implications for children of Latin American origin

Acute lymphoblastic leukemia (ALL) is the most common cancer in children, and disproportionately affects children of Hispanic/Latino ethnicity in the United States, who have the highest incidence of disease compared with other racial/ethnic groups. Incidence of childhood ALL is similarly high in several Latin American countries, notably in Mexico, and of concern is the rising incidence of childhood ALL in some Hispanic/Latino populations that may further widen this disparity. Prior studies have implicated common germline genetic variants in the increased risk of ALL among Hispanic/Latino children. In this review, we describe the known disparities in ALL incidence as well as patient outcomes that disproportionately affect Hispanic/Latino children across the Americas, and we focus on the role of genetic variation as well as Indigenous American ancestry in the etiology of these disparities. Finally, we discuss future avenues of research to further our understanding of the causes of the disparities in ALL incidence and outcomes in children of Latin American origin, which will be required for future precision prevention efforts.

Lower Respiratory Infections in Children With Febrile Neutropenic Leukemia: A Case in a Jordanian Hospital

The study aimed to examine the prevalence of pneumonia in pediatric children diagnosed with leukemia at King Hussein Medical Center, Royal Medical Services, Amman, Jordan. The study was conducted from January 2019 to March 2020. A total of 100 hospitalized leukemia patients with febrile neutropenic episodes were evaluated for the presence of pneumonia. Samples were collected from all patients and tested for microbial growth. Univariate analysis revealed that age (P = .033) and packed cell volume (P = .006) were statistically significant risk factors, associated with the prevalence of pneumonia in leukemia patients with febrile neutropenia episodes. Similarly, as the absolute neutrophil count counts increased with an odds ratio and a 95% confidence interval of 2.386 (0.859-6.625), the odds of pneumonia in febrile neutropenic patients were more prevalent. The study reported the prevalence of pneumonia in immunocompromised febrile neutropenic patients with leukemia, which could lead to the development of evidence-based febrile neutropenic treatment protocol development. It will assure more responsive patient management and treatment.

Survival estimates of childhood malignancies treated at the Mexican telethon pediatric oncology hospital

BACKGROUND

Pediatric cancer incidence in Mexico is ~160/million/year with leukemias making 49.8% of the cases. While survival rates have been reported in various Mexican studies, no data is available from the Telethon Pediatric Oncology Hospital-HITO, a nonprofit private institution specialized exclusively in comprehensive pediatric oncology care in the country that closely follows high-income countries' advanced standards of cancer care.

AIM

To determine overall survival (OS) and relapse-free survival (RFS) in patients treated at HITO between December 2013 and February 2018.

METHODS AND RESULTS

Secondary analysis of data extracted from medical records. It included 286 children aged 0-17 years diagnosed with various cancers grouped into three categories based on location: (1) Acute lymphoblastic leukemia (ALL), (2) tumors within the central nervous system (TWCNS), and (3) tumors outside the CNS (TOCNS). OS and RFS rates for patients who completed 1 (n = 230) and 3 (n = 132) years of follow-up after admission were computed by sex, age, and cancer location, and separately for a subsample (1-year = 191, 3-years = 110) who fulfilled the HITO criteria (no prior treatment, underwent surgery/chemotherapy when indicated, and initiated therapy). TOCNS accounted for 45.1%, but ALL was the most frequent single diagnosis with 28%. Three-year OS for patients with ALL, TWCNS, and TOCNS who fulfilled the HITO criteria were 91.9%, 86.7%, and 79.3%, respectively; for 3-year RFS these were 89.2%, 60%, and 72.4%. Boys showed slightly higher OS and RFS, but no major differences or trends were seen by age group.

CONCLUSION

This study sets a relevant reference in terms of survival and relapse for children with cancer in Mexico treated at a private oncology center that uses a comprehensive and integrated therapeutic model.

Costs associated with adverse events from remission induction for children with Acute Lymphoblastic Leukemia (ALL)

Background

ALL is the most frequent hematological tumor in children, so during remission induction chemotherapy protocol (RICP) adverse events (AEs) may appear. The public program in Mexico in charge of financial support to oncologic children without social security delivered a fix amount for ALL chemotherapy, but additional money needed to treat any other unexpected condition should be taken from the budget of the oncologic healthcare providers. So the purpose of our study was to estimate and evaluate the direct medical costs associated to EAs during RICP in children with ALL.

Methods

This study was retrospective, longitudinal, and observational based on medical records review of patients in RICP. The CTCAE was used to identify and classify AEs according to a SOC category. We focused on extracting resources data that were consumed both for inpatients and outpatients AEs. A micro-costing approach was adopted which involve quantification of each healthcare resource consumed by the hospital multiplying them by unit cost. The probability distributions of data were evaluated to identify the appropriated statistical tests to be used for comparisons between groups that were performed with Wilcoxon rank sum test. Generalized linear models (GLM) were adjusted to evaluate the effects of patient characteristics on total cost.

Results

Forty patients accumulated 204 inpatient and 81 outpatient AEs during RICP. Comparison of total costs between groups showed an incremental cost of $7,460.23 likewise attributable to AEs. The total cost of a pediatric patient undergoing RICP without adverse events was $3,078.36 and the total cost of a patient with AEs exceeds it threefold.

Conclusions

The costs associated with AEs during RICP in Mexican children with ALL representing a high burden for the healthcare provider. Generalized linear models showed that variables such as sex, risk category and alive status are associated with the total costs of AEs. This is the first study aiming to analyze the effect of ALL-related AEs on health care costs in pediatric population, so our results may help not only to local decision making but also it may contribute to the research agenda in this field.

Triple-hit explanation for the worse prognosis of pediatric acute lymphoblastic leukemia among Mexican and Hispanic children

Acute lymphoblastic leukemia (ALL) is the most common malignancy among Mexican and Hispanic children and the first cause of death by disease in Mexico. We propose a "triple-hit" explanation for the survival gap affecting this population. The first hit can be attributed to epidemiology and social, cultural, and economic burdens. The second hit refers to cancer biology, with a high incidence of unfavorable genetic characteristics associated with an unfavorable response to treatment and, subsequently, poor survival. Finally, the third hit relates to sub-optimal treatment and support. Society and culture, leukemia biology, and treatment approach limitations are key factors that should not be seen apart and must be considered comprehensively in any strategy to improve the prognosis of Mexican and Hispanic children with ALL.

Childhood Cancer Survival, 2006-2012 Cohorts of Mexican Institute of Social Security Beneficiaries at the Central-South Region of Mexico

Introduction

In Mexico, the main institution of social security is the “Instituto Mexicano del Seguro Social” (IMSS), with more than 60 million enrolled individuals. This study of childhood cancer survival is the first based on complete cohorts of incident cases for the population IMSS- affiliated in the central-south region, which represents 27% of all children IMSS affiliated.

Methods

It is an observational cohort study from 2006 to 2012 to estimate the 5-year observed survival of the minors under 18 years old, identified in the Central-South Region Registry of Children with Cancer. The survival of cases was carried out through the active and passive search. Survival rates were estimated by the Kaplan–Meier (KM) method, the analysis of equality of survival functions was evaluated for some clinical variables.

Results

The study included 2,357 minors; the 5-year observed survival was 56.1% with a time of survival median of 3.4 years, and the overall loss of follow-up was 18.4%. The 5-year survival in cases with a diagnosis of leukemia was 53.5%, while for solid tumors, it was 57.9%. The median time of death was 1 year. The types of cancer with a survival greater than 70% were group V-retinoblastoma (87.2%), IIa-Hodgkin’s lymphoma (86.8%), Xc- gonadal tumors (83.3%), Iid-miscellaneous lymphomas (80%), IVa-nephroblastoma (79.5%), and IIc-Burkitt’s lymphoma (75.4%). Meanwhile, the lowest survival rates were in group VIII-bone tumors (32.3%), III-CNS (central nervous system; 44.1%), and IX-soft tissues (46.8%).

Conclusions

Survival results in the 2006–2012 cohorts show a significant gap in relation to the goal of 60% proposed by the World Health Organization for 2030.

Underexpression of LINC00173 in TCF3/PBX1-Positive Cases Is Associated With Poor Prognosis in Children With B-Cell Precursor Acute Lymphoblastic Leukemia

Background

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most frequent pediatric cancer worldwide. Despite improvements in treatment regimens, approximately 20% of the cases cannot be cured, highlighting the necessity for identifying new biomarkers to improve the current clinical and molecular risk stratification schemes. We aimed to investigate whether LINC00173 is a biomarker in ALL and to explore its expression level in other human cancer types.

Methods

A nested case-control study including Mexican children with BCP-ALL was conducted. LINC00173 expression was evaluated by qRT-PCR using hydrolysis probes. To validate our findings, RNA-seq expression data from BCP-ALL and normal tissues were retrieved from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Genotype-Tissue Expression (GTEx) repositories, respectively. LINC00173 expression was also evaluated in solid tumors by downloading available data from The Cancer Genome Atlas (TCGA).

Results

A lower expression of LINC00173 in BCP-ALL cases compared to normal subjects was observed (p < 0.05). ALL patients who carry the TCF3/PBX1 fusion gene displayed lower expression of LINC00173 in contrast to other BCP-ALL molecular subtypes (p < 0.04). LINC00173 underexpression was associated with a high risk to relapse (HR = 1.946, 95% CI = 1.213-3.120) and die (HR = 2.073, 95% CI = 1.211-3.547). Patients with TCF3/PBX1 and underexpression of LINC00173 had the worst prognosis (DFS: HR = 12.24, 95% CI = 5.04-29.71; OS: HR = 11.19, 95% CI = 26-32). TCGA data analysis revealed that underexpression of LINC00173 is also associated with poor clinical outcomes in six new reported tumor types.

Conclusion

Our findings suggest that LINC00173 is a biomarker of poor prognosis in BCP-ALL and other types of cancer. We observed an association between the expression of LINC00173 and TCF3/PBX1 and the risk to relapse and die in BCP-ALL, which is worse in TCF3/PBX1-positive cases displaying underexpression of LINC00173. Experimental studies are needed to provide insight into the LINC00173 and TCF3/PBX relationship.

Low Prevalence of ETV6::RUNX1 Fusion Gene in a Hispanic Population

ETV6::RUNX1 is a genetic rearrangement of good prognosis in children with acute lymphoblastic leukemia (ALL). In Mexico, its prevalence is low in comparison with Caucasian populations. We developed a novel TaqMan one-step RT-qPCR approach to assess the prevalence of four genetic rearrangements in a cohort of Hispanic children with ALL from Mexico City. The prevalence of common fusion gene transcripts was as follows: TCF3::PBX1 7.7%; BCR::ABL1p 190 3.3%; and KMT2A::AFF1 2.8%, and ETV6::RUNX1was observed with low prevalence (10.5%) in comparison to that reported for developed countries. This is consistent with previous findings on Mexican children with ALL and similar to those reported on children from Hispanic populations. The confirmation of a low prevalence of ETV6::RUNX1 in children of a Hispanic origin represents an advancement in the description of genetic factors of ALL in these populations.

Mapping Pediatric Oncology Clinical Trial Collaborative Groups on the Global Stage

The global pediatric oncology clinical research landscape, particularly in Central and South America, Africa, and Asia, which bear the highest burden of global childhood cancer cases, is less characterized in the literature. Review of how existing pediatric cancer clinical trial groups internationally have been formed and how their research goals have been pursued is critical for building global collaborative research and data-sharing efforts, in line with the WHO Global Initiative for Childhood Cancer.

Local stakeholder engagement is necessary to collaborate with global pediatric cancer trial groups.

Association Analysis Between the Functional Single Nucleotide Variants in miR-146a, miR-196a-2, miR-499a, and miR-612 With Acute Lymphoblastic Leukemia

Background

Acute lymphoblastic leukemia (ALL) is characterized by an abnormal proliferation of immature lymphocytes, in whose development involves both environmental and genetic factors. It is well known that single nucleotide polymorphisms (SNPs) in coding and noncoding genes contribute to the susceptibility to ALL. This study aims to determine whether SNPs in miR-146a, miR-196a-2, miR-499a, and miR-612 genes are associated with the risk to ALL in pediatric Mexican population.

Methods

A multicenter case-control study was carried out including patients with de novo diagnosis of ALL and healthy subjects as control group. The DNA samples were obtained from saliva and peripheral blood, and the genotyping of rs2910164, rs12803915, rs11614913, and rs3746444 was performed using the 5′exonuclease technique. Gene-gene interaction was evaluated by the multifactor dimensionality reduction (MDR) software.

Results

miR-499a rs3746444 showed significant differences among cases and controls. The rs3746444G allele was found as a risk factor to ALL (OR, 1.6 [95% CI, 1.05–2.5]; p = 0.028). The homozygous GG genotype of rs3746444 confers higher risk to ALL than the AA genotype (OR, 5.3 [95% CI, 1.23–23.4]; p = 0.01). Moreover, GG genotype highly increases the risk to ALL in male group (OR, 17.6 [95% CI, 1.04–298.9]; p = 0.00393). In addition, an association in a gender-dependent manner among SNPs located in miR-146a and miR-196a-2 genes and ALL susceptibility was found.

Conclusion

Our findings suggest that SNP located in miR-499a, miR-146a, and miR-196a-2 genes confer risk to ALL in Mexican children. Experimental analysis to decipher the role of these SNPs in human hematopoiesis could improve our understanding of the molecular mechanism underlying the development of ALL.

Mechanisms of Immunosuppressive Tumor Evasion: Focus on Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a malignancy with high heterogeneity in its biological features and treatments. Although the overall survival (OS) of patients with ALL has recently improved considerably, owing to the application of conventional chemo-therapeutic agents, approximately 20% of the pediatric cases and 40-50% of the adult patients relapse during and after the treatment period. The potential mechanisms that cause relapse involve clonal evolution, innate and acquired chemoresistance, and the ability of ALL cells to escape the immune-suppressive tumor response. Currently, immunotherapy in combination with conventional treatment is used to enhance the immune response against tumor cells, thereby significantly improving the OS in patients with ALL. Therefore, understanding the mechanisms of immune evasion by leukemia cells could be useful for developing novel therapeutic strategies.

Treatment of childhood acute lymphoblastic leukemia in Iraq: a 17-year experience from a single center

We performed a retrospective analysis of 1415 acute lymphoblastic leukemia children diagnosed between January 2000 and December 2016 at Children Welfare Teaching Hospital, Baghdad, Iraq. Patients were divided into three cohorts according to treatment period (2000-2005; 2006-2011; 2012-2016). Treatments were based on modified-UKALL protocols; a steroid-pre-phase was introduced from September 2008. The overall complete remission was 86%, increased from 80% to 91% in the last period. Early deaths occurred in 10%, decreasing to 6%, overtime. Relapses were 23%; toxic deaths and abandonment 8% and 13%, respectively. At a median follow-up of 65.3 months, with abandonment considered as an event, the 5-year overall survival (OS) and event-free survival were 62.2% and 46.3%, statistically influenced by treatment period (5-year OS 62.6%, 59.1%, 66.3%; p=.057, respectively). Though pediatric ALL survival in Iraq is still below that observed in high income countries, survival rates progressively improved. Toxic deaths remain an important cause of failure.

Identification of a nomogram based on an 8-lncRNA signature as a novel diagnostic biomarker for childhood acute lymphoblastic leukemia

Childhood acute lymphoblastic leukemia (cALL) still represents a major cause of disease-related death in children. This study aimed to explore the prognostic value of long non-coding RNAs (lncRNAs) in cALL. We downloaded lncRNA expression profiles from the TARGET and GEO databases. Univariate, least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analyses were applied to identify lncRNA-based signatures. We identified an eight-lncRNA signature (LINC00630, HDAC2-AS2, LINC01278, AL356599.1, AC114490.1, AL132639.3, FUT8.AS1, and TTC28.AS1), which separated the patients into two groups with significantly different overall survival rates. A nomogram based on the signature, BCR ABL1 status and white blood cell count at diagnosis was developed and showed good accuracy for predicting the 3-, 5- and 7-year survival probability of cALL patients. The C-index values of the nomogram in the training and internal validation set reached 0.8 (95% CI, 0.757 to 0.843) and 0.806 (95% CI, 0.728 to 0.884), respectively. The nomogram proposed in this study objectively and accurately predicted the prognosis of cALL. In vitro experiments suggested that LINC01278 promoted the proliferation of leukemic cells and inhibited leukemic cell apoptosis by targeting the inhibition of miR-500b-3p in cALL, and LINC01278 may be a biological target for the treatment of cALL in the future.

Copy Number Alterations are Associated with the Risk of Very Early Relapse in Pediatric B-lineage Acute Lymphoblastic Leukemia: A Nested Case-control MIGICCL Study

BACKGROUND

Refining risk stratification to avoid very early relapses (VER) in Mexican patients with B-lineage acute lymphoblastic leukemia (B-ALL) could lead to better survival rates in our population.

AIM OF THE STUDY

The purpose of this study was to investigate the association between the United Kingdom ALL (UKALL)-CNA classifier and VER risk in Mexican patients with childhood B-ALL.

METHODS

A nested case-control study of 25 cases with VER and 38 frequency-matched controls without relapse was conducted within the MIGICCL study cohort. They were grouped into the categories of the UKALL-CNA risk classifier (good [reference], intermediate and poor), according to the results obtained by multiplex ligation dependent probe amplification. Overall and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards analyses were conducted.

RESULTS

The CDKN2A/B genes were most frequently deleted in the group with relapse. According to UKALL-CNA classifier, 33 (52.4%) patients were classified as good, 21 (33.3%) intermediate and 9 (14.3%) poor-risk B-ALL. The intermediate and poor risk groups were associated with an increased risk of VER (HR = 4.94, 95% CI = 1.87-13.07 and HR = 7.42, 95% CI = 2.37-23.26, respectively) in comparison to the good-risk patients. After adjusting by NCI risk classification and chemotherapy scheme in a multivariate model, the risks remained significant.

CONCLUSIONS

Our data support the clinical utility of profiling CNAs to potentially refine current risk stratification strategies of patients with B-ALL.

Promising genes and variants to reduce chemotherapy adverse effects in acute lymphoblastic leukemia

Almost two decades ago, the sequencing of the human genome and high throughput technologies came to revolutionize the clinical and therapeutic approaches of patients with complex human diseases. In acute lymphoblastic leukemia (ALL), the most frequent childhood malignancy, these technologies have enabled to characterize the genomic landscape of the disease and have significantly improved the survival rates of ALL patients. Despite this, adverse reactions from treatment such as toxicity, drug resistance and secondary tumors formation are still serious consequences of chemotherapy, and the main obstacles to reduce ALL-related mortality. It is well known that germline variants and somatic mutations in genes involved in drug metabolism impact the efficacy of drugs used in oncohematological diseases therapy. So far, a broader spectrum of clinically actionable alterations that seems to be crucial for the progression and treatment response have been identified. Although these results are promising, it is necessary to put this knowledge into the clinics to help physician make medical decisions and generate an impact in patients' health. This review summarizes the gene variants and clinically actionable mutations that modify the efficacy of antileukemic drugs. Therefore, knowing their genetic status before treatment is critical to reduce severe adverse effects, toxicities and life-threatening consequences in ALL patients.

Genetic markers for treatment-related pancreatitis in a cohort of Hispanic children with acute lymphoblastic leukemia

PURPOSE

Treatment-related pancreatitis (TRP) is a serious complication occurring in children with acute lymphoblastic leukemia (ALL). Those affected are at high risk for severe organ toxicity and treatment delays that can impact outcomes. TRP is associated with asparaginase, a standard therapeutic agent in childhood ALL. Native American ancestry, older age, high-risk leukemia, and increased use of asparaginase are linked to pancreatitis risk. However, dedicated genetic studies evaluating pancreatitis in childhood ALL include few Hispanics. Thus, the genetic basis for higher risk of pancreatitis among Hispanic children with ALL remains unknown.

METHODS

Cases of children with ALL treated in from 1994 through 2013 were reviewed and identified 14, all Hispanic, who developed pancreatitis related to asparaginase therapy. Forty-six controls consisting of Hispanic children treated on the same regimens without pancreatitis were selected for comparison. Total DNA isolated from whole blood was used for targeted DNA sequencing of 23 selected genes, including genes associated with pancreatitis without ALL and genes involved in asparagine metabolism.

RESULTS

Non-synonymous polymorphisms and frameshift deletions were detected in 15 genes. Most children with TRP had variants in ABAT, ASNS, and CFTR. Notably, children with TRP harbored many more CFTR variants (71.4%) compared with controls (39.1%). Among these, V470M (rs213950) was most frequent (OR 4.27, p = 0.025).

CONCLUSIONS

This is the first study of genetic factors in treatment-related pancreatitis in Hispanic children with ALL. Identifying correlative variants in ethnically vulnerable populations may improve screening to identify which patients with ALL are at greatest risk for pancreatitis.

Transcriptome Analysis Identifies LINC00152 as a Biomarker of Early Relapse and Mortality in Acute Lymphoblastic Leukemia

Evidence showing the role of long non-coding RNAs (lncRNAs) in leukemogenesis have emerged in the last decade. It has been proposed that these genes can be used as diagnosis and/or prognosis biomarkers in childhood acute lymphoblastic leukemia (ALL). To know if lncRNAs are associated with early relapse and early mortality, a microarray-based gene expression analysis in children with B-lineage ALL (B-ALL) was conducted. Cox regression analyses were performed. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated. LINC00152 and LINC01013 were among the most differentially expressed genes in patients with early relapse and early mortality. For LINC00152 high expression, the risks of relapse and death were HR: 4.16 (95% CI: 1.46–11.86) and HR: 1.99 (95% CI: 0.66–6.02), respectively; for LINC01013 low expression, the risks of relapse and death were HR: 3.03 (95% CI: 1.14–8.05) and HR: 6.87 (95% CI: 1.50–31.48), respectively. These results were adjusted by NCI risk criteria and chemotherapy regimen. The lncRNA–mRNA co-expression analysis showed that LINC00152 potentially regulates genes involved in cell substrate adhesion and peptidyl–tyrosine autophosphorylation biological processes. The results of the present study point out that LINC00152 could be a potential biomarker of relapse in children with B-ALL.

Treatment outcomes of children with acute lymphoblastic leukemia in a middle-income developing country: high mortalities, early relapses, and poor survival

OBJECTIVE

Acute lymphoblastic leukemia is the most common childhood cancer, yet surprisingly, very few studies have reported the treatment outcomes and the relapse rate of patients from low/middle-income countries.

METHOD

This study was a 5-year retrospective cohort study. It was conducted at Oncology Center of Mansoura University in Egypt and aimed to estimate the treatment outcomes and the relapse rates of newly diagnosed acute lymphoblastic leukemia in children.

RESULTS

Two hundred children suffering from acute lymphoblastic leukemia were studied; forty-six patients (23%) died during induction and most of those deaths were related to infection. Forty-one patients (27%) relapsed out of the 152 patients who achieved complete remission. The most common site of relapse was the bone marrow, followed by the isolated central nervous system, 53.7% and 31.7%, respectively. Seventy-eight percent of relapses occurred very early/early rather than later. The majority of relapse patients' deaths were related to infection and disease progression. The 5-year overall survival rate for patients was 63.1% (82.1% for non-relapsed compared to 36.6% for relapsed patients).

CONCLUSION

There was a high incidence of induction deaths related to infection and high percentages of very early/early relapses, with high mortalities and low 5-year overall survival rates. These findings suggest the urgent need for modification of chemotherapy regimens to be suitable for the local conditions, including implementation of supportive care and infection control policies. There is also a requirement for antimicrobial prophylaxis during induction period combined with the necessary increase in government healthcare spending to improve the survival of acute lymphoblastic leukemia in Egyptian children.

Poor Prognosis Biomolecular Factors Are Highly Frequent in Childhood Acute Leukemias From Oaxaca, Mexico

OBJECTIVE

To investigate the cellular and molecular epidemiology of acute leukemias in vulnerable populations of children and adolescents in Oaxaca de Juarez, Mexico.

MATERIAL AND METHODS

Descriptive, cross-sectional and retrospective study, conducted from 2014 to 2018 in which profiles of molecular and immunophenotypic aberrations were investigated in children and adolescents diagnosed with acute leukemia, by evaluating 28 molecular abnormalities by HemaVision-Q28 multiplex RT-PCR kit and standardized EuroFlow Immunophenotyping of bone marrow cells.

RESULTS

We included 218 patients, with 82.5% younger than 14 years and 17.5% adolescents. The median age was 9 years and a main peak of incidence was recorded at age of 4 to 5 years. B-cell acute lymphoblastic leukemia was diagnosed in 70.64% of all cases, acute myeloid leukemia was in 22.48%, T-cell acute lymphoblastic leukemia in 6.42%, and mixed lineage acute leukemia in 0.46% of cases. Overall, chromosomal translocations were positive in 29.82% of cases. While 65.31% of patients with acute myeloid leukemia reported aberrancies, only in 18.83% of B-cell acute lymphoblastic leukemia cases genetic abnormalities were obvious. Surprisingly, most prevalent translocations in B-cell acute lymphoblastic leukemia were t(9;22) in 20.7%, followed by t(4;11) in 17.2% and t(6;11) in 13.8%, whereas patients with acute myeloid leukemia showed t(15;17) in 40.6% and t(8;21) in 21.9%. In contrast, an homogeneous expression of t(3;21) and t(6;11) was recorded for T-cell acute lymphoblastic leukemia and mixed lineage acute leukemia cases, respectively. Except for t(1;19), expressed only by pre-B cells, there was no association of any of the studied translocations with differentiation stages of the B-leukemic developmental pathway.

CONCLUSION

Our findings identify near 50% of patients with acute lymphoblastic leukemia at debut with high-risk translocations and poor prognosis in B-cell acute lymphoblastic leukemia as well as an unexpected increase of acute myeloid leukemia cases in young children, suggesting a molecular shift that support a higher incidence of poor prognosis cases in Oaxaca.

Overweight and obesity as predictors of early mortality in Mexican children with acute lymphoblastic leukemia: a multicenter cohort study

BACKGROUND

Mexico City has one of the highest incidences and mortality rates of acute lymphoblastic leukemia (ALL) in the world and a high frequency of early relapses (17%) and early mortality (15%). Otherwise, childhood overweight and obesity are reaching epidemic proportions. They have been associated with poor outcomes in children with ALL. The aim of present study was to identify if overweight and obesity are predictors of early mortality and relapse in Mexican children with ALL.

METHODS

A multicenter cohort study was conducted. ALL children younger than 15 years old were included and followed-up during the first 24 months after diagnosis. Overweight and obesity were classified according World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) criteria. Early mortality and early relapses were the main outcomes.

RESULTS

A total of 1070 children were analyzed. Overweight/obesity at diagnosis were predictors of early mortality (WHO: HR = 1.4, 95%CI:1.0-2.0; CDC: HR = 1.6, 95%CI:1.1-2.3). However, no associations between overweight (WHO: HR = 1.5, 95%CI:0.9-2.5; CDC: HR = 1.0; 95% CI:0.6-1.6) and obesity (WHO: HR = 1.5, 95%CI:0.7-3.2; CDC: HR = 1.4; 95%CI:0.9-2.3) with early relapse were observed.

CONCLUSIONS

Overweight and obese patients embody a subgroup with high risk of dying during leukemia treatment.

Socioeconomic inequalities in survival of children with acute lymphoblastic leukemia insured by social security in Mexico: a study of the 2007-2009 cohorts

BACKGROUND

Although acute lymphoblastic leukemia (ALL) 5 years survival in minors has reached 90%, socioeconomic differences have been reported among and within countries. Within countries, the difference has been related to the socioeconomic status of the parents, even in the context of public health services with universal coverage. In Mexico, differences in the mortality of children with cancer have been reported among sociodemographic zones. The Instituto Mexicano del Seguro Social (IMSS), the country's main social security institution, has reported socioeconomic differences in life expectancy within its affiliated population. Here, the socioeconomic inequalities in the survival of children (< 15 years old) enrolled in the IMSS were analyzed.

METHODS

Five-year survival data were analyzed in cohorts of patients diagnosed with ALL during the period 2007-2009 in the two IMSS networks of medical services that serve 7 states of the central region of Mexico. A Cox proportional risk model was developed and adjusted for the socioeconomic characteristics of family, community of residence and for the clinical characteristics of the children. The slope of socioeconomic inequality of the probability of dying within five years after the diagnosis of ALL was estimated.

RESULTS

For the 294 patients studied, the 5 years survival rate was 53.7%; the median survival was 4.06 years (4.9 years for standard-risk diagnosis; 2.5 years for high-risk diagnosis). The attrition rate was 12%. The Cox model showed that children who had been IMSS-insured for less than half their lives had more than double the risk of dying than those who had been insured for their entire lives.

CONCLUSIONS

We did not find evidence of socioeconomic inequalities in the survival of children with ALL associated with family income, educational and occupational level of parents. However, we found a relevant gradient related social security protection: the longer children's life insured by social security, the higher their probability of surviving ALL was. These results add evidence of the effectiveness of social security, as a mechanism of wealth redistribution and a promoter of social mobility. Extending these social security benefits to the entire Mexican population could promote better health outcomes.

Elements Associated With Early Mortality in Children With B Cell Acute Lymphoblastic Leukemia in Chiapas, Mexico: A Case-control Study

Childhood Lymphoblastic leukemia's (ALL) early mortality (EM) is an undesirable treatment outcome for a disease for which >90% long term success is achievable. In the Western world EM constitutes no >3%; yet, in Chiapas, Mexico, remains around 15%. With the objective of improving on EM, we determined associated elements in 28 ALL who died within 60 days of arriving at Hospital de Especialidades Pediátricas in Chiapas (HEP), by comparing them to those in 84 controls who lived beyond the first 90 days. χ, t test, and binary logistic regression (BLR) were used to determine significant individual and multiple variables associated to outcome. On arrival, fever, liver and spleen enlargement, active bleeding, lower albumin, less platelets, higher creatinine, and uric acid, more diploid and less hyperdiploid cases were associated with EM cases. Time to diagnosis, nutritional status, risk group and leukocyte count were not related. Antileukemic treatment approach was similar in both groups. The BLR model including fever, active bleeding, liver enlargement, <10,000 platelets/µL, and >2X upper normal lactic dehydrogenase, determined outcome in 66.7% EM and 90.2% controls. To improve on EM in ALL, patients with characteristics defined here ought to be treated differently at HEP.

A greater birthweight increases the risk of acute leukemias in Mexican children-experience from the Mexican Interinstitutional Group for the Identification of the Causes of Childhood Leukemia (MIGICCL)

In Mexico, due to the high rates of diabetes, overweight, and obesity, there has also been noted an increased newborn weight, which may be contributing to the elevated incidence rate of childhood acute leukemia (AL). We conducted a case-control study in public hospitals of Mexico City aimed to know whether a greater weight at birth is associated with a higher risk of developing leukemia. We included incident cases with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) diagnosed between 2010 and 2015. Controls were frequency-matched to the cases by age, sex, and health institution. Logistic regression analysis was performed adjusting risks by child's sex, overcrowding index, birth order, and mother's age at the time of pregnancy. Adjusted odds ratios (aORs) and 95% confidence intervals were calculated. A total of 1455 cases and 1455 controls were included. An evident association between ALL and child's birthweight ≥2500 g was found (aOR 2.06; 95% CI: 1.59, 2.66) and also, in those with birthweight ≥3500 g (aOR 1.19; 95% CI: 1.00, 1.41). In AML patients with birthweight ≥2500 g and ≥3500 g, an aOR of 1.77 (95% CI: 1.07, 2.94) and 1.42 (95% CI: 1.03-1.95) was observed, respectively. No association was noticed with either type of AL and a birthweight ≥4000 g. To sum up, we found a moderate association between not having a low birthweight and an increased risk of acute leukemias. Birthweight ≥3500 g was also a risk factor for both types of leukemia. This suggests that a greater birthweight may increase the risk of acute leukemias in Mexican children.

Omics techniques and biobanks to find new biomarkers for the early detection of acute lymphoblastic leukemia in middle-income countries: a perspective from Mexico

Acute lymphoblastic leukemia (ALL) affects the quality of life of many children in the world and particularly in Mexico, where a high incidence has been reported. With a proper financial investment and with well-organized institutions caring for those patients, together with solid platforms to perform high-throughput analyses, we propose the creation of a Mexican repository system of serum and cells from bone marrow and blood samples derived from tissues of pediatric patients with ALL diagnosis. This resource, in combination with omics technologies, particularly proteomics and metabolomics, would allow longitudinal studies, offering an opportunity to design and apply personalized ALL treatments. Importantly, it would accelerate the development of translational science and will lead us to further discoveries, including the identification of new biomarkers for the early detection of leukemia.

Hospitalization rate and costs in acute lymphoblastic leukemia of childhood in a low-income group: Financial impact in Northeast Mexico

BACKGROUND

Acute lymphoblastic leukemia (ALL) is one of the main and most expensive and prolonged causes of hospitalization for childhood cancer. We describe the hospitalization rate and its costs for an open population with ALL in a low-middle income country.

PROCEDURE

We retrospectively analyzed 449 hospital admissions for 101 pediatric patients with ALL over 8 years. Clinical files and electronic databases were scrutinized to document causes, duration, readmission rate, costs, and outcome of each admission. Hospitalizations were divided into two categories: general pediatric ward and pediatric intensive care unit (PICU). Hospitalization rates and its costs per patient were estimated considering person-time at risk.

RESULTS

Patients had an admission rate of 2.09 hospitalizations per patient-year and median length of stay per admission was 5 days. Most admissions occurred during the first 2 years from diagnosis. Mean cost per day was 239 US dollars (USD) and mean cost per stay was 2,246 USD versus 1,016 and 19,004 USD (P = 0.001) in the PICU, respectively. Total hospitalization cost per patient per year (PPPY) was 5,991 USD for high-risk patients and 3,038 USD for standard-risk patients. Patients between ages 1 and 9 years had a PPPY cost of $4,057; while for children younger than 1 year or older than 9 years, it was 7,463 USD. The popular medical insurance program covered 70% of hospitalizations and 63% of its total cost; patients contributed 2%, with the hospital absorbing 35%.

CONCLUSIONS

Hospitalizations for children with ALL were less expensive than in high-income countries but had a significant cost to low-income families and to the healthcare system.

Copy Number Alterations Associated with Acute Lymphoblastic Leukemia in Mexican Children. A report from The Mexican Inter-Institutional Group for the identification of the causes of childhood leukemia

B-cell precursor acute lymphocytic leukemia (B-ALL) represents a worldwide public health issue. Particularly, Mexico is one of the countries with the highest incidence of ALL in children. Between the multiple factors involved in ALL etiology, genetic alterations are clearly one of the most relevant features. In this work, a group of 24 B-ALL patients, all negative for the four most frequent gene fusions (ETV6-RUNX1, BCR-ABL1, TCF3-PBX1 and MLL-AF4), were included in a high-resolution microarray analysis in order to evaluate genomic copy-number alterations (CNAs). The results of this preliminary report showed a broad genomic heterogeneity among the studied samples; 58% of the patients were hyperdiploid and 33% displayed a chromosome 9p deletion of variable length affecting genes CDKN2A/B, two patients displayed genomic instability with a high number of focal CNAs, three patients presented unique duplications affecting 2q, 12p and 1q, respectively, and one patient displayed no copy number imbalances. The copy-number profile of 44 genes previously related to B-ALL was heterogeneous as well. Overall results highlight the need for a detailed description of the genetic alterations in ALL cancer cells in order to understand the molecular pathogenesis of the disease and to identify any prognostic markers with clinical significance.

Analysis of Thiopurine S-Methyltransferase Deficient Alleles in Acute Lymphoblastic Leukemia Patients in Mexican Patients

BACKGROUND AND AIMS

It has been demonstrated that heterozygote and homozygote thiopurine S-methyltransferase (TPMT) mutant allele carriers are at high risk to develop severe and potentially fatal hematopoietic toxicity after treatment with standard doses of 6-mercaptopurine (6-MP) and methotrexate (MX). Those drugs are the backbone of acute lymphoblastic leukemia (ALL) and several autoimmune disease treatments. We undertook this study to determine the frequency of the TPMT deficient alleles in children with ALL and non-ALL subjects from Mexico City and Yucatan, Mexico.

METHODS

We included 849 unrelated subjects, of which 368 ALL children and 342 non-ALL subjects were from Mexico City, and 60 ALL cases and 79 non-ALL individuals were from Yucatan. Genotyping of the rs1800462, rs1800460 and rs1142345 SNPs was performed by 5'exonuclease technique using TaqMan probes (Life Technologies Foster City, CA).

RESULTS

The mutant TPMT alleles were present in 4.8% (81/1698 chromosomes) and only 0.2% were homozygote TPMT*3A/TPMT*3A. We did not find statistically significant differences in the distribution of the mutant alleles between patients from Mexico City and Yucatan in either ALL cases or non-ALL. Nonetheless, the TPMT*3C frequency in ALL patients was higher than non-ALL subjects (p = 0.03). To note, the null homozygous TPMT*3A/TPMT*3A genotype was found in 2.5% of the non-ALL subjects.

CONCLUSIONS

TPMT mutant alleles did not exhibit differential distribution between both evaluated populations; however, TPMT*3C is overrepresented in ALL cases in comparison with non-ALL group. Assessing the TPMT mutant alleles could benefit the ALL children and those undergoing 6-MP and MX treatment.

Gene Expression Profiling of Acute Lymphoblastic Leukemia in Children with Very Early Relapse

BACKGROUND AND AIMS

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer worldwide. Mexican patients have high mortality rates, low frequency of good prognosis biomarkers (i.e., ETV6-RUNX1) and a high proportion is classified at the time of diagnosis with a high risk to relapse according to clinical features. In addition, very early relapses are more frequently observed than in other populations. The aim of the study was to identify new potential biomarkers associated with very early relapse in Mexican ALL children through transcriptome analysis.

METHODS

Microarray gene expression profiling on bone marrow samples of 54 pediatric ALL patients, collected at time of diagnosis and/or at relapse, was performed. Eleven patients presented relapse within the first 18 months after diagnosis. Affymetrix Human Transcriptome Array 2.0 (HTA 2.0) was used to perform gene expression analysis. Annotation and functional enrichment analyses were carried out using Gene Ontology, KEGG pathway analysis and Ingenuity Pathway Analysis tools.

RESULTS

BLVRB, ZCCHC7, PAX5, EBF1, TMOD1 and BLNK were differentially expressed (fold-change >2.0 and p value <0.01) between relapsed and non-relapsed patients. Functional analysis of abnormally expressed genes revealed their important role in cellular processes related to the development of hematological diseases, cancer, cell death and survival and in cell-to-cell signaling interaction.

CONCLUSIONS

Our data support previous findings showing the relevance of PAX5, EBF1 and ZCCHC7 as potential biomarkers to identify a subgroup of ALL children in high risk to relapse.

Age Acts as an Adverse Independent Variable for Survival in Acute Lymphoblastic Leukemia: Data From a Cohort in Northeast Mexico

BACKGROUND

Survival for acute lymphoblastic leukemia (ALL) decreases with age. Patients across all age groups from a homogeneous ethnic and socioeconomic background were studied to document age effect.

MATERIAL AND METHODS

Patients diagnosed from 2005 to 2015 at a university hospital in Northeast Mexico were divided into 4 age groups: infants (< 1), children (≥ 1 to < 16), adolescents (≥ 16 to ≤ 20), and adults (> 20 years). Correlation between age at diagnosis and relapse-free (RFS) and overall survival (OS) was investigated.

RESULTS

A total of 377 patients were included. Five-year RFS and OS for children were 55.6% and 66.9%; for adolescents, 36.0% and 48.3%; for adults, 19.5% and 24.1%, respectively. Differences in RFS and OS between age groups were significant (P < .001, P < .001). In the Cox regression model, all age groups reached statistical significance in univariate analysis of mortality.

CONCLUSION

Age plays a decisive role in clinical evolution of ALL and strongly influences outcome. Age older than 20 represents a progressive high-risk factor for death.

Relapse of childhood acute lymphoblastic leukemia and outcomes at a reference center in Latin America: organomegaly at diagnosis is a significant clinical predictor

OBJECTIVE

Relapse is the major cause of treatment failure in acute lymphoblastic leukemia (ALL) of childhood; it is more frequent among high-risk patients from low-middle income than from high-income countries. The frequency, sites and outcome of relapsed ALL in children of northeast Mexico over a decade was documented.

METHODS

A retrospective analysis of 246 children belonging to a low-income group <16 years with de novo ALL during 2004-2015 was performed. Five-year overall survival (OS) and event-free survival was estimated by Kaplan-Meier analysis. Data on time, site, response to therapy and final outcome of relapse were analyzed. Hazard ratios (HRs) of relapse and death were estimated by the Cox regression model. Very early relapse was defined as that occurring in <18 months, early relapse between 18 and 36 months, and late relapse >36 months from diagnosis, respectively.

RESULTS

Eighty-seven (35.4%) children relapsed. Five-year OS was 82.6% in children without relapse vs. 42% for relapsed patients. Bone marrow (BM) was the most frequent site of relapse (51.72%). Isolated central nervous system (CNS) relapses occurred in 29.9%. Five-year OS was 11.2% for BM and 15.5% for early relapse. HR of relapse for organomegaly was 3.683, 2.247 for an initial white blood cell count >50 000 × 10⁹/l and 1.169 for positive minimal residual disease status.

CONCLUSION

A high rate of very early, CNS, and BM relapse with a considerably low 5-year OS requiring reassessment of therapy was documented. Organomegaly at diagnosis was a highly significant clinical predictor for relapse.

Improving outcome of acute lymphoblastic leukemia with a simplified protocol: report from a tertiary care center in north India

BACKGROUND

The outcome of malignancies in low- and middle-income countries (LMICs) is hampered owing to numerous factors. Current protocols are complex, demanding supportive care, often not optimally available. We de-escalated the UKALL 2003 protocol to improve the outcome of acute lymphoblastic leukemia (ALL) at our center.

METHODS

In 2007-2009, children were treated as per the UKALL 2003 protocol (protocol 1). In 2010 and 2011, a modified version of the UKALL 2003 (protocol 2) was followed.

RESULTS

Three hundred and seventy-four children aged 5.71+3.1 (1-13) years were treated. Remission was achieved in 335 of the 338 who completed induction. Treatment-related mortality decreased significantly with the modified protocol (P ≤ 0.001). Relapses were similar with both protocols. Protocol used, regimen, counts at diagnosis, weight for age, gender, education of parents and occupation of caregiver were associated with the outcome of death (P < 0.05). On Cox proportional hazard analysis, patients on protocol 1, female gender and weight ≤5th centile had a greater hazard of dying (0.46 [P < 0.0001]; 1.5 [P = 0.04] and 1.64 [P = 0.01]). The 3 years overall survival (OS) with protocols 1 and 2 was 54.8% (95% CI 47.4-61.7%) and 73.9% (95% CI 66-79%) (P < 0.001), respectively. The event-free survival with protocols 1 and 2 was 50.8% (95% CI 43-57%) and 65.7% (95% CI 58-72%) (P < 0.001), respectively.

CONCLUSIONS

A steady improvement in survival has been observed at our center to a 3-year present OS of 73.9% with reduction in treatment intensity. The way forward for LMICs is to formulate rational treatment protocols at par with resources.

Adipokines, insulin resistance, and adiposity as a predictors of metabolic syndrome in child survivors of lymphoma and acute lymphoblastic leukemia of a developing country

BACKGROUND

There is a growing body of evidence indicating that pediatric survivors of cancer are at a greater risk of developing metabolic syndrome. This study evaluated some probable predictors of metabolic syndrome (MS), such as leptin and adiponectin concentrations, the leptin/adiponectin ratio, insulin resistance, and adiposity, in a sample of child survivors of lymphoma and leukemia in Mexico City.

METHODS

Fifty two children (leukemia n = 26, lymphoma n = 26), who were within the first 5 years after cessation of therapy, were considered as eligible to participate in the study. Testing included fasting insulin, glucose, adipokines and lipids; body fat mass was measured by DXA. The MS components were analyzed according to tertiles of adipokines, insulin resistance, and adiposity. Comparisons between continuous variables were performed according to the data distribution. The MS components were analyzed according to tertiles of adipokines, insulin resistance, and adiposity. With the purpose of assessing the risk of a present MS diagnosis, odds ratios (OR) with a 95% confidence interval (95% IC) were obtained using logistic regression analysis according to the various metabolic markers.

RESULTS

The median children age was 12.1 years, and the interval time from the completion of therapy to study enrollment was 4 years. Among the MS components, the prevalence of HDL-C low was most common (42%), followed by central obesity (29%). The HOMA-IR (OR 9.0, 95% CI 2.0; 41.1), body fat (OR 5.5, 95% CI 1.6; 19.3), leptin level (OR 5.7, 95% CI 1.6; 20.2) and leptin/adiponectin ratio (OR 9.4, 95% CI 2.0; 49.8) in the highest tertile, were predictive factors of developing MS; whereas the lowest tertile of adiponectin was associated with a protective effect but not significant.

CONCLUSIONS

Biomarkers such as HOMA-IR, leptin and leptin/adiponectin are associated with each of the components of the MS and with a heightened risk of suffering MS among children survivors of cancer. Given the close relationship between MS with risk of developing type 2 diabetes and cardiovascular disease, it is imperative to implement prevention measures in this population and especially in developing countries where these pathologies have become the leading cause of death.

Drugs under preclinical and clinical study for treatment of acute and chronic lymphoblastic leukemia

Targeted therapy has modernized the treatment of both chronic and acute lymphoblastic leukemia. The introduction of monoclonal antibodies and combinational drugs has increased the survival rate of patients. Preclinical studies with various agents have resulted in positive outputs with Phase III trial drugs and monoclonal antibodies entering clinical trials. Most of the monoclonal antibodies target the CD20 and CD22 receptors. This has led to the approval of a few of these drugs by the US Food and Drug Administration. This review focuses on the drugs under preclinical and clinical study in the ongoing efforts for treatment of acute and chronic lymphoblastic leukemia.