Racial and ethnic differences in survival of children with acute lymphoblastic leukemia

Concepts in B cell acute lymphoblastic leukemia pathogenesis

B cell acute lymphoblastic leukemia (B-ALL) arises from genetic alterations impacting B cell progenitors, ultimately leading to clinically overt disease. Extensive collaborative efforts in basic and clinical research have significantly improved patient prognoses. Nevertheless, a subset of patients demonstrate resistance to conventional chemotherapeutic approaches and emerging immunotherapeutic interventions. This review highlights the mechanistic underpinnings governing B-ALL transformation. Beginning with exploring normative B cell lymphopoiesis, we delineate the influence of recurrent germline and somatic genetic aberrations on the perturbation of B cell progenitor differentiation and protumorigenic signaling, thereby facilitating the neoplastic transformation underlying B-ALL progression. Additionally, we highlight recent advances in the multifaceted landscape of B-ALL, encompassing metabolic reprogramming, microbiome influences, inflammation, and the discernible impact of socioeconomic and racial disparities on B-ALL transformation and patient survival.

Effect of American genomic ancestry on severe toxicities in children with acute lymphoblastic leukemia in the Amazon region

BACKGROUND

Acute Lymphoblastic Leukemia (ALL) is a neoplasm of the hematopoietic system characterized by a clonal expansion of abnormal lymphocyte precursor cells. ALL is the most common form of cancer in children, but despite advances in treatment, it can still be fatal. Ethnic differences influence survival rates, and genomic ancestry plays an important role, especially in mixed-race populations such as Latin America. This study aims to analyze the influence of genomic ancestry on toxicity in children with ALL in the Amazon region.

METHODS

The study included 171 patients (protocol number 119,649/2012-Ethics Committee) with ALL treated at a pediatric treatment center in Belém do Pará, in the Brazilian Amazon. The patients were submitted to the BFM protocol of induction therapy for ALL. Toxicity was assessed based on laboratory tests and adverse events, classified according to the CTC-NCI guide. Genomic ancestry was determined using autosomal informative markers.

RESULTS

The majority of children (94.74%) developed some type of toxicity during treatment, 87.04% of which were severe. Infectious toxicity was the most common, present in 84.8% of cases, 77.24% of which were severe. Amerindian ancestry showed an association with the risk of severe general toxicity and severe infectious toxicity, with a contribution of 35.0% demonstrating a significant increase in risk. In addition, post-induction refractoriness and relapse were also associated with an increased risk of death.

CONCLUSION

This study highlights the influence of Amerindian genomic ancestry on response to therapy and toxicity in children with ALL in the Amazon region. Understanding these associations can contribute to personalizing treatment and improving clinical outcomes.

Investigation of inherited noncoding genetic variation impacting the pharmacogenomics of childhood acute lymphoblastic leukemia treatment

Defining genetic factors impacting chemotherapy failure can help to better predict response and identify drug resistance mechanisms. However, there is limited understanding of the contribution of inherited noncoding genetic variation on inter-individual differences in chemotherapy response in childhood acute lymphoblastic leukemia (ALL). Here we map inherited noncoding variants associated with treatment outcome and/or chemotherapeutic drug resistance to ALL cis-regulatory elements and investigate their gene regulatory potential and target gene connectivity using massively parallel reporter assays and three-dimensional chromatin looping assays, respectively. We identify 54 variants with transcriptional effects and high-confidence gene connectivity. Additionally, functional interrogation of the top variant, rs1247117, reveals changes in chromatin accessibility, PU.1 binding affinity and gene expression, and deletion of the genomic interval containing rs1247117 sensitizes cells to vincristine. Together, these data demonstrate that noncoding regulatory variants associated with diverse pharmacological traits harbor significant effects on allele-specific transcriptional activity and impact sensitivity to antileukemic agents.

A noncoding regulatory variant in IKZF1 increases acute lymphoblastic leukemia risk in Hispanic/Latino children

Hispanic/Latino children have the highest risk of acute lymphoblastic leukemia (ALL) in the US compared to other racial/ethnic groups, yet the basis of this remains incompletely understood. Through genetic fine-mapping analyses, we identified a new independent childhood ALL risk signal near IKZF1 in self-reported Hispanic/Latino individuals, but not in non-Hispanic White individuals, with an effect size of ∼1.44 (95% confidence interval = 1.33-1.55) and a risk allele frequency of ∼18% in Hispanic/Latino populations and <0.5% in European populations. This risk allele was positively associated with Indigenous American ancestry, showed evidence of selection in human history, and was associated with reduced IKZF1 expression. We identified a putative causal variant in a downstream enhancer that is most active in pro-B cells and interacts with the IKZF1 promoter. This variant disrupts IKZF1 autoregulation at this enhancer and results in reduced enhancer activity in B cell progenitors. Our study reveals a genetic basis for the increased ALL risk in Hispanic/Latino children.

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.

A comprehensive analysis of neuroblastoma incidence, survival, and racial and ethnic disparities from 2001 to 2019

BACKGROUND

We characterize the incidence and 5-year survival of children and adolescents with neuroblastoma stratified by demographic and clinical factors based on the comprehensive data from United States Cancer Statistics (USCS) and the National Program of Cancer Registries (NPCR).

METHODS

We analyzed the incidence of neuroblastoma from USCS (2003-2019) and survival data from NPCR (2001-2018) for patients less than 20 years old. Incidence trends were calculated by average annual percent change (AAPC) using joinpoint regression. Differences in relative survival were estimated comparing non-overlapping confidence intervals (CI).

RESULTS

We identified 11,543 primary neuroblastoma cases in USCS. Age-adjusted incidence was 8.3 per million persons [95% CI: 8.2, 8.5], with an AAPC of 0.4% [95% CI: -0.1, 0.9]. Five-year relative survival from the NPCR dataset (n = 10,676) was 79.7% [95% CI: 78.9, 80.5]. Patients aged less than 1 year had the highest 5-year relative survival (92.5%). Five-year relative survival was higher for non-Hispanic White patients (80.7%) or Hispanic patients (80.8%) compared to non-Hispanic Black patients (72.6%).

CONCLUSION

Neuroblastoma incidence was stable during 2003-2019. Differences in relative survival exist by sex, age, race/ethnicity, and stage; patients who were male, older, non-Hispanic Black, or with distant disease had worse survival. Future studies could seek to assess the upstream factors driving disparities in survival, and evaluate interventions to address inequities and improve survival across all groups.

Pharmacogenetics of pediatric acute lymphoblastic leukemia in Uruguay: adverse events related to induction phase drugs

In Uruguay, the pediatric acute lymphoblastic leukemia (ALL) cure rate is 82.2%, similar to those reported in developed countries. However, many patients suffer adverse effects that could be attributed, in part, to genetic variability. This study aims to identify genetic variants related to drugs administered during the induction phase and analyze their contribution to adverse effects, considering individual genetic ancestry. Ten polymorphisms in five genes (ABCB1, CYP3A5, CEP72, ASNS, and GRIA1) related to prednisone, vincristine, and L-asparaginase were genotyped in 200 patients. Ancestry was determined using 45 ancestry informative markers (AIMs). The sample ancestry was 69.2% European, 20.1% Native American, and 10.7% African, but with high heterogeneity. Mucositis, Cushing syndrome, and neurotoxicity were the only adverse effects linked with genetic variants and ancestry. Mucositis was significantly associated with ASNS (rs3832526; 3R/3R vs. 2R carriers; OR: = 6.88 [1.88-25.14], p = 0.004) and CYP3A5 (non-expressors vs. expressors; OR: 4.55 [1.01-20.15], p = 0.049) genes. Regarding Cushing syndrome, patients with the TA genotype (rs1049674, ASNS) had a higher risk of developing Cushing syndrome than those with the TT genotype (OR: 2.60 [1.23-5.51], p = 0.012). Neurotoxicity was significantly associated with ABCB1 (rs9282564; TC vs. TT; OR: 4.25 [1.47-12.29], p = 0.007). Moreover, patients with <20% Native American ancestry had a lower risk of developing neurotoxicity than those with ≥20% (OR: 0.312 [0.120-0.812], p = 0.017). This study shows the importance of knowing individual genetics to improve the efficacy and safety of acute lymphoblastic leukemia.

Evaluating genomic polygenic risk scores for childhood acute lymphoblastic leukemia in Latinos

The utility of polygenic risk score (PRS) models has not been comprehensively evaluated for childhood acute lymphoblastic leukemia (ALL), the most common type of cancer in children. Previous PRS models for ALL were based on significant loci observed in genome-wide association studies (GWASs), even though genomic PRS models have been shown to improve prediction performance for a number of complex diseases. In the United States, Latino (LAT) children have the highest risk of ALL, but the transferability of PRS models to LAT children has not been studied. In this study, we constructed and evaluated genomic PRS models based on either non-Latino White (NLW) GWAS or a multi-ancestry GWAS. We found that the best PRS models performed similarly between held-out NLW and LAT samples (PseudoR2 = 0.086 ± 0.023 in NLW vs. 0.060 ± 0.020 in LAT), and can be improved for LAT if we performed GWAS in LAT-only (PseudoR2 = 0.116 ± 0.026) or multi-ancestry samples (PseudoR2 = 0.131 ± 0.025). However, the best genomic models currently do not have better prediction accuracy than a conventional model using all known ALL-associated loci in the literature (PseudoR2 = 0.166 ± 0.025), which includes loci from GWAS populations that we could not access to train genomic PRS models. Our results suggest that larger and more inclusive GWASs may be needed for genomic PRS to be useful for ALL. Moreover, the comparable performance between populations may suggest a more oligogenic architecture for ALL, where some large effect loci may be shared between populations. Future PRS models that move away from the infinite causal loci assumption may further improve PRS for ALL.

In vitro simulation of the acute lymphoblastic leukemia niche: a critical view on the optimal approximation for drug testing

Acute lymphoblastic leukemia with the worst prognosis is related to minimal residual disease. Minimal residual disease not only depends on the individual peculiarities of leukemic clones but also reflects the protective role of the acute lymphoblastic leukemia microenvironment. In this review, we discuss in detail cell-to-cell interactions in the 2 leukemic niches, more explored bone marrow and less studied extramedullary adipose tissue. A special emphasis is given to multiple ways of interactions of acute lymphoblastic leukemia cells with the bone marrow or extramedullary adipose tissue microenvironment, indicating observed differences in B- and T-cell-derived acute lymphoblastic leukemia behavior. This analysis argued for the usage of coculture systems for drug testing. Starting with a review of available sources and characteristics of acute lymphoblastic leukemia cells, mesenchymal stromal cells, endothelial cells, and adipocytes, we have then made an update of the available 2-dimensional and 3-dimensional systems, which bring together cellular elements, components of the extracellular matrix, or its imitation. We discussed the most complex available 3-dimensional systems like "leukemia-on-a-chip," which include either a prefabricated microfluidics platform or, alternatively, the microarchitecture, designed by using the 3-dimensional bioprinting technologies. From our analysis, it follows that for preclinical antileukemic drug testing, in most cases, intermediately complex in vitro cell systems are optimal, such as a "2.5-dimensional" coculture of acute lymphoblastic leukemia cells with niche cells (mesenchymal stromal cells, endothelial cells) plus matrix components or scaffold-free mesenchymal stromal cell organoids, populated by acute lymphoblastic leukemia cells. Due to emerging evidence for the correlation of obesity and poor prognosis, a coculture of adipocytes with acute lymphoblastic leukemia cells as a drug testing system is gaining shape.

Evaluating Genomic Polygenic Risk Scores for Childhood Acute Lymphoblastic Leukemia in Latinos

The utility of polygenic risk score (PRS) models has not been comprehensively evaluated for childhood acute lymphoblastic leukemia (ALL), the most common type of cancer in children. Previous PRS models for ALL were based on significant loci observed in genome-wide association studies (GWAS), even though genomic PRS models have been shown to improve prediction performance for a number of complex diseases. In the United States, Latino (LAT) children have the highest risk of ALL, but the transferability of PRS models to LAT children has not been studied. In this study we constructed and evaluated genomic PRS models based on either non-Latino white (NLW) GWAS or a multi-ancestry GWAS. We found that the best PRS models performed similarly between held-out NLW and LAT samples (PseudoR 2 = 0.086 ± 0.023 in NLW vs. 0.060 ± 0.020 in LAT), and can be improved for LAT if we performed GWAS in LAT-only (PseudoR 2 = 0.116 ± 0.026) or multi-ancestry samples (PseudoR 2 = 0.131 ± 0.025). However, the best genomic models currently do not have better prediction accuracy than a conventional model using all known ALL-associated loci in the literature (PseudoR 2 = 0.166 ± 0.025), which includes loci from GWAS populations that we could not access to train genomic PRS models. Our results suggest that larger and more inclusive GWAS may be needed for genomic PRS to be useful for ALL. Moreover, the comparable performance between populations may suggest a more oligo-genic architecture for ALL, where some large effect loci may be shared between populations. Future PRS models that move away from the infinite causal loci assumption may further improve PRS for ALL.

Partnering With Patients and Caregivers in Cancer Care: Lessons From Experiences With Transgender, Hispanic, and Pediatric Populations

A cancer diagnosis thrusts patients and caregivers into a foreign world of health care with systems, protocols, and norms that can leave little room for individual needs and circumstances. Quality and efficacious oncology care requires clinicians to partner with patients and caregivers to understand and incorporate their needs, values, and priorities into information sharing, decision making, and care provision. This partnership is necessary for effective patient- and family-centered care and access to individualized and equitable information, treatment, and research participation. Partnering with patients and families also requires oncology clinicians to see that our personal values, preconceived ideas, and established systems exclude certain populations and potentially lead to poorer care for all patients. Furthermore, inequitable access to participation in research and clinical trials can contribute to an unequal burden of cancer morbidity and mortality. Leveraging the expertise of the authorship team with transgender, Hispanic, and pediatric populations, this chapter provides insights and suggestions for oncology care that are applicable across patient populations to mitigate stigma and discrimination and improve the quality of care for all patients.

Access to Chimeric Antigen Receptor T Cell Clinical Trials in Underrepresented Populations: A Multicenter Cohort Study of Pediatric and Young Adult Acute Lymphobastic Leukemia Patients

Chimeric antigen receptor T cell (CAR-T) therapy is a promising approach to improve survival for children and adults with relapsed/refractory (r/r) B cell acute lymphoblastic leukemia (B-ALL), but these clinical trials might not be equally accessible to patients of low socioeconomic status (SES) or to patients from racial or ethnic minority groups. We sought to describe the sociodemographic characteristics of pediatric and adolescent and young adult (AYA) patients enrolled in CAR-T clinical trials and to compare these characteristics to those of other patients with r/r B-ALL. We conducted a multicenter retrospective cohort study at 5 pediatric consortium sites to compare the sociodemographic characteristics of patients treated and enrolled in CAR-T trials at their home institution, other patients with r/r B-ALL treated at these sites, and patients referred from an external hospital for CAR-T trials. The patients were age 0 to 27 years with r/r B-ALL treated at 1 of the consortium sites between 2012 and 2018. Clinical and demographic data were collected from the electronic health record. We calculated distance from home to treating institution and assigned SES scores based on census tract. Among the 337 patients treated for r/r B-ALL, 112 were referred from an external hospital to a consortium site and enrolled in a CAR-T trial and 225 were treated primarily at a consortium site, with 34% enrolled in a CAR-T trial. Patients treated primarily at a consortium site had similar characteristics regardless of trial enrollment. Lower proportions of Hispanic patients (37% versus 56%; P = .03), patients whose preferred language was Spanish (8% versus 22%; P = .006), and publicly insured patients (38% versus 65%; P = .001) were referred from an external hospital than were treated primarily at a consortium site and enrolled in a CAR-T trial. Patients who are Hispanic, Spanish-speaking, or publicly insured are underrepresented in referrals from external hospitals to CAR-T centers. External provider implicit bias also may influence referral of these patients. Establishing partnerships between CAR-T centers and external hospital sites may improve provider familiarity, patient referral, and patient access to CAR-T clinical trials.

Racial and ethnic disparities in childhood and young adult acute lymphocytic leukaemia: secondary analyses of eight Children's Oncology Group cohort trials

BACKGROUND

Previous studies have identified racial and ethnic disparities in childhood acute lymphocytic leukaemia survival. We aimed to establish whether disparities persist in contemporaneous cohorts and, if present, are attributable to differences in leukaemia biology or insurance status.

METHODS

Patients with newly diagnosed acute lymphocytic leukaemia in inpatient and outpatient centres in the USA, Canada, Australia, and New Zealand, aged 0-30 years, who had race or ethnicity data available, enrolled on eight completed Children's Oncology Group trials (NCT00103285, NCT00075725, NCT00408005, NCT01190930, NCT02883049, NCT02112916, NCT02828358, and NCT00557193) were included in this secondary analysis. Race and ethnicity were categorised as non-Hispanic White, Hispanic, non-Hispanic Black, non-Hispanic Asian, and non-Hispanic other. Event-free survival and overall survival were compared across race and ethnicity groups. The relative contribution of clinical and biological disease prognosticators and insurance status was examined through multivariable regression models, both among the entire cohort and among those with B-cell lineage versus T-cell lineage disease.

FINDINGS

Between Jan 1, 2004, and Dec 31, 2019, 24 979 eligible children, adolescents, and young adults with acute lymphocytic leukaemia were enrolled, of which 21 152 had race or ethnicity data available. 11 849 (56·0%) were male and 9303 (44·0%) were female. Non-Hispanic White patients comprised the largest racial or ethnic group (13 872 [65·6%]), followed by Hispanic patients (4354 [20·6%]), non-Hispanic Black patients (1517 [7·2%]), non-Hispanic Asian (n=1071 [5·1%]), and non-Hispanic other (n=338 [1·6%]). 5-year event-free survival was 87·4% (95% CI 86·7-88·0%) among non-Hispanic White patients compared with 82·8% (81·4-84·1%; hazard ratio [HR] 1·37, 95% CI 1·26-1·49; p<0·0001) among Hispanic patients and 81·8% (79·3-84·0; HR 1·45, 1·28-1·65; p<0·0001) among non-Hispanic Black patients. Non-hispanic Asian patients had a 5-year event-free survival of 88·1% (95% CI 85·5-90·3%) and non-Hispanic other patients had a survival of 82·8% (76·4-87·6%). Inferior event-free survival among Hispanic patients was substantially attenuated by disease prognosticators and insurance status (HR decreased from 1·37 [1·26-1·49; p<0·0001] to 1·11 [1·00-1·22; p=0·045]). The increased risk among non-Hispanic Black patients was minimally attenuated (HR 1·45 [1·28-1·65; p<0·0001] to 1·32 [1·14-1·52; p<0·0001]). 5-year overall survival was 93·6% (91·5-95·1%) in non-Hispanic Asian patients, 93·3% (92·8-93·7%) in non-Hispanic White patients, 89·9% (88·7-90·9%) in Hispanic, 89·7% (87·6-91·4%) in non-Hispanic Black patients, 88·9% (83·2-92·7%) in non-Hispanic other patients. Disparities in overall survival were wider than event-free survival (eg, among non-Hispanic other patients, the HR for event-free survival was 1·43 [1·10-1·85] compared with 1·74 [1·27-2·40] for overall survival). Disparities were restricted to patients with B-cell acute lymphocytic leukaemia, no differences in event-free survival or overall survival were seen in the T-cell acute lymphocytic leukaemia group.

INTERPRETATION

Substantial disparities in outcome for B-cell acute lymphocytic leukaemia persist by race and ethnicity, but are not observed in T-cell acute lymphocytic leukaemia. Future studies of relapsed patients, access to and quality of care, and other potential aspects of structural racism are warranted to inform interventions aimed at dismantling racial and ethnic disparities.

FUNDING

National Cancer Institute and St Baldrick's Foundation.

Measuring disparities in event-free survival among children with acute lymphoblastic leukemia in an academic institute in Oklahoma, 2005-2019

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common type of childhood cancer. While there have been successes in the treatment of leukemia, less information is available on reasons for disparities in event-free survival (EFS) among underserved populations.

METHODS

We partnered with a children's hospital at an academic institution to abstract data from the institution's cancer registry, the state cancer registry, and electronic medical records on cancer diagnosis, treatment, and outcomes for children with ALL (n = 275) diagnosed from 2005 to 2019 prior to age 20. We evaluated the relation between 1) race/ethnicity, 2) distance to the children's hospital, and 3) area deprivation with EFS, defined as time from diagnosis to relapse, death, or the end of the study period. We evaluated differences in EFS using Kaplan-Meier analysis with the log-rank test. We used the Cox Proportional Hazards Model for multivariable survival analyses.

RESULTS

Most children were diagnosed with ALL under five years of age (45%) and with Pre-B ALL (87%). Twelve percent of children experienced a relapse and 5% died during induction or remission. EFS at 5 years was 82%. Non-Hispanic (NH) Black children had worse, though imprecise, EFS compared to NH White children (Adjusted Hazard Ratio: 2.07, 95% CI: 0.80, 5.38). Children residing in areas with higher deprivation had a higher adjusted hazard of poor outcomes compared to the least deprived areas, though estimates were imprecise (2nd quartile HR: 1.51, 3rd quartile: 1.85, 4th quartile: 1.62). We observed no association between distance to the children's hospital and EFS.

CONCLUSION

We observed poorer EFS for NH Black children and children residing in areas with high deprivation, though the estimates were not statistically significant. Our next steps include further evaluating socioeconomic factors in both rural and urban children to identify disparities in outcomes for children with ALL and other childhood cancers.

Survival disparities for childhood cancers exist when defined by race/ethnicity and sex

BACKGROUND

There are documented racial/ethnic and sex differences in pediatric cancer survival; however, it is unknown whether pediatric cancer survival disparities exist when race/ethnicity and sex are considered jointly.

METHODS

Using SEER data (2000-2017), we estimated survival differences by race/ethnicity within sexes and by sex within race/ethnicity (White, Black, Hispanic, and Asian/Pacific Islander [API]) for 17 cancers in children aged (0-19 years). Kaplan-Meier curves (Log-Rank p-values) were assessed. Cox regression was used to estimate hazards ratios (HRs) and 95 % confidence intervals (95 % CIs) between race/ethnicity/sex and cancer.

RESULTS

We included 51,759 cases (53.6 % male, 51.9 % White). There were statistically significant differences in 18-year survival by race/ethnicity-sex for 12/17 cancers. Within sexes, minorities had an increased risk of death compared to Whites for various cancers including acute lymphoblastic leukemia (ALL) (females: HispanicHR: 1.78, 95 % CI: 1.52, 2.10; BlackHR: 1.70, 95 % CI: 1.29, 2.24; APIHR: 1.42, 95 % CI: 1.07-1.89; males ALL: HispanicHR: 1.58, 95 % CI: 1.39,1.79; BlackHR: 1.57, 95 % CI: 1.26,1,95; API-HR: 1.39, 95 % CI: 1.11, 1.75) and astrocytoma (females: HispanicHR: 1.49, 95 % CI: 1.19, 1.85; BlackHR: 1.67, 95 % CI: 1.29, 2.17; API-HR: 1.51, 95 % CI: 1.05, 2.15; males: HispanicHR:1.27, 95 % CI: 1.04, 1.56; BlackHR: 1.69, 95 % CI: 1.32, 2.17; API-HR: 1.92, 95 % CI: 1.43, 2.58). Sex differences in survival within racial/ethnic groups were observed for White (ALL, osteosarcoma), Hispanic (medulloblastoma), and API (Primitive Neuro-Ectodermal Tumor [PNET]) children.

CONCLUSIONS

There are disparities in survival by both race/ethnicity and sex highlighting the societal and biologic influences these features have on survival in children with cancer.

Association of race/ethnicity with innate immune tumor microenvironment of children with B-acute lymphoblastic leukemia

BACKGROUND

Black and Hispanic children with B-acute lymphoblastic leukemia (B-ALL) experience worse outcomes compared with their non-Hispanic white (NHW) counterparts. Immune-based approaches have begun to transform the therapeutic landscape in children with B-ALL. Recent studies identified several alterations in both innate and adaptive immune cells in children with B-ALL that may impact disease risk and outcome. However, the impact of racial/ethnic background on immune microenvironment is less studied, as children of minorities background have to date been severely under-represented in such studies.

METHODS

We performed high-dimensional analysis of bone marrow from 85 children with newly diagnosed B-ALL (Hispanic=29, black=18, NHW=38) using mass cytometry with 40 and 38-marker panels.

RESULTS

Race/ethnicity-associated differences were most prominent in the innate immune compartment. Hispanic patients had significantly increased proportion of distinct mature CD57 +T-bet+DR+ NK cells compared with other cohorts. These differences were most apparent within standard risk (SR) patients with Hispanic SR patients having greater numbers of CD57 +NK cells compared with other cohorts (43% vs 26% p=0.0049). Hispanic and Black children also had distinct alterations in myeloid cells, with a significant increase in a population of non-classical activated HLA-DR +CD16+myeloid cells, previously implicated in disease progression, compared with NHW counterparts. Racial background also correlated with altered expression of inhibitory checkpoint PD-L1 on myeloid cells.

CONCLUSION

There are surprisingly substantial race/ethnicity-based differences in innate immune cells of children with newly diagnosed B-ALL. These differences urge the need to enhance accrual of children from minorities background in immunetherapy trials and may impact their outcome following such therapy.

Factors that contribute to disparities in time to acute leukemia diagnosis in young people: an in depth qualitative interview study

BACKGROUND

Racial and ethnic disparities in outcomes for Black and Hispanic children with acute leukemia have been well documented, however little is known about the determinants of diagnostic delays in pediatric leukemia in the United States. The primary objective of this study is to identify factors contributing to delays preceding a pediatric leukemia diagnosis.

METHODS

This qualitative study utilized in-depth semi-structured interviews. Parents and/or patients within two years of receiving a new acute leukemia diagnosis were asked to reflect upon their family's experiences preceding the patient's diagnosis. Subjects were purposively sampled for maximum variation in race, ethnicity, income, and language. Interviews were analyzed using inductive theory-building and the constant comparative method to understand the process of diagnosis. Chart review was conducted to complement qualitative data.

RESULTS

Thirty-two interviews were conducted with a diverse population of English and Spanish speaking participants from two tertiary care pediatric cancer centers. Parents reported feeling frustrated when their intuition conflicted with providers' management decisions. Many felt laboratory testing was not performed soon enough. Additional contributors to delays included misattribution of vague symptoms to more common diagnoses, difficulties in obtaining appointments, and financial disincentives to seek urgent or emergent care. Reports of difficulty obtaining timely appointments and financial concerns were disproportionately raised among low-income Black and Hispanic participants. Comparatively, parents with prior healthcare experiences felt better able to navigate the system and advocate for additional testing at symptom onset.

CONCLUSIONS

While there are disease-related factors contributing to delays in diagnosis, it is important to recognize there are multiple non-disease-related factors that also contribute to delays. Evidence-based approaches to reduce outcome disparities in pediatric cancer likely need to start in the primary care setting where timeliness of diagnosis can be addressed.

Association of Genetic Ancestry With the Molecular Subtypes and Prognosis of Childhood Acute Lymphoblastic Leukemia

IMPORTANCE

Racial and ethnic disparities persist in the incidence and treatment outcomes of childhood acute lymphoblastic leukemia (ALL). However, there is a paucity of data describing the genetic basis of these disparities, especially in association with modern ALL molecular taxonomy and in the context of contemporary treatment regimens.

OBJECTIVE

To evaluate the association of genetic ancestry with childhood ALL molecular subtypes and outcomes of modern ALL therapy.

DESIGN, SETTING, AND PARTICIPANTS

This multinational, multicenter genetic association study was conducted from March 1, 2000, to November 20, 2020, among 2428 children and adolescents with ALL enrolled in frontline trials from the United States, South East Asia (Singapore and Malaysia), and Latin America (Guatemala), representing diverse populations of European, African, Native American, East Asian, and South Asian descent. Statistical analysis was conducted from February 3, 2020, to April 19, 2021.

MAIN OUTCOMES AND MEASURES

Molecular subtypes of ALL and genetic ancestry were comprehensively characterized by performing RNA sequencing. Associations of genetic ancestries with ALL molecular subtypes and treatment outcomes were then evaluated.

RESULTS

Among the participants in the study, 1340 of 2318 (57.8%) were male, and the mean (SD) age was 7.8 (5.3) years. Of 21 ALL subtypes identified, 8 were associated with ancestry. East Asian ancestry was positively associated with the frequency of somatic DUX4 (odds ratio [OR], 1.30 [95% CI, 1.16-1.45]; P < .001) and ZNF384 (OR, 1.40 [95% CI, 1.18-1.66]; P < .001) gene rearrangements and negatively associated with BCR-ABL1-like ALL (OR, 0.79 [95% CI, 0.66-0.92]; P = .002) and T-cell ALL (OR, 0.80 [95% CI, 0.71-0.90]; P < .001). By contrast, occurrence of CRLF2 rearrangements was associated with Native American ancestry (OR, 1.48 [95% CI, 1.29-1.69]; P < .001). When the percentage of Native American ancestry increased, ETV6-RUNX1 fusion became less frequent (OR, 0.80 [95% CI, 0.70-0.91]; P < .001), with the opposite trend observed for ETV6-RUNX1-like ALL. There was a marked preponderance of T-cell ALL in children of African descent compared with those with a high percentage of Native American ancestry (African: OR, 1.22 [95% CI, 1.07-1.37]; P = .003; Native American: OR, 0.53 [95% CI, 0.40-0.67]; P < .001). African ancestry was also positively associated with the prevalence of TCF3-PBX1 (OR, 1.49 [95% CI, 1.25-1.76]; P < .001) and negatively associated with DUX4 rearrangements (OR, 0.70 [95% CI, 0.48-0.93]; P = .01) and hyperdiploidy (OR, 0.77 [95% CI, 0.68-0.86]; P < .001). African and Native American ancestries as continuous variables were both associated with poorer event-free survival (for every 25% increase in ancestry: hazard ratio [HR], 1.2; 95% CI, 1.1-1.4; P = .001 for African ancestry; HR, 1.3; 95% CI, 1.0-1.6; P = .04 for Native American ancestry) and overall survival (for every 25% increase in ancestry: HR, 1.2; 95% CI, 1.1-1.5; P = .01 for African ancestry; HR, 1.4; 95% CI, 1.0-1.8; P = .03 for Native American ancestry). Even after adjusting for biological subtypes and clinical features, Native American and African ancestries remained associated with poor prognosis.

CONCLUSIONS AND RELEVANCE

This study suggests that ALL molecular subtypes and prognosis are associated with genetic ancestry, potentially pointing to a genetic basis for some of the racial and ethnic disparities in ALL. Therefore, molecular subtype-driven treatment individualization is needed to help address racial and ethnic gaps in outcomes.

Prognostic value of CD20 antigen mediated immune checkpoint inhibition in patients with acute or chronic lymphocytic leukemia: A protocol for systematic review

BACKGROUND

The addition of rituximab to standard chemotherapy has been shown to improve response rates in patients with acute or chronic lymphocytic leukemia. However, the prognostic factors associated with progression-free survival in rituximab treated patients with lymphocytic leukemias remains unclear. We will perform a comprehensive systematic review and meta-analysis on available data on prognostic factors associated with the clinical outcomes of patients with acute and chronic lymphocytic leukemia.

METHODS AND ANALYSIS

This protocol for a systematic review and meta-analysis of prognostic factors has been prepared following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines. Electronic databases will be searched using keywords related to the objectives of this review. This systematic review and meta-analysis will include published randomized clinical trials, observational, prospective, and retrospective comparative cohorts. Two reviewers (ZAM and SAM) will independently screen studies, with a third reviewer consulted in cases of disagreements using a defined inclusion and exclusion criteria. Data items will be extracted using a predefined data extraction sheet. Moreover, the risk of bias and the quality of evidence were independently assessed using the quality in prognostic studies tool (QUIPS). The I2 and chi squared statistical tests will be used to analyze statistical heterogeneity across studies. An I2 values of > 50% will be considered substantial. All data analysis will be performed using STATA 16.0 (StataCorp LP, TX, USA). The outcomes examined will be progression-free and overall survival.

ETHICS AND DISSEMINATION

No ethical approval will be required and the findings of this meta-analysis will be published in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

International prospective Register of Systematic Reviews (PROSERO) number: CRD42021218997.

Cancer statistics for the US Hispanic/Latino population, 2021

The Hispanic/Latino population is the second largest racial/ethnic group in the continental United States and Hawaii, accounting for 18% (60.6 million) of the total population. An additional 3 million Hispanic Americans live in Puerto Rico. Every 3 years, the American Cancer Society reports on cancer occurrence, risk factors, and screening for Hispanic individuals in the United States using the most recent population-based data. An estimated 176,600 new cancer cases and 46,500 cancer deaths will occur among Hispanic individuals in the continental United States and Hawaii in 2021. Compared to non-Hispanic Whites (NHWs), Hispanic men and women had 25%-30% lower incidence (2014-2018) and mortality (2015-2019) rates for all cancers combined and lower rates for the most common cancers, although this gap is diminishing. For example, the colorectal cancer (CRC) incidence rate ratio for Hispanic compared with NHW individuals narrowed from 0.75 (95% CI, 0.73-0.78) in 1995 to 0.91 (95% CI, 0.89-0.93) in 2018, reflecting delayed declines in CRC rates among Hispanic individuals in part because of slower uptake of screening. In contrast, Hispanic individuals have higher rates of infection-related cancers, including approximately two-fold higher incidence of liver and stomach cancer. Cervical cancer incidence is 32% higher among Hispanic women in the continental US and Hawaii and 78% higher among women in Puerto Rico compared to NHW women, yet is largely preventable through screening. Less access to care may be similarly reflected in the low prevalence of localized-stage breast cancer among Hispanic women, 59% versus 67% among NHW women. Evidence-based strategies for decreasing the cancer burden among the Hispanic population include the use of culturally appropriate lay health advisors and patient navigators and targeted, community-based intervention programs to facilitate access to screening and promote healthy behaviors. In addition, the impact of the COVID-19 pandemic on cancer trends and disparities in the Hispanic population should be closely monitored.

Racial/Ethnic Disparities in Childhood Cancer Survival in the United States

BACKGROUND

Non-white patients with childhood cancer have worse survival than Non-Hispanic (NH) White patients for many childhood cancers in the United States. We examined the contribution of socioeconomic status (SES) and health insurance on racial/ethnic disparities in childhood cancer survival.

METHODS

We used the National Cancer Database to identify NH White, NH Black, Hispanic, and children of other race/ethnicities (<18 years) diagnosed with cancer between 2004 and 2015. SES was measured by the area-level social deprivation index (SDI) at patient residence and categorized into tertiles. Health insurance coverage at diagnosis was categorized as private, Medicaid, and uninsured. Cox proportional hazard models were used to compare survival by race/ethnicity. We examined the contribution of health insurance and SES by sequentially adjusting for demographic and clinical characteristics (age group, sex, region, metropolitan statistical area, year of diagnosis, and number of conditions other than cancer), health insurance, and SDI.

RESULTS

Compared with NH Whites, NH Blacks and Hispanics had worse survival for all cancers combined, leukemias and lymphomas, brain tumors, and solid tumors (all P < 0.05). Survival differences were attenuated after adjusting for health insurance and SDI separately; and further attenuated after adjusting for insurance and SDI together.

CONCLUSIONS

Both SES and health insurance contributed to racial/ethnic disparities in childhood cancer survival.

IMPACT

Improving health insurance coverage and access to care for children, especially those with low SES, may mitigate racial/ethnic survival disparities.

Race as a factor in donor selection and survival of children with hematologic malignancies undergoing hematopoietic stem cell transplant in Florida

BACKGROUND

Previous studies have explored posthematopoietic cell transplant (HCT) outcomes by race in adults; however, pediatric data addressing this topic are scarce.

PROCEDURE

This retrospective registry study included 238 White (W) and 57 Black (B) children with hematologic malignancies (HM) receiving first allogeneic HCT between 2010 and 2019 at one of the five Florida pediatric HCT centers.

RESULTS

We found no differences between W and B children in transplant characteristics, other than donor type. There was a significant difference in use of human leukocyte antigen (HLA)-mismatched donors (HLA-MMD) (53% W, 71% B, p = .01). When comparing HLA-MMD use to fully HLA-matched donors, B had relative risk (RR) of 1.47 (95% CI 0.7-3) of receiving a mismatched unrelated donor (MMUD), RR of 2.34 (95% CI 1.2-4.4) of receiving a mismatched related donor (MMRD), and RR of 1.9 (95% CI 0.99-3.6) of receiving a mismatched cord blood donor (MMCBD) HCT, respectively. There was no significant difference in the incidence of aGVHD (48% W, 35% B), p = .1, or cGVHD (19% W, 28% B, p = .1), or primary cause of death. Overall 24-month survival was 61% (95% CI 55%-68%) for W, and 60% (95% CI 48-75) for B children, log-rank p = .7. While HLA matching improved survival in W children, the number of B children receiving HLA-matched HCT was too small to identify the impact of HLA matching on survival.

CONCLUSIONS

In this contemporary cohort of children with HM, we found that B children were more likely to receive HLA-MMD transplants, but this did not adversely affect survival or GVHD rates.

Residence in a Hispanic Enclave Is Associated with Inferior Overall Survival among Children with Acute Lymphoblastic Leukemia

Hispanic children with acute lymphoblastic leukemia (ALL) experience poorer overall survival (OS) than non-Hispanic White children; however, few studies have investigated the social determinants of this disparity. In Texas, many Hispanic individuals reside in ethnic enclaves-areas with high concentrations of immigrants, ethnic-specific businesses, and language isolation, which are often socioeconomically deprived. We determined whether enclave residence was associated with ALL survival, overall and among Hispanic children. We computed Hispanic enclave index scores for Texas census tracts, and classified children (N = 4083) as residing in enclaves if their residential tracts scored in the highest statewide quintile. We used Cox regression to evaluate the association between enclave residence and OS. Five-year OS was 78.6% for children in enclaves, and 77.8% for Hispanic children in enclaves, both significantly lower (p < 0.05) than the 85.8% observed among children not in enclaves. Children in enclaves had increased risk of death (hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.01-1.49) after adjustment for sex, age at diagnosis, year of diagnosis, metropolitan residence and neighborhood socioeconomic deprivation and after further adjustment for child race/ethnicity (HR 1.19, 95% CI 0.97-1.45). We observed increased risk of death when analyses were restricted to Hispanic children specifically (HR 1.30, 95% CI 1.03-1.65). Observations suggest that children with ALL residing in Hispanic enclaves experience inferior OS.

Genetic Alterations in Childhood Acute Lymphoblastic Leukemia: Interactions with Clinical Features and Treatment Response

Acute lymphoblastic leukemia (ALL) is the most common cancer among children. This aggressive cancer comprises multiple molecular subtypes, each harboring a distinct constellation of somatic, and to a lesser extent, inherited genetic alterations. With recent advances in genomic analyses such as next-generation sequencing techniques, we can now clearly identify >20 different genetic subtypes in ALL. Clinically, identifying these genetic subtypes will better refine risk stratification and determine the optimal intensity of therapy for each patient. Underpinning each genetic subtype are unique clinical and therapeutic characteristics, such as age and presenting white blood cell (WBC) count. More importantly, within each genetic subtype, there is much less variability in treatment response and survival outcomes compared with current risk factors such as National Cancer Institute (NCI) criteria. We review how this new taxonomy of genetic subtypes in childhood ALL interacts with clinical risk factors used widely, i.e., age, presenting WBC, IKZF1del, treatment response, and outcomes.

Factors associated with 5- and 10-year survival among a recent cohort of childhood cancer survivors (France, 2000-2015)

BACKGROUND

Childhood cancer survival currently exceeds 80 % five years after diagnosis in high-income countries. In this study, we aimed to describe long-term trends and to investigate socioeconomic and spatial disparities in childhood cancer survival.

METHODS

The study included 28,073 cases recorded in the French National Registry of Childhood Cancers from 2000 to 2015. Contextual census data (deprivation indices, population density, spatial accessibility to general practitioners) were allocated to each case based on the residence at diagnosis. Overall survival (OS) and conditional 10-year OS for 5-year survivors were estimated for all cancers combined and by diagnostic group and subgroup. Comparisons were conducted by sex, age at diagnosis, period of diagnosis, and contextual indicators. Hazard ratios for death were estimated using Cox models.

RESULTS

All cancers combined, the OS reached 82.8 % [95 % CI: 82.4-83.3] at 5 years and 80.8 % [95 % CI: 80.3-81.3] at 10 years. Conditional 10-year OS of 5-year survivors reached 97.5 % [95 % CI: 97.3-97.7] and was higher than 95 % for all subgroups except osteosarcomas and most subgroups of the central nervous system. In addition to disparities by sex, age at diagnosis, and period of diagnosis, we observed a slight decrease in survival for cases living in the most deprived areas at diagnosis, not consistent across diagnostic groups.

CONCLUSION

Our results confirm the high 5-year survival for childhood cancer and show an excellent 10-year conditional survival of 5-year survivors. Additional individual data are needed to clarify the factors underlying the slight decrease in childhood cancer survival observed in the most deprived areas.

Racial/ethnic, socioeconomic, and geographic survival disparities in adolescents and young adults with primary central nervous system tumors

BACKGROUND

Disparities in survival by race/ethnicity, socioeconomic status (SES), and geography in adolescent and young adult (AYA) patients with central nervous system (CNS) tumors have not been well studied.

PROCEDURE

A retrospective cohort study utilizing the Surveillance, Epidemiology, and End Results (SEER) database was conducted for AYA patients diagnosed with primary CNS tumors. Adjusted hazard ratios (aHR) were calculated using a multivariate Cox proportional hazard model to evaluate the association between race/ethnicity, SES, rurality, and hazard of death.

RESULTS

All minority groups showed an increased hazard of death with greatest disparities in the high-grade glioma cohort. Lower SES was associated with an increased hazard of death in non-Hispanic White (NHW) patients (aHR 1.12; 95% confidence interval [CI] 1.01-1.24), non-Hispanic Black (NHB) patients (aHR 1.34; 95% CI 1.00-1.80), and patients aged 25-29 years (aHR 1.29; 95% CI 1.07-1.55). Mediation analysis showed an indirect effect of SES on the effect of race/ethnicity on the hazard of death only among NHB patients, with SES accounting for 33.7% of the association between NHB and hazard of death. Rurality was associated with an increased hazard of death for patients in the lowest SES tertile (aHR 1.31; 95% CI 1.08-1.59) and NHW patients (aHR 1.20; 95% CI 1.08-1.34).

CONCLUSIONS

Patients identified as a racial/ethnic minority, patients with a lower SES, and patients residing in rural areas had an increased hazard of death. Further studies are needed to understand and address the biological, psychosocial, societal, and economic factors that impact AYA neuro-oncology patients at highest risk of experiencing poorer outcomes.

CRLF2 and IKZF1 abnormalities in Mexican children with acute lymphoblastic leukemia and recurrent gene fusions: exploring surrogate markers of signaling pathways

The gene fusions BCR-ABL1, TCF3-PBX1, and ETV6-RUNX1 are recurrent in B-cell acute lymphoblastic leukemia (B-ALL) and are found with low frequency in coexistence with CRLF2 (cytokine receptor-like factor 2) rearrangements and overexpression. There is limited information regarding the CRLF2 abnormalities and dominant-negative IKZF1 isoforms associated with surrogate markers of Jak2, ABL, and Ras signaling pathways. To assess this, we evaluated 24 Mexican children with B-ALL positive for recurrent gene fusions at diagnosis. We found CRLF2 rearrangements and/or overexpression, dominant-negative IKZF1 isoforms, and surrogate phosphorylated markers of signaling pathways coexisting with recurrent gene fusions. All the BCR-ABL1 patients expressed CRLF2 and were positive for pCrkl (ABL); most of them were also positive for pStat5 (Jak2/Stat5) and negative for pErk (Ras). TCF3-PBX1 patients with CRLF2 abnormalities were positive for pStat5, most of them were also positive for pCrkl, and two patients were also positive for pErk. One patient with ETV6-RUNX1 and intracellular CRLF2 protein expressed pCrkl. In some cases, the activated signaling pathways were reverted in vitro by specific inhibitors. We further analyzed a TCF3-PBX1 patient at relapse, identifying a clone with the recurrent gene fusion, P2RY8-CRLF2, rearrangement, and phosphorylation of the three surrogate markers that we studied. These results agree with the previous reports regarding resistance to treatment observed in patients with recurrent gene fusions and coexisting CRLF2 gene abnormalities. A marker phosphorylation signature was identified in BCR-ABL1 and TCF3-PBX1 patients. To obtain useful information for the assessment of treatment in B-ALL patients with recurrent gene fusions, we suggest that they should be evaluated at diagnosis for CRLF2 gene abnormalities and dominant-negative IKZF1 isoforms, in addition to the analyses of activation and inhibition of signaling pathways.

Disparities in Pediatric Oncology: The 21st Century Opportunity to Improve Outcomes for Children and Adolescents With Cancer

Adult cancer disparities have been documented for decades and continue to persist despite clinical advancements in cancer prevention, detection, and treatment. Pediatric cancer survival has improved significantly in the United States for the past 5 decades to over 80%; however, disparate outcomes among children and adolescents with cancer still affect many populations in the United States and globally, including racial and ethnic minorities, populations with low socioeconomic status, and residents of underserved areas. To achieve equitable outcomes for all children and adolescents with cancer, it is imperative that concerted multilevel approaches be carried out to understand and address health disparities and to ensure access to high-quality cancer care. Addressing social determinants of health, such as removing barriers to health care access and ensuring access to social supports, can reduce pediatric cancer disparities. Nevertheless, public health policy, health system interventions, and innovative delivery of evidence-based services are critically needed. Partnerships among patients, caregivers, and health care providers, and among health care, academic, and governmental institutions, have a pivotal role in reducing cancer disparities and improving outcomes in the 21st century.

Etiology of Acute Leukemia: A Review

Simple Summary

Acute leukemias are some of the most common cancers affecting all age groups. Despite a significant improvement made in the treatment of acute leukemias, their cause remains unknown. A number of genetic and environmental factors for the development of acute leukemias have been proposed, but none have been proven. Undoubtedly, genetics have a major role in the development of these diseases. The effects of a variety of environmental factors, occupations and hobbies have been explored. A recent “two-hit” theory” for the development of acute lymphoblastic leukemia has been proposed. This combines genetic factors and exposure to infections for the development of this disease. Several genetic factors are suggested. Most recently, for the infection portion, exposure to a virus containing Aspergillus Flavus has been proposed. This review summarizes what is currently known about the factors that are proposed for the development of acute leukemias.

Abstract

Acute leukemias constitute some of the most common malignant disorders. Despite significant progress made in the treatment of these disorders, their etiology remains unknown. A large and diverse group of genetic and environmental variables have been proposed. The role of a variety of factors, including pre-existing and acquired genetic mutations, exposure to radiation and various chemicals during preconception, pregnancy and throughout life, have been explored. The effects of inherited genetic variations and disorders, pre-existing diseases, infectious agents, hobbies, occupations, prior treatments, and a host of other factors have been proposed, but none is universally applicable to all cases. Variation in the incidence and prognosis based on the age, sex, race, type of the disease, geographic area of residence and other factors are intriguing but remain unexplained. Advances in genomic profiling, including genome-wide gene expression, DNA copy number and single nucleotide polymorphism (SNP) genotype, may shed some light on the role of genetics in these disparities. Separate two-hit hypotheses for the development of acute myeloblastic and lymphoblastic leukemia have been proposed. The latter combines genetics and infection factors resulting in leukemogenesis. A number of pre- and post-natal environmental conditions and exposure to infections, including a mycovirus infected Aspergillus flavus, have been suggested. The exact nature, timing, sequence of the events and mechanisms resulting in the occurrence of leukemia requires further investigations. This review summarizes some of the above factors in acute lymphoblastic and myeloblastic leukemias and the direction for future research on the etiology of these disorders.

Are outcomes for childhood leukaemia in Australia influenced by geographical remoteness and Indigenous race?

BACKGROUND

Presenting features, biology and outcome for childhood leukaemia are known to vary by ethnic origin, geographic location and socioeconomic group. This study aimed to compare presentation patterns, follow-up and clinical outcomes in Indigenous and non-Indigenous children with acute leukaemia in Australia, and to assess the impact of remoteness and area-based socioeconomic disadvantage on outcome.

METHODS

A retrospective review of children aged between 1 day and 18 years who were diagnosed with acute leukaemia in South Australia (SA), Northern Territory (NT) and Western Australia (WA) between 2009 and 2018 was performed. Data were collected from children treated at the Women's and Children's Hospital, Adelaide and Perth Children's Hospital.

RESULTS

Analysis of 455 children treated for acute leukaemia showed that children from remote/very remote localities had inferior overall survival (p = .004). Five-year overall survival was 91.7% (95% CI: 87.9-94.3%) for children with acute lymphoblastic leukaemia (ALL) and 69.8% (56.7-79.5%) for acute myeloid leukaemia (AML). A larger proportion of Indigenous children from SA/NT were diagnosed with AML compared to non-Indigenous children (60.0% vs. 14.4%, p = .001). Indigenous children were less likely to be enrolled on clinical trials (34.5% vs. 53.1%, p = .03) and more likely to be lost to follow-up (26.1% vs. 9.2%, p = .009).

CONCLUSION

Geographic remoteness of residence is associated with inferior overall survival for Australian children with leukaemia. Indigenous children with acute leukaemia suffer from disparities in outcomes. These findings provide evidence to guide national policy in supporting appropriate resource allocation to overcome the challenges faced by children within these groups.

Associations between race and survival in pediatric patients with diffuse large B-cell lymphoma

BACKGROUND

The purpose of this study was to examine the factors associated with disparities in overall survival (OS) by race in pediatric diffuse large B-cell lymphoma (DLBCL) patients.

METHODS

We evaluated clinical features and survival among patients ≤21 years of age diagnosed with stage I-IV DLBCL from 2004 to 2014 from the National Cancer Database (NCDB) using a multivariable Cox proportional hazards model.

RESULTS

Among 1386 pediatric patients with DLBCL, 1023 patients met eligibility criteria. In unadjusted analysis, Black patients had a significantly higher overall death rate than White patients (HRBlack vs. White 1.51; 95% CI: 1.02-2.23, p = 0.041). The survival disparity did not remain significant in adjusted analysis, though controlling for covariates had little effect on the magnitude of the disparity (HR 1.46; 95% CI 0.93-2.31, p = 0.103). In adjusted models, presence of B symptoms, receipt of chemotherapy, stage of disease, and Other insurance were significantly associated with OS. Specifically, patients with B symptoms and those with Other insurance were more likely to die than those without B symptoms or private insurance, respectively (HR 1.75; 95% CI 1.22-2.50, p = 0.002) and (HR 2.56; 95% CI, 1.39-4.73, p = 0.0027), patients who did not receive chemotherapy were three times more likely to die than those who received chemotherapy (HR 3.10; CI 1.80-5.35, p < 0.001), and patients who presented with earlier stage disease were less likely to die from their disease than those with stage IV disease (stages I-III HR 0.34, CI 0.18-0.64, p < 0.001; HR 0.50, CI 0.30-0.82, p = 0.006, HR 0.72, CI 0.43-1.13, p = 0.152, respectively).

CONCLUSIONS

Our results suggest that racial disparities in survival may be mediated by clinical and treatment parameters.

Cancer health disparities in racial/ethnic minorities in the United States

There are well-established disparities in cancer incidence and outcomes by race/ethnicity that result from the interplay between structural, socioeconomic, socio-environmental, behavioural and biological factors. However, large research studies designed to investigate factors contributing to cancer aetiology and progression have mainly focused on populations of European origin. The limitations in clinicopathological and genetic data, as well as the reduced availability of biospecimens from diverse populations, contribute to the knowledge gap and have the potential to widen cancer health disparities. In this review, we summarise reported disparities and associated factors in the United States of America (USA) for the most common cancers (breast, prostate, lung and colon), and for a subset of other cancers that highlight the complexity of disparities (gastric, liver, pancreas and leukaemia). We focus on populations commonly identified and referred to as racial/ethnic minorities in the USA-African Americans/Blacks, American Indians and Alaska Natives, Asians, Native Hawaiians/other Pacific Islanders and Hispanics/Latinos. We conclude that even though substantial progress has been made in understanding the factors underlying cancer health disparities, marked inequities persist. Additional efforts are needed to include participants from diverse populations in the research of cancer aetiology, biology and treatment. Furthermore, to eliminate cancer health disparities, it will be necessary to facilitate access to, and utilisation of, health services to all individuals, and to address structural inequities, including racism, that disproportionally affect racial/ethnic minorities in the USA.

Association between leukemia incidence and mortality and residential petrochemical exposure: A systematic review and meta-analysis

BACKGROUND

The global burden of leukemia, which grew by 19% from 2007 to 2017, poses a threat to human development and global cancer control. Factors contributing to this growth include massive industrial pollution, especially from large-scale petrochemical industry complexes (PICs). Globally, around 700 PICs are continuously operating. Data on the impact of PICs on leukemia incidence and mortality in residents are sparse and inconsistent.

OBJECTIVE

To determine the association between residential exposure to PICs and leukemia incidence and mortality using systematic review and meta-analysis.

METHODS

The studies were identified through seven databases (Clinical Key, Cochrane Library, EBSCOhost, Embase, PubMed, ScienceDirect, and Web of Science). We screened the eligibility of studies using following criteria: (1) observational studies that focused on residential exposure to PICs; (2) exposure group that was defined as residents living close to PICs; (3) outcome that was defined as all leukemia incidence and mortality; and (4) available population data. We applied the Grading of Recommendations Assessment, Development, and Evaluation to assess the certainty of evidence. The random-effects model used to estimate the pooled effects in the meta-analysis.

RESULTS

We identified thirteen epidemiologic studies (including eleven for leukemia incidence, one for leukemia mortality, and one for both), covering 125,580 individuals from Croatia, Finland, Italy, Serbia, Spain, Sweden, Taiwan, the United Kingdom, and the United States. We found moderate certainty of evidence indicated the risk of leukemia incidence (relative risk [RR] = 1.18; 95% CI = 1.03-1.35) and mortality (RR = 1.26; 95% CI = 1.10-1.45) in residents living close to PICs. Our subgroup analysis found increased RRs for leukemia incidence in studies using distance-based exposure indicator (RR = 1.11; 95% CI = 1.00-1.23), and with longer follow-up periods (RR = 1.24; 95% CI = 1.06-1.45).

CONCLUSION

Our analysis provides low-certainty evidence of increased leukemia incidence and moderate-certainty evidence of increased leukemia mortality among residents living close to PICs. While the global petrochemicals sector is growing, our findings suggest the need to consider disease prevention and pollution control measures during the development of PICs.

The Genome in a Three-Dimensional Context: Deciphering the Contribution of Noncoding Mutations at Enhancers to Blood Cancer

Associations between blood cancer and genetic predisposition, including both inherited variants and acquired mutations and epimutations, have been well characterized. However, the majority of these variants affect noncoding regions, making their mechanisms difficult to hypothesize and hindering the translation of these insights into patient benefits. Fueled by unprecedented progress in next-generation sequencing and computational integrative analysis, studies have started applying combinations of epigenetic, genome architecture, and functional assays to bridge the gap between noncoding variants and blood cancer. These complementary tools have not only allowed us to understand the potential malignant role of these variants but also to differentiate key variants, cell-types, and conditions from misleading ones. Here, we briefly review recent studies that have provided fundamental insights into our understanding of how noncoding mutations at enhancers predispose and promote blood malignancies in the context of spatial genome architecture.

Association between the TPMT*3C (rs1142345) Polymorphism and the Risk of Death in the Treatment of Acute Lymphoblastic Leukemia in Children from the Brazilian Amazon Region

Acute lymphoblastic leukemia (ALL) is the leading cause of death from pediatric cancer worldwide. However, marked ethnic disparities are found in the treatment of childhood ALL with less effective results and higher mortality rates being obtained in populations with a high level of Native American ancestry. Genetic variations of the patient can affect resistance to ALL chemotherapy and potentially play an important role in this disparity. In the present study, we investigated the association of 16 genetic polymorphisms with the cell and metabolic pathways of the chemotherapeutic agents used in the treatment of ALL with the risk of death in treating childhood ALL in patients with a high contribution of Amerindian ancestry, coming from the Brazilian Amazon. The study included 121 patients with B-cell ALL treated with the BFM-2002 protocol. We are the first to identify the association between the TPMT gene rs1142345 polymorphism and the high risk of death in treating childhood ALL. Patients with the CC genotype had an approximately 25.5 times higher risk of dying during treatment of the disease than patients with other genotypes (p = 0.019). These results may help elucidate how the patient's genetic characteristics contribute to the mortality disparity in populations with a high contribution of Native American ancestry. The rs1142345 variant of the TPMT gene could be used as a potential marker to early stratify patients at high risk of death in treating childhood ALL in the investigated population.

Prospective patient-reported symptom profiles associated with pediatric acute lymphoblastic leukemia relapse

PURPOSE

Despite improvements in frontline pediatric acute lymphoblastic leukemia (ALL) treatment, relapse remains a concern. Research in adult cancer patients suggests that patient-reported symptoms may predict survival, but the relationship between symptoms and relapse for pediatric ALL has received little attention.

METHODS

Pediatric patients with ALL (age 2-18 years) and/or their primary caregivers completed symptom surveys at the end of induction, start of delayed intensification (DI), start of maintenance cycle 1 (MC1), and start of maintenance cycle 2 (MC2). Symptom clusters for co-occurring fatigue, pain, sleep disruptions, and nausea were defined using latent profile analysis. Hazard ratios (HR) and 95% confidence intervals (CI) for the association between symptom clusters, individual symptoms, and subsequent relapse were calculated using multivariable Cox proportional hazards models, adjusting for clinical and demographic factors.

RESULTS

Eligible patients (n = 208) were followed an average of 2.6 years for the incidence of relapse (n = 22). Associations between relapse and symptoms were identified for fatigue at DI (HR = 1.83, 95%CI 1.23-2.73) and MC1 (HR = 2.14, 95%CI 1.62-2.84), pain at DI (HR = 1.80, 95%CI 1.19-2.72), nausea at the end of induction (HR = 1.19, 95%CI 1.01-1.39), and sleep disturbances at the end of induction (HR = 2.00, 95%CI 1.11-3.62), DI (HR = 1.73, 95%CI 1.01-2.96), and MC1 (HR = 2.19, 95%CI 1.10-4.35). Symptom clusters comprised of individuals with a higher average symptom burden at DI were significantly (p < 0.05) associated with relapse.

CONCLUSION

Patient-reported symptoms may provide prognostic information to aid in the identification of pediatric ALL patients at increased risk of relapse.

Area deprivation is associated with poorer overall survival in children with acute lymphoblastic leukemia

BACKGROUND

Few studies have evaluated social determinants of outcomes disparities for children with acute lymphoblastic leukemia (ALL). We investigated the association of area deprivation index (ADI), a measure of neighborhood socioeconomic disadvantage, with overall survival (OS) among children and adolescents with ALL.

PROCEDURE

We obtained demographic and clinical data, geocoded addresses at diagnosis, and vital status on all Texas children diagnosed with ALL from 1995 to 2011 (N = 4104). Using the US Census Bureau 2010 geography, we computed ADI scores for all census tracts in Texas and grouped the tracts into quartiles: least, third-most, second-most, and most disadvantaged. We mapped children to ADI quartiles based on residence at diagnosis, and estimated OS using Cox regression adjusting for sex, race/ethnicity, age, and metropolitan/nonmetropolitan residence.

RESULTS

Five-year OS ranged from 89% (95% confidence interval [CI] 87-91%) for children in the least disadvantaged tracts to 79% (95% CI 76-81%) for children in the most disadvantaged tracts (P = 4E-7). An elevated hazard ratio (HR) for death was observed for children in the most disadvantaged tracts (HR 1.57, 95% CI 1.23-2.00), and trends toward increased mortality were observed in the third-most and second-most disadvantaged tracts (HR 1.23, 95% CI 0.97-1.57 and HR 1.27, 95% CI 0.99-1.62, respectively). In stratified analyses, area disadvantage was more strongly associated with OS in males than females.

CONCLUSIONS

Neighborhood socioeconomic disadvantage is associated with inferior OS in this analysis of over 4100 children with ALL, highlighting the substantial contributions of social-environmental factors to childhood cancer survival. This association was stronger in males than females.

Differing interpretations of health care encounters: A qualitative study of non-Latinx health care providers' perceptions of Latinx patient behaviors

INTRODUCTION

Due to provider shortages, it is probable that non-Latinx health care providers (HCPs) will treat Latinx patients. Because of this discrepancy, both providers and patients are likely to experience barriers and cultural differences during medical encounters. This article discusses select cultural factors and behaviors such as language, communication styles, and health care practices of Latinx families through the lens of their non-Latinx HCPs. The purpose of this study was to examine how non-Latinx HCPs perceive and describe certain behaviors they observe during healthcare visits with Latinx patients and families, and to illustrate how those behaviors can alternatively be interpreted as representing Latinx cultural norms.

METHODS

This qualitative study used a template coding approach to examine narrative interviews conducted with 18 non-Latinx HCPs to report how they described interactions with and the behaviors of their Latinx patients. Template codes were based on well-established Latinx cultural norms (e.g., familismo, respeto, personalismo, simpatía, confianza).

RESULTS

Many HCP descriptions of Latinx patient behaviors were coded into the Latinx cultural values categories (familismo, personalismo, simpatía, respeto, and confianza) by the research team. Results suggest that HCPs were not aware of how several of their patients' behaviors may be culturally grounded, and that cultural differences between HCPs and their Latinx patients may exist.

DISCUSSION

Understanding how Latinx-specific cultural norms may be exhibited by Latinx patients and their families during healthcare encounters has potential to improve providers' understanding of patient behavior, helping to promote culturally congruent care for Latinxs.

Association Between Depth of Neutropenia and Clinical Outcomes in Febrile Pediatric Cancer and/or Patients Undergoing Hematopoietic Stem-cell Transplantation

BACKGROUND

Infectious Diseases Society of America guidelines defines febrile neutropenia (FN) patients as high risk, if they have an absolute neutrophil count (ANC) ≤100 cells/µL anticipated to last >7 days. However, data evaluating the clinical significance of the depth and duration of neutropenia are limited.

METHODS

We conducted a retrospective cohort study of pediatric oncology patients presenting with FN to examine whether the effects of the depth and duration of neutropenia prior to presentation were predictive of blood stream infection (BSI), invasive fungal disease (IFD), pediatric intensive care unit (PICU) admission or length of stay.

RESULTS

A total of 585 FN episodes (FNEs) were identified in 265 patients. ANC at the time of presentation was <100 in 411 (70%), 100-500 in 119 (20%), and >500 cells/μL with subsequent decline to <500 cells/μL in the next 48 hours in 55 (10%) of FNEs. In the group with ANC > 500 with subsequent decline in 48 hours, rates of IFD and BSI were higher when compared with ANC < 100 cells/μL [odds ratio (OR) = 5.9, 95% confidence interval (CI): 0.7-29.6] and (OR = 2.35, 95% CI: 01.02-5.4), and patients in this group were more likely to be admitted to the PICU (OR= 5.1, 95% CI: 1.134-19.46). No difference in outcomes was identified when the groups of ANC < 100 and ANC of 100-500 cells/μL were compared. Neutropenia >7 days prior to FNE was an independent risk factor for BSI (OR = 2.88, 95% CI: 1.55-5.35 and increased length of stay.

CONCLUSIONS

Clinicians should not be reassured when patients present with FN and initial ANC >500 cells/mL after recent chemotherapy if continued decline is expected as patients in this group are at high risk of IFD, BSI and PICU admission.

Characterization of pharmacogenetic markers related to Acute Lymphoblastic Leukemia toxicity in Amazonian native Americans population

Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children. Differences are found among ethnic groups in the results of the treatment of pediatric ALL. In general, children with a high level of native American ancestry tend to respond less positively to ALL treatments, which may be related to specific genomic variants found in native American groups. Despite the evidence, few data are available on the distribution of the pharmacogenomic variants relevant to the treatment of ALL in traditional Amerindian populations, such the those of the Amazon region. Given this, the present study investigated 27 molecular markers related to the treatment of ALL in Amerindians from Brazilian Amazonia and compared the frequencies with those recorded previously on five continents, that are available in the 1,000 Genomes database. The variation in the genotype frequencies among populations was evaluated using Fisher's exact test. The False Discovery Rate method was used to correct the results of the multiple analyses. Significant differences were found in the frequencies of the majority of markers between the Amerindian populations and those of other regions around the world. These findings highlight the unique genetic profile of the indigenous population of Brazilian Amazonia, which may reflect a distinct therapeutic profile for the treatment of ALL in these populations.

Geographic Variations of Racial/Ethnic Disparities in Late-Stage Diagnosis of Childhood Cancer in Texas

OBJECTIVES

This study aimed to identify small geographic areas where the childhood cancer yearly incidence and late-stage diagnosis rates were disproportionately higher among racial/ethnic minorities (Hispanics and non-Hispanic African Americans) in Texas.

METHODS

The study examined childhood cancer disparities in Texas from 2005 to 2014, based on geographic location and race/ethnicity. Relative (risk ratio) and absolute (risk difference) measures were used to investigate racial disparities of childhood cancer late-stage diagnosis in small geographic areas (census tracts). The study investigated childhood cancer yearly incidence- and late-stage diagnosis rates for three racial groups combined. The study also analyzed the temporal change of childhood cancer late-stage diagnosis rates based on the data from census tracts where disparities existed for Hispanics and non-Hispanic African Americans compared with a non-Hispanic white reference group.

RESULTS

A total of 54% of the cases in the study cohort were diagnosed in the late stage. Although there were fewer non-Hispanic African Americans cases compared with non-Hispanic white and Hispanic cases, they showed significant geographic variation in racial/ethnic disparities compared with the non-Hispanic white reference group. The study also revealed that 58 census tracts for non-Hispanic African Americans and 47 census tracts for Hispanics (of 5265) had significantly higher late-stage diagnosis rates compared with non-Hispanic whites. The findings also demonstrated consistent increases in incidence and late-stage diagnosis from 2005 to 2014 for all cases combined.

CONCLUSIONS

Most of the significant census tracts with a higher late-stage diagnosis rate for Hispanics were located on the outskirts of the Dallas-Fort Worth, Houston, and San Antonio areas. In contrast, geographic disparities of childhood cancer late-stage diagnosis for non-Hispanic African Americans were found inside the large metropolitan areas of Houston and Dallas-Fort Worth. The findings of this study will help prioritize the geographical allocation of resources, which, in turn, will help to facilitate preventive healthcare services and alleviate the disease burden in children.

The effect of insurance status on overall survival among children and adolescents with cancer

Background

Differences in access, delivery and utilisation of health care may impact childhood and adolescent cancer survival. We evaluated whether insurance coverage impacts survival among US children and adolescents with cancer diagnoses, overall and by age group, and explored potential mechanisms.

Methods

Data from 58 421 children (aged ≤14 years) and adolescents (15–19 years), diagnosed with cancer from 2004 to 2010, were obtained from the National Cancer Database. We examined associations between insurance status at initial diagnosis or treatment and diagnosis stage; any treatment received; and mortality using logistic regression, Cox proportional hazards (PH) regression, restricted mean survival time (RMST) and mediation analyses.

Results

Relative to privately insured individuals, the hazard of death (all-cause) was increased and survival months were decreased in those with Medicaid [hazard ratio (HR) = 1.27, 95% confidence interval (CI): 1.22 to 1.33; and −1.73 months, 95% CI: −2.07 to −1.38] and no insurance (HR = 1.32, 95% CI: 1.20 to 1.46; and −2.13 months, 95% CI: −2.91 to −1.34). The HR for Medicaid vs. private insurance was larger (pinteraction &lt;0.001) in adolescents (HR = 1.52, 95% CI: 1.41 to 1.64) than children (HR = 1.16, 95% CI: 1.10 to 1.23). Despite statistical evidence of PH assumption violation, RMST results supported all interpretations. Earlier diagnosis for staged cancers in the Medicaid and uninsured populations accounted for an estimated 13% and 19% of the survival deficit, respectively, vs. the privately insured population. Any treatment received did not account for insurance-associated survival differences in children and adolescents with cancer.

Conclusions

Children and adolescents without private insurance had a higher risk of death and shorter survival within 5 years following cancer diagnosis. Additional research is needed to understand underlying mechanisms.

The Role of ARID5B in Acute Lymphoblastic Leukemia and Beyond

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children with distinct characteristics among different subtypes. Although the etiology of ALL has not been fully unveiled, initiation of ALL has been demonstrated to partly depend on genetic factors. As indicated by several genome wide association studies (GWASs) and candidate gene analyses, ARID5B, a member of AT-rich interactive domain (ARID) protein family, is associated with the occurrence and prognosis of ALL. However, the mechanisms by which ARID5B genotype impact on the susceptibility and treatment outcome remain vague. In this review, we outline developments in the understanding of ARID5B in the susceptibility of ALL and its therapeutic perspectives, and summarize the underlying mechanisms based on the limited functional studies, hoping to illustrate the possible mechanisms of ARID5B impact and highlight the potential treatment regimens.

Treatment Complications and Survival Among Children and Young Adults With Acute Lymphoblastic Leukemia

PURPOSE

We previously demonstrated lower early mortality for young adults (YAs) with acute lymphoblastic leukemia (ALL) who received induction treatment at specialized cancer centers (SCCs) versus community hospitals. The aim of this study is to determine the impact of inpatient location of treatment throughout therapy on long-term survival, complications, and cost-associations that have not yet been evaluated at the population level.

METHODS

Using the California Cancer Registry linked to a hospitalization database, we identified patients, 0-39 years of age, diagnosed with first primary ALL who received inpatient treatment between 1991 and 2014. Patients were classified as receiving all or part or none of their inpatient treatment at an SCC within 3 years of diagnosis. Inverse probability-weighted, multivariable Cox regression models estimated the associations between location of treatment and sociodemographic and clinical factors with survival. We compared 3-year inpatient costs overall and per day by age group and location of care.

RESULTS

Eighty-four percent (0-18 years; n = 4,549) of children and 36% of YAs (19-39 years; n = 683) received all treatment at SCCs. Receiving all treatment at an SCC was associated with superior leukemia-specific (hazard ratio [HR], 0.76; 95% CI, 0.67 to 0.88) and overall survival (HR, 0.87; 95% CI, 0.77 to 0.97) in children and in YAs (HR, 0.71; 95% CI, 0.61 to 0.83; HR, 0.70; 95% CI, 0.62 to 0.80) even after controlling for complications. The cost of inpatient care during the full course of therapy was higher in patients receiving all of their care at SCCs.

CONCLUSION

Our results demonstrate that inpatient treatment at an SCC throughout therapy is associated with superior survival; therefore, strong consideration should be given to referring these patients to SCCs.

Epidemiology and Etiology of Leukemia and Lymphoma

Available evidence suggests that the incidence of leukemia and lymphoma tends to be higher in highly developed regions of the world and among Whites in the United States. Temporal trends in incidence are dynamic and multifactorial; for instance, the incidence of non-Hodgkin's lymphoma increased around the turn of the century, in part because of the acquired immune deficiency syndrome (AIDS) epidemic. Most leukemias and lymphomas are sporadic and the specific etiology remains elusive. Still, research shows that these malignancies often develop in the context of genetic abnormalities, immunosuppression, and exposure to risk factors like ionizing radiation, carcinogenic chemicals, and oncogenic viruses. The prognosis varies by subtype, with poorer survival outcomes for acute leukemias among adults, and more favorable outcomes for Hodgkin's lymphoma. At a time when specific prevention efforts targeting these malignancies are nonexistent, there is a great need to ensure equitable access to diagnostic services and treatments worldwide.

High Rates of Obesity at Presentation Persist into Survivorship across Childhood Cancer Types

Background: Subtypes of pediatric oncology patients and childhood cancer survivors who are overweight or obese have worse prognosis than their healthy-weighted peers. Several studies have examined weight status in either pediatric patients or survivors with acute leukemia, but few have compared these data across various diagnoses. Objectives: We examined BMI from oncology diagnosis or presentation, through treatment, and into survivorship across the most common cancer types seen in pediatric oncology. Methods: Patients were categorized into three oncologic diagnoses: leukemia and lymphoma (n = 69), neural tumors (n = 80), and non-neural solid tumors (n = 80) at yearly intervals over the course of 11 years. To allow for comparisons across age groups, BMI percentiles were calculated with <5th percentile classified as underweight (n = 11), the 5th-84th percentile classified as a healthy weight (n = 129), and above the 85th percentile classified as overweight and obese (n = 87). Results: At presentation, 45.6% of leukemia and lymphoma patients were overweight or obese, and 44.3% of neural tumor patients were overweight or obese. These high obesity rates persisted into survivorship. Compared to the non-neural tumor group, the leukemia and lymphoma group had a significant increase in BMI percentile over time, while the neural tumor group did not. Conclusions: Pediatric patients with leukemia, lymphoma, and neural tumors and who are overweight or obese at presentation continue this trend into survivorship, indicating a need for management of overweight and obesity through lifestyle interventions concurrent with therapy.

Assessment of enrollment characteristics for Children's Oncology Group (COG) upfront therapeutic clinical trials 2004-2015

Background

Improvements in pediatric cancer survival are attributed to cooperative clinical trials. Under-representation of specific demographic groups has been described in adult and pediatric cancer trials and poses a threat to the generalizability of results. An evaluation of data provided by the Children’s Oncology Group (COG) of upfront trial enrollment for US patients 0 to 29 years old between 2004 and 2015 was performed.

Methods

US cancer cases were estimated using incidence data and US population estimates from the Surveillance, Epidemiology, and End Results Program and compared to observed COG cases. Percent enrollment and standardized ratios of enrollment were calculated across demographic, disease, and socioeconomic groups. The COG website was utilized to quantify available trials and assess age eligibility.

Results

19.9% of estimated US cancer patients age 0 to 19 years enrolled on COG trials. Younger patients were more represented across diseases and races/ethnicities. Patients with hematologic malignancies were more represented compared to solid and central nervous system (CNS) tumors.

Conclusion

COG trial enrollment rates are declining when compared to previously published data, potentially from challenges in pediatric drug development, difficulty designing feasible trials for highly curable diagnoses, and issues ensuring trial availability for the heterogeneous group of solid and CNS tumors. Though racial/ethnic groups and county-level socioeconomic factors were proportionally represented, under representation of the adolescent/young adult (AYA) population and younger patients with solid and CNS tumors remains a concern. Targeted efforts should focus on these subgroups and further research should evaluate AYA enrollment rates across all available trials.