Genomics of racial and ethnic disparities in childhood acute lymphoblastic leukemia

The Relationship between Health Disparities, Psychosocial Functioning and Health Outcomes in Pediatric Hematology-Oncology and Stem Cell Transplant Populations: Recommendations for Clinical Care

Not only do racial and ethnic minority children and adolescents with chronic illness experience disparities in health status and health outcomes, they also experience significant healthcare disparities, including differences in healthcare coverage, access to care, and quality of care. It is well known that the interaction between psychosocial functioning, health behaviors and ethnic and racial disparities, ultimately leads to worse health and psychosocial outcomes in pediatric and AYA chronic illness patient populations, including increased rates of morbidity and mortality. Investigating the impact of racial and ethnic factors on health outcomes, and strategies for reducing these disparities, is of the utmost importance, specifically in life-threatening conditions like cancer and sickle cell disease. This commentary underscores the relative importance of identifying factors that could reduce disparities between minority and non-minority populations. This present paper will focus on the dynamic relationships between health disparities, psychosocial factors and health outcomes within pediatric cancer, sickle cell disease and bone marrow transplant populations, and will offer recommendations for healthcare professionals working with these vulnerable patient populations. The primary goal of this commentary is to provide recommendations for enhancing cultural competency and humility for those working with highly vulnerable patient populations.

The Longitudinal Parallel Process Analysis of Biomarkers of Oxidative Stress, Symptom Clusters, and Cognitive Function in Children With Leukemia

Background: During treatment for acute lymphoblastic leukemia (ALL), children report co-occurring symptoms of fatigue, sleep disturbance, pain, nausea, and depression as a symptom cluster. Central nervous system-directed ALL therapies also put children at risk for cognitive impairments. Cancer therapies can cause an increase in oxidative stress, which may contribute to treatment-related symptoms. This study examined the longitudinal relationships between biomarkers of oxidative stress in the cerebrospinal fluid, the Childhood Cancer Symptom Cluster-Leukemia (CCSC-L), and cognition, in children over the first year of ALL treatment. Methods: Glutathione (GSH) biomarkers of oxidative stress were measured in cerebrospinal fluid collected during treatment lumbar punctures. GSH biomarkers, symptoms, and cognitive function of 132 children aged 3 to 18 years were evaluated at four time points during the first year of leukemia treatment. Participants, 7 years and older, completed self-report measures, and parents reported for younger children. Cognitive function measurements for all participants were completed by parents. A longitudinal parallel-process model was used to explore the influence of the initial measurement and the subsequent change over four time points of the GSH biomarkers on the CCSC-L and cognition. Results: GSH biomarkers increased over the four time points indicating decreasing oxidative stress. When GSH biomarkers were higher (less oxidative stress) at the initial measurement, the CCSC-L severity was lower, cognition was better, and cognition improved over the four measurements. Screening children for high levels of oxidative stress would be a foundation for future intervention studies to address symptom distress and cognitive impairments.

Mutation analysis in Korean patients with T-cell acute lymphoblastic leukemia

Genomic studies have illuminated the alterations in pathways underlying T-cell acute lymphoblastic leukemia (T-ALL) pathogenesis, but detailed mutation data by next-generation sequencing have not been reported in Korean patients. We aimed to investigate mutation frequency, spectrum, and pattern in the Korean patients with T-ALL. We designed a multigene panel targeting 101 genes and validated it using 10 reference materials. The mutation analysis was done in a total of 10 patients with T-ALL. Clinical data and laboratory tests including immunophenotyping, cytogenetics, and molecular genetic tests were also investigated. All of the 10 patients harbored at least one mutation (range 1-6 per patient). A total of 34 clinically significant mutations including 15 novel mutations were identified in 23 genes. The median of variant allelic frequencies (VAFs) and blasts were counted upto 33% (range 5-91%) and 79% (range 38-90%), respectively. Recurrent mutations were involved in epigenetic regulators (60%), NOTCH1 signaling (40%), PI3K-AKT (40%), JAK-STAT (30%), and transcription factors (30%). We found that both NOTCH signaling and JAK-STAT signaling were positively associated with epigenetic regulators, while showed mutually exclusive patterns with PI3K-AKT pathway. This study showed that the frequency of mutations in epigenetic regulators in Korean patients was significantly higher than expected. Distribution of VAF as well as mutation spectrum is considerably heterogeneous in Korean patients with T-ALL. Although from a limited number of patients, this study provides the first detailed mutational portrait of T-ALL of Korean patients, and gives additional insight into molecular pathogenesis of the disease.

Poorer outcome of childhood acute lymphoblastic leukemia in the Bedouin population: A report from the Berlin-Frankfurt-Muenster-based Israeli national protocols

BACKGROUND

Therapy outcomes for childhood acute lymphoblastic leukemia (ALL) had substantially improved in the last decades, but variability across racial and ethnic groups was identified in some clinical studies. In this study, we aimed to investigate whether such a difference in outcome is found in the diverse ethnicities in Israel as well.

METHODS

A retrospective study was conducted among 1154 patients (855 Jews, 195 Muslims, 52 Bedouins, 26 Druze, and 26 others) aged 1 to 21 years, who were diagnosed with ALL between 1989 and 2011 and were treated according to the same Berlin-Frankfurt-Muenster-based Israel National Study protocols.

RESULTS

Bedouins had a higher incidence of t(1;19) (16% vs 3% for non-Bedouins) and a lower incidence of high-hyperdiploidy (10% vs 25% for non-Bedouins) (P = 0.01). Five-year event-free survival (EFS) and overall survival (OS) were poorer for the Bedouins (60.3% ± 7.2% and 63.1% ± 7.2%, respectively) compared with the Jews, Muslims, and Druze (80.4% ± 1.4%, 77.3% ± 3.2%, and 84% ± 7.3%, respectively, for EFS [P = 0.02], and 86.3% ± 1.2%, 82.3% ± 2.9%, and 88.3% ± 6.4%, respectively, for OS [P = 0.002]). Adherence to intensive chemotherapy was similar between the Muslims and the Bedouins.

CONCLUSIONS

Our findings suggest that the Bedouins, a highly inbred ethnic Arab people, may be considered a higher risk group that may need more intensive chemotherapy and/or supportive care in order to improve their outcome.

Safety of standardised treatments for haematologic malignancies as regards to testicular endocrine function in children and teenagers

STUDY QUESTION

Does standardised treatments used in children and adolescents with haematologic malignancies, including acute lymphoblastic (ALL) or myeloid leukaemia (AML) and non-Hodgkin lymphoma (NHL), affect endocrine function of the developing testes?

SUMMARY ANSWER

Therapy of haematologic malignancies do not provoke an overt damage of Sertoli and Leydig cell populations, as revealed by normal levels of anti-Müllerian hormone (AMH) and testosterone, but a mild primary testicular dysfunction may be observed, compensated by moderate gonadotropin elevation, during pubertal development.

WHAT IS KNOWN ALREADY

Evidence exists on the deleterious effect that chemotherapy and radiotherapy have on germ cells, and some attention has been given to the effects on Leydig and Sertoli cells of the adult gonads, but information is virtually non-existent on the effects of oncologic treatment on testicular somatic cell components during childhood and adolescence.

STUDY DESIGN, SIZE, DURATION

A retrospective, analytical, observational study included 97 boys with haematological malignancies followed at two tertiary paediatric public hospitals in Buenos Aires, Argentina, between 2002 and 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clinical records of males aged 1-18 years, referred with the diagnoses of ALL, AML or NHL for the assessment of gonadal function, were eligible. We assessed serum levels of AMH and FSH as biomarkers of Sertoli cell endocrine function and testosterone and LH as biomarkers of Leydig cell function.

MAIN RESULTS AND THE ROLE OF CHANCE

All hormone levels were normal in the large majority of patients until early pubertal development. From Tanner stage G3 onwards, while serum AMH and testosterone kept within the normal ranges, gonadotropins reached mildly to moderately elevated values in up to 35.9% of the cases, indicating a compensated Sertoli and/or Leydig cell dysfunction, which generally did not require hormone replacement therapy.

LIMITATIONS, REASONS FOR CAUTION

Serum inhibin B determination and semen analysis were not available for most patients; therefore, we could not conclude on potential fertility impairment or identify whether primary Sertoli cell dysfunction resulted in secondary depleted spermatogenesis or whether primary germ cell damage impacted Sertoli cell function.

WIDER IMPLICATIONS OF THE FINDINGS

The regimens used in the treatment of boys and adolescents with ALL, AML or NHL in the past two decades seem relatively safe for endocrine testicular function; nonetheless, a mild primary testicular endocrine dysfunction may be observed, usually compensated by slightly elevated gonadotropin secretion by the pituitary in adolescents, and not requiring hormone replacement therapy. No clinically relevant risk factor, such as severity of the disease or treatment protocol, could be identified in association with the compensated endocrine dysfunction.

STUDY FUNDING/COMPETING INTEREST(S)

This work was partially funded by grants PIP 11220130100687 of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and PICT 2016-0993 of Fondo para la Investigación Científica y Tecnológica (FONCYT), Argentina. R.A.R., R.P.G. and P.B. have received honoraria from CONICET (Argentina) for technology services using the AMH ELISA. L.A.A. is part-time employee of CSL Behring Argentina. The other authors have no conflicts of interest to disclose.

Myosteatosis in adolescents and young adults treated for acute lymphoblastic leukemia

Myosteatosis refers to fat deposition within muscle and is linked to risk of cardiovascular disease and metabolic disorders. Though these comorbidities are common during and after therapy for acute lymphoblastic leukemia (ALL), little is known about tissue distribution, including myosteatosis, in this population. Using quantitative computed tomography, we assessed the impact of ALL therapy on bone, muscle, subcutaneous, and muscle-associated (MA) fat in 12 adolescents and young adults (AYA) treated for ALL as compared to a healthy control group without ALL (n = 116). AYA had a marked loss of muscle with a gain in MA fat between ALL diagnosis and end of induction. These changes persisted throughout intensive therapy. Lower bone and muscle and higher MA fat were also observed during and after treatment in comparison to controls. Altered lower extremity tissue distribution, specifically myosteatosis and sarcopenia, may contribute to functional declines and increased risk of metabolic disorders and cardiovascular diseases.

Effect of socio-economic status & proximity of patient residence to hospital on survival in childhood acute lymphoblastic leukaemia

Background & objectives:

Survival in paediatric acute lymphoblastic leukaemia (ALL) in lower/middle income countries continues to lag behind outcomes seen in high-income countries. Socio-economic factors and distance of their residence from the hospital may contribute to this disparity. This study was aimed at identifying the impact of these factors on outcome in childhood ALL.

Methods:

In this retrospective study, file review of children with ALL was performed. Patients were treated with the modified United Kingdom (UK) ALL-2003 protocol. Details of socio-economic/demographic factors were noted from a web-based patients’ database. Modified Kuppuswamy scale was used to classify socio-economic status.

Results:

A total of 308 patients with a median age of five years (range: 1-13 yr) were studied. Patients belonging to upper, middle and lower SE strata numbered 85 (28%), 68 (22%) and 155 (50%). Nearly one-third of the patients were underweight. There was no treatment abandonment among children whose mothers were graduates. Neutropenic deaths during maintenance therapy were lower in mothers who had passed high school. In patients who survived induction therapy, the five year event-free survival (EFS) of upper SE stratum was significantly better 78.7±4.9 vs. 59±7.2 and 58.1±4.6 per cent in middle and lower strata (P=0.026). Five year overall survival was higher in the higher SE group; being 91.2±3.5, 78.3±5.6 and 78.8±3.9 per cent (P=0.055) in the three strata. Survival was unaffected by a distance of residence from treating centre or rural/urban residence. High-risk and undernourished children had a greater hazard of mortality [1.80 (P=0.015); 1.98 (P=0.027)].

Interpretation & conclusions:

Our findings showed that higher socio-economic status contributed to superior EFS in children with ALL who achieved remission. Undernutrition increased the risk of mortality.

Precision medicine and health disparities: The case of pediatric acute lymphoblastic leukemia

BACKGROUND

Precision medicine has uncertain potential to address population health disparities.

PURPOSE

Case study of disparities in pediatric acute lymphoblastic leukemia (ALL).

METHOD

Literature-based evaluation of ALL in African American (AA) and European American (EA) children.

FINDINGS

AA children have a lower incidence of ALL than EA children, experience higher relapse rates, and are more likely to be diagnosed with poor prognostic indicators. Environmental risk exposures for ALL have small effect sizes; data are insufficient to determine their contribution to differences in incidence and prognosis. Differences in prevalence of gene variants associated with treatment response contribute to higher relapse rates in AA children. However, higher relapse rates were not seen in a care setting that eliminated out of pocket costs, used risk-directed therapy, and included rigorous case management.

DISCUSSION

Unequal access to effective treatment contributes to ALL disparities. Precision medicine can help to define effective treatment for diverse patient populations.

Decreased Early Mortality in Young Adult Patients With Acute Lymphoblastic Leukemia Treated at Specialized Cancer Centers in California

PURPOSE

Studies suggest that patients with acute lymphoblastic leukemia (ALL) have superior survival when treated at specialized cancer centers (SCCs). However, the association of early mortality (< 60 days) with location of initial care, sociodemographic factors, and complications has not been evaluated in pediatric and young adult (YA) patients with ALL.

METHODS

Using the California Cancer Registry linked to hospitalization data, we identified pediatric and YA patients with ALL who received inpatient leukemia treatment between 1991 and 2014. Patients were classified as receiving all or part/none of their care at an SCC (Children's Oncology Group- or National Cancer Institute-designated cancer center). Propensity scores were created for treatment at an SCC in each age group. Multivariable, inverse probability-weighted Cox proportional hazards regression models identified factors associated with early mortality. Results are presented as hazard ratios (HRs) and 95% CIs.

RESULTS

Among 6,531 newly diagnosed pediatric (≤ 18 years) and YA (19 to 39 years of age) patients with ALL, 1.6% of children and 5.4% of YAs died within 60 days of diagnosis. Most children received all of their care at an SCC (n = 4,752; 85.7%) compared with 35.5% of YAs (n = 1,779). Early mortality rates were lower in pediatric patients and those receiving all care at an SCC (pediatric: all, 1.5%, v part/none, 2.4%; P = .049; YAs: all, 3.2%, v part/none, 6.6%; P = .001). However, in adjusted models, receiving all care at an SCC was associated with significantly lower early mortality in YAs (HR, 0.51; 95% CI, 0.32 to 0.81), but not in pediatric patients (HR, 0.77; 95% CI, 0.47 to 1.25).

CONCLUSION

YAs with ALL experience significant reductions in early mortality after treatment at SCCs.

Early vs. late MRD response- and risk-based treatment intensification of childhood acute lymphoblastic leukemia: a prospective pilot study from Saudi Arabia

Background

Refinement of risk-based treatment stratification by minimal residual disease (MRD) at different time points has improved outcomes of childhood acute lymphoblastic leukemia (ALL). In this prospective study we evaluated effects of such stratification, including intensification of therapy based on response assessment at day-15 and MRD at day-29 of induction to test if treatment intensification would improve outcomes.

Methods

241 patients, 1-14 years old, newly diagnosed with ALL, were recruited and stratified by risk and MRD response into three treatment Arms (A, B, or C). Arm A was modified from COG AALL0331, B from AALL0232, and C from AALL0232 and AALL0434. Assignments were according to NCI risk, phenotype, rapid vs. slow early response (SER), steroid pretreatment, MLL rearrangement (MLLR), CNS3, and testicular involvement. Patients on Arm A had treatment intensified early based on day-15 marrow results or late based on end-of-induction MRD.

Results

5-year OS, EFS, and CIR were 89.5% ± 4.0%, 87.6% ± 4.3%, and 7.1% ± 3.5%. No significant difference was found by B- vs. T cell phenotype. 5-year OS, EFS, and CIR for B-cell ALL were 90.5% ± 2.4%, 88.7% ± 2.6%, and 6.4% ± 2.0%. Outcomes for patients with t(1;19)/TCF3-PBX1 and MLLR were significantly (p ≤ 0.05) worse than for other patients. MRD level at end-of-induction associated with outcomes, but association with a specific MRD value at end-of-induction varied significantly by NCI-risk group. Late treatment intensification based on end-of-induction MRD significantly improved survival outcomes for NCI-SR patients, however, patients with NCI-HR and positive MRD at end-of-induction had significantly inferior outcomes despite intensification. MRD transitions between day-15 and day-29 of induction associated with differences for OS and EFS.

Conclusions

Arm switching to a more intensive protocol had mixed results. Assigning patients by end-of-induction MRD-risk alone did not reflect response kinetics of the different NCI-risk groups. Although late treatment intensification improved outcomes of NCI-SR patients with positive MRD at end-of-induction, further refinement is needed to improve outcomes of NCI-HR with SER. Integration of NCI-risk group with specific MRD value and time point allows more refined treatment stratification.Trial Registration Protocols were approved by King Abdullah International Medical Research Center and Ethics Review Committee RC08053J.

Cancer Statistics for Hispanics/Latinos, 2018

Cancer is the leading cause of death among Hispanics/Latinos, who represent the largest racial/ethnic minority group in the United States, accounting for 17.8% (57.5 million) of the total population in the continental United States and Hawaii in 2016. In addition, more than 3 million Hispanic Americans live in the US territory of Puerto Rico. Every 3 years, the American Cancer Society reports on cancer occurrence, risk factors, and screening for Hispanics in the United States based on data from the National Cancer Institute, the North American Association of Central Cancer Registries, and the Centers for Disease Control and Prevention. For the first time, contemporary incidence and mortality rates for Puerto Rico, which has a 99% Hispanic population, are also presented. An estimated 149,100 new cancer cases and 42,700 cancer deaths will occur among Hispanics in the continental United States and Hawaii in 2018. For all cancers combined, Hispanics have 25% lower incidence and 30% lower mortality compared with non-Hispanic whites, although rates of infection-related cancers, such as liver, are up to twice as high in Hispanics. However, these aggregated data mask substantial heterogeneity within the Hispanic population because of variable cancer risk, as exemplified by the substantial differences in the cancer burden between island Puerto Ricans and other US Hispanics. For example, during 2011 to 2015, prostate cancer incidence rates in Puerto Rico (146.6 per 100,000) were 60% higher than those in other US Hispanics combined (91.6 per 100,000) and 44% higher than those in non-Hispanic whites (101.7 per 100,000). Prostate cancer is also the leading cause of cancer death among men in Puerto Rico, accounting for nearly 1 in 6 cancer deaths during 2011-2015, whereas lung cancer is the leading cause of cancer death among other US Hispanic men combined. Variations in cancer risk are driven by differences in exposure to cancer-causing infectious agents and behavioral risk factors as well as the prevalence of screening. Strategies for reducing cancer risk in Hispanic populations include targeted, culturally appropriate interventions for increasing the uptake of preventive services and reducing cancer risk factor prevalence, as well as additional funding for Puerto Rico-specific and subgroup-specific cancer research and surveillance.

Cancer Incidence Among Children in New Caledonia, 1994 to 2012

New Caledonia (NC) is a small French territory in the Pacific Ocean with a relatively young (32% under 20) and multiethnic population. It is divided into 3 districts: Loyalty Island, the North, and the South, each with specific population characteristics. The aim of this study was to describe childhood cancer age-standardized incidence rate (ASR) in NC, compare it with the estimated one in France , and to determine whether residence and ethnicity may have an influence on intrapopulation ASR. All incident cancer cases diagnosed between 1994 and 2012 in children (0 to 14 y) resident in NC for more than 6 months were included. With 162 registered cases, the ASR for all cancers combined was 142.2 (range, 104.9 to 193.3) cases per million children per year and was not different from what was estimated in France (156.6). However, incidence varies according to the place of residence, with a higher ASR in the Loyalty Island district for several types of neoplasms, but not according to the ethnicity. The small migratory flux between this district and the rest of the territory may have led to these results, but, because of the small number of cases, no conclusion can be drawn.

IFNG +874 A/T is associated with acute lymphoblastic leukemia in Mexican Mestizos

Acute lymphoblastic leukemia (ALL), the most common type of cancer in children worldwide, has one of the highest incidence rates in Mexico. It is a multifactorial disease and different cytokine single nucleotide polymorphisms (SNP), have been associated with ALL expression. Few studies have been published analyzing IFNG +874 T/A and IL2 -330 G/T in this type of leukemia. These SNPs are involved in high or low expression, and are central to cellular immunity, influencing greatly tumor growth. The purpose of this work was to explore the association of IFNG +874 A/T (rs2430561) and IL2 -330 G/T (rs2069762) SNPs with ALL susceptibility and/or protection in 488 Mexican Mestizos patients, as compared to 950 Mexican Mestizo healthy controls. The results demonstrated that IFNG +874 T allele (pc = 0.00004, OR = 0.673) and the TT genotype (pc = 0.00015, OR = 0.349), protect against ALL expression with no specific gender association; however, the TT homozygote genotype (vs. TA+AA) seems more protective in males (pc = 0.00683). IL2 -330 G/T does not contribute to the development of ALL. In healthy Mexicans, the most common genotypes for IL2 and IFNG, are the low cytokine producers, suggesting that the genetic background in this ethnic group, may be partly responsible for the high incidence of ALL. These results show for the first time in Mexicans, the relevant role that IFNG SNP has in the genetic etiology of ALL. Thus, a large group of patients belonging to different ethnicities will be very helpful to study in order to demonstrate if these SNPs contribute to the genetic etiology of ALL, as shown here in Mexican Mestizos.

Genetic Mutations in B-Acute Lymphoblastic Leukemia Among African American and European American Children

BACKGROUND

The survival of patients with B-acute lymphoblastic leukemia (B-ALL) is significantly lower in African American (AA) children compared with European American children (EA). Here, we present a whole exome sequencing (WES) study showing race-specific genetic variations that may play a role on the disparate outcomes among AA and EA children with B-ALL.

PATIENTS AND METHODS

Five AA and 15 EA patients ranging in age from 1 to 18 years were enrolled. The median blast percentage was 94.8% (range, 64.5%-99.9%). Frozen bone marrow aspirate was used to extract DNA, and WES was performed, focusing on race and B-ALL-specific germline mutations.

RESULTS

Most genetic variants (n = 339) were shared between AA and EA children. Some genetic aberrations were only uniquely identified in AA (n = 58) and others in EA (n = 52) In AA, the genetic aberrations clustered in canonical pathways related to telomerase signaling and cancer signaling. In EA, the unique genetic aberration clustered in pathways related to stem cell pluripotency and hereditary cancer.

CONCLUSIONS

Our study revealed aberrant genetic aberrations in signaling networks that may contribute to race-specific aspects of leukemogenesis. Our results suggest the value of WES as a tool for development of individual gene signatures and gene scores for AA and EA children afflicted by B-ALL. These findings may ultimately impact disease management and contribute to the elimination of disparate outcomes in AA children with B-ALL.

Revisiting the complete blood count and clinical findings at diagnosis of childhood acute lymphoblastic leukemia: 10-year experience at a single center

Background

Heterogeneity regarding clinical and laboratory findings at diagnosis of acute lymphoblastic leukemia exists. The frequency of complete blood count abnormalities and its combinations, symptoms and physical findings were investigated in Hispanic children from an open population at the diagnosis of acute lymphoblastic leukemia.

Methods

The patient charts and electronic records of under 16-year-old children diagnosed with acute lymphoblastic leukemia over 10 years at a regional hematology center of a university hospital were analyzed to retrieve data concerning the complete blood count at first evaluation. Type and distribution of abnormal data, frequency of symptoms and physical findings at presentation were documented.

Results

The records of 203 children aged 0–15 years diagnosed with acute lymphoblastic leukemia from 2006 to 2016 were revisited. The results of the blood workup showed a median white blood cell count of 7120 × 10⁹/L (range: 450–600,000 × 10⁹/L), and a median hemoglobin concentration of 7.5 g/dL (range: 2.4–15.3 g/dL), whereas the median platelet count was 47,400 × 10⁹/L (range: 4000–544,000 × 10⁹/L). Leukocytosis and leukopenia were present in 36.6% and 36.1% of cases, respectively; anemia was diagnosed in 82.9% children. The order of frequency for major clinical symptoms was fatigue 62%, fever 60%, bone and joint pain 39%, hyporexia 33% and weight loss 21%, while main physical findings were hepatomegaly 78%, splenomegaly 63%, lymphadenopathy 57%, pallor 48%, and purpura 30%.

Conclusion

Data differing from those classically expected at diagnosis of acute lymphoblastic leukemia in children were documented in a cohort of Hispanic children over one decade with a wide spectrum of complete blood count abnormalities, forms of presentation and frequency of physical findings.

Hispanic Ethnicity and the Risk of Pediatric Leukemia Relapse

Limited knowledge currently exists on the disparity in pediatric leukemia relapse. This study compared the risk of pediatric leukemia relapse between Hispanic and non-Hispanic Whites. Study participants were children (<20 years) diagnosed with leukemia from January 2006 to December 2014 at the Johns Hopkins All Children's Hospital, St. Petersburg, Florida. Hazard ratios and 95% confidence intervals for relapse-free survival were calculated using adjusted Cox regression. The study included 35 Hispanic and 94 non-Hispanic Whites. Among patients <10 years old, there was a significantly higher risk of relapse in Hispanic compared to non-Hispanic Whites (hazard ratio = 6.19, 95% confidence interval = 1.15-33.27). No association was observed for patients aged ≥10 years nor all participants combined. Although the finding of this study may suggest that ethnic disparity in pediatric leukemia relapse may exist in younger children, our finding is limited by the small sample size from a single institution. Therefore, future larger multiinstitutional studies are warranted.

An investigation of toxicities and survival in Hispanic children and adolescents with ALL: Results from the Dana-Farber Cancer Institute ALL Consortium protocol 05-001

PURPOSE

This study compared the relative incidence of treatment-related toxicities and the event-free and overall survival between Hispanic and non-Hispanic children undergoing therapy for acute lymphoblastic leukemia (ALL) on Dana-Farber Cancer Institute ALL Consortium protocol 05-001.

PATIENTS AND METHODS

Secondary analysis of prospectively collected data from a phase III multicenter study in children and adolescents of 1-18 years with previously untreated ALL.

RESULTS

Between 2005 and 2011, 794 eligible patients enrolled on DFCI 05-001, 730 of whom were included in this analysis (19% [N = 150] Hispanic, 73% [N = 580] non-Hispanic). Hispanic patients were more likely to be ≥10 years of age (32% vs. 24%, P = 0.045) at diagnosis. Toxicity analyses revealed that Hispanic patients had significantly lower cumulative incidence of bone fracture (P < 0.001) and osteonecrosis (ON; P = 0.047). In multivariable risk regression, the risk of ON was significantly lower in Hispanic patients ≥10 years (HR 0.23; P = 0.006). Hispanic patients had significantly lower 5-year event-free survival (EFS) (79.4%; 95% CI: 71.6-85.2) and overall survival (OS) (89.2%; 95% CI: 82.7-93.4) than non-Hispanic patients (EFS: 87.5%; 95% CI: 84.5-90.0, P = 0.004; OS: 92.7%; 95% CI: 90.2-94.6, P = 0.006). Exploratory analyses revealed differences between Hispanic and non-Hispanic patients in the frequency of common variants in genes related to toxicity or ALL outcome.

CONCLUSION

Hispanic children treated for ALL on DFCI 05-001 had fewer bone-related toxicities and inferior survival than non-Hispanic patients. While disease biology is one explanatory variable for outcome disparities, these findings suggest that biologic and non-biologic mechanisms affecting drug delivery and exposure in this population may be important contributing factors as well.

Gene polymorphisms in the folate metabolic pathway and risk of pediatric acute lymphoblastic leukemia: a case-control study in a Chinese population

Polymorphisms in folate pathway genes may influence susceptibility to pediatric acute lymphoblastic leukemia (ALL). This case-control study was undertaken to analyze the association of genetic polymorphisms (677C>T and 1298A>C) of methylenetetrahydrofolate reductase (MTHFR) and reduced folate carrier (RFC1) (80G>A) with the risk of pediatric ALL in China. A total of 176 pediatric ALL patients and 170 matched healthy subjects (as controls) were included and DNA was extracted from the peripheral blood. SNaPshot single nucleotide polymorphism typing was used to determine the genotypes of MTHFR 677C>T, MTHFR 1298A>C, and RFC1 80G>A. All statistical analyses were conducted with SAS software (version 9.2; SAS Institute). There were no significant differences in the genotype and allele frequencies of MTHFR 677C>T, MTHFR 1298A>C, or RFC1 80G>A between patients and controls. No significant correlation was found between the combined genotypes of these polymorphisms and the risk of developing ALL in this study. Furthermore, no significant differences were observed for 677C>T and 1298A>C frequencies between the control and case groups. There was no association between MTHFR 677C>T, MTHFR 1298A>C, or RFC1 80G>A gene polymorphisms and risk of pediatric ALL in the Han Chinese population.

Prognostic Effect of CD20 Expression in Adult B-cell Acute Lymphoblastic Leukemia

INTRODUCTION

The expression of the CD20 on adult B-cell acute lymphoblastic leukemia (ALL-B) has generally been associated with a poor prognosis, and several studies have explored the incorporation of rituximab into the therapeutic regimen for adult ALL-B patients, with a positive effect on event-free survival (EFS).

PATIENTS AND METHODS

We analyzed the prognostic value of CD20 expression and the effect of rituximab for the treatment of Hispanic adult ALL-B patients. We performed a retrospective study of 152 ALL-B patients treated from 2009 to 2016. The patient characteristics and treatment outcomes were analyzed according to CD20 expression (CD20⁺ vs. CD20^-), age group, and treatment with rituximab.

RESULTS

CD20 expression was positive for 47.7% of patients (n = 72). Excluding the patients who had received rituximab, the overall survival (OS) was greater for the CD20^- patient subgroup than for the CD20⁺ subgroup (11.2 vs. 6.9 months; 95% confidence interval [CI], 7.43-14.9; P = .008). In the CD20⁺ subgroup, 10 patients (7.2%) received treatment with rituximab, with 100% reaching complete remission (CR) 4 weeks after treatment. In the 18- to 39-year age group, CD20⁺ patients treated with rituximab had EFS and OS that was not reached. In addition, for CD20⁺ patients who received with chemotherapy, EFS was 3.9 months (95% CI, 0.6-7.2 months; P = .025) and OS was 7.2 months (95% CI, 3.37-11.0; P = .013). Multivariate analysis showed that the use of rituximab was independently associated with OS and CR at 4 weeks after induction.

CONCLUSION

CD20 expression in adult ALL-B is associated with decreased OS. Treatment with rituximab can increase OS, EFS, and CR in the 18- to 39-year age group.

Acculturation, Mental Health, and Quality of Life among Hispanic Childhood Cancer Survivors: A Latent Class Analysis

Objective

Acculturation appears to be an important aspect of the association between ethnicity and disease, but it has not been explored in depth among childhood cancer survivors (CCS). The purpose of our study was to identify distinct acculturative profiles among Hispanic CCS and to assess differences in quality of life and depressive symptoms.

Design

Latent class analysis was used to identify distinct acculturative profiles using 9 indicator items reflecting Hispanic and Anglo cultural orientation. Multinomial logistic regression was performed to explore differences in depressive symptoms and quality of life between acculturation classes.

Setting and Participants

Participants were diagnosed in Los Angeles County, California, USA between 2000-2007 and were recruited for the study in 2009.

Main Outcome Measures

Center for Epidemiologic Studies depression scale and the PedsQL 4.0 quality of life scale.

Results

Three distinct acculturation classes emerged. All classes displayed a high probability of endorsing all Anglo orientation items. One class additionally demonstrated a high probability of endorsing all Hispanic orientation items and was labeled bicultural 40%); another demonstrated low probability of endorsing the Hispanic items so was labeled assimilated (32%); and the last demonstrated a high probability of endorsing only the Hispanic items related to language use and was labeled linguistically Hispanic/culturally Anglo (LH) (28%).

Conclusions

The assimilated group had significantly more depressive symptoms and lower quality of life than the other two groups. This may indicate that loss of the Hispanic culture may be associated with poorer psychosocial health among CCS.

Racial Differences in Four Leukemia Subtypes: Comprehensive Descriptive Epidemiology

Leukemia is a malignant progressive disease and has four major subtypes. Different racial groups differ significantly in multiple aspects. Our goal is to systematically and comprehensively quantify racial differences in leukemia. The SEER database is analyzed, and comprehensive descriptive analysis is provided for the four major subtypes, namely ALL (acute lymphoblastic leukemia), CLL (chronic lymphoblastic leukemia), AML (acute myeloid leukemia), and CML (chronic myeloid leukemia), and for two age groups (≤14 and >14) separately. The racial groups studied include NHW (non-Hispanic White), HW (Hispanic White), BL (Black), and API (Asian and Pacific Islander). Univariate and multivariate analyses are conducted to quantify racial differences in patients’ characteristics, incidence, and survival. For patients’ characteristics, significant racial differences are observed in gender, age at diagnosis, diagnosis era, using radiation for treatment, registry, cancer history, and histology type. For incidence, significant racial differences are observed, and the patterns vary across subtypes, gender, and age groups. For most of the subtypes and gender and age groups, Blacks have the worst five-year survival, and significant racial differences exist. This study provides a comprehensive epidemiologic description of racial differences for the four major leukemia subtypes in the U.S. population.

Survival among children diagnosed with acute lymphoblastic leukemia in the United States, by race and age, 2001 to 2009: Findings from the CONCORD-2 study

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. This report describes the survival of children with ALL in the United States using the most comprehensive and up-to-date cancer registry data.

METHODS

Data from 37 state cancer registries that cover approximately 80% of the US population were used. Age-standardized survival up to 5 years was estimated for children aged 0-14 years who were diagnosed with ALL during 2 periods (2001-2003 and 2004-2009).

RESULTS

In total, 17,500 children with ALL were included. The pooled age-standardized net survival estimates for all US registries combined were 95% at 1 year, 90% at 3 years, and 86% at 5 years for children diagnosed during 2001-2003, and 96%, 91%, and 88%, respectively, for those diagnosed during 2004-2009. Black children who were diagnosed during 2001-2003 had lower 5-year survival (84%) than white children (87%) and had less improvement in survival by 2004-2009. For those diagnosed during 2004-2009, the 1-year and 5-year survival estimates were 96% and 89%, respectively, for white children and 96% and 84%, respectively, for black children. During 2004-2009, survival was highest among children aged 1 to 4 years (95%) and lowest among children aged <1 year (60%).

CONCLUSIONS

The current results indicate that overall net survival from childhood ALL in the United States is high, but disparities by race still exist, especially beyond the first year after diagnosis. Clinical and public health strategies are needed to improve health care access, clinical trial enrollment, treatment, and survivorship care for children with ALL. Cancer 2017;123:5178-89. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

A systematic review and meta-analysis of the association between childhood infections and the risk of childhood acute lymphoblastic leukaemia

Background:

To determine whether childhood infections were associated with the development of childhood acute lymphoblastic leukaemia (ALL).

Methods:

We included studies that assessed any infection in childhood prior to the diagnosis of ALL in children aged 0–19 years compared to children without cancer. The primary analysis synthesised any infection against the odds of ALL, and secondary analyses assessed the frequency, severity, timing of infections, and specific infectious agents against the odds of ALL. Subgroup analyses by data source were investigated.

Results:

In our primary analysis of 12 496 children with ALL and 2 356 288 children without ALL from 38 studies, we found that any infection was not associated with ALL (odds ratio (OR)=1.10, 95% CI: 0.95–1.28). Among studies with laboratory-confirmed infections, the presence of infections increased the odds of ALL by 2.4-fold (OR=2.42, 95% CI: 1.54–3.82). Frequency, severity, and timing of infection were not associated with ALL.

Conclusions:

The hypothesis put forward by Greaves and others about an infectious aetiology are neither confirmed nor refuted and the overall evidence remains inadequate for good judgement. The qualitative difference in the subgroup effects require further study, and future research will need to address the challenges in measuring infectious exposures.

Racial and ethnic disparities in a national cohort of ampullary cancer patients

BACKGROUND AND OBJECTIVES

Racial and ethnic variations have been described in the different malignancies, but no such data exists for ampullary cancer. The aim of this study was to present an updated report on the epidemiology, treatment patterns, and survival of a national cohort of ampullary cancer patients.

METHODS

Patients diagnosed with ampullary cancer between 2004 and 2014 were identified in the National Cancer Database. Overall survival was estimated and compared between racial/ethnic groups using the log-rank test.

RESULTS

A total of 14 879 patients were identified; 78% of the patients were White, 9% Hispanic, 8% Black, and 5% Asian. We noted significant differences in disease presentation, socioeconomic status, and outcomes. Blacks had the lowest median overall survival at 18.9 months followed by Whites at 23.9 months, Hispanics at 32.7 months, and Asians at 37.4 months. On a multivariate Cox proportional-hazards model, being Black was associated with worse survival compared to being White while being Asian and Hispanic were associated with better survival.

CONCLUSIONS

Overall survival of ampullary cancer patients was independently associated with race and ethnicity. Further studies are needed to clarify whether these disparities are primarily due to socioeconomic status or biologic factors.

Conceptualising paediatric health disparities: a metanarrative systematic review and unified conceptual framework

OBJECTIVE

There exists a paucity of work in the development and testing of theoretical models specific to childhood health disparities even though they have been linked to the prevalence of adult health disparities including high rates of chronic disease. We conducted a systematic review and thematic analysis of existing models of health disparities specific to children to inform development of a unified conceptual framework.

METHODS

We systematically reviewed articles reporting theoretical or explanatory models of disparities on a range of outcomes related to child health. We searched Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus (database inception to 9 July 2015). A metanarrative approach guided the analysis process.

RESULTS

A total of 48 studies presenting 48 models were included. This systematic review found multiple models but no consensus on one approach. However, we did discover a fair amount of overlap, such that the 48 models reviewed converged into the unified conceptual framework. The majority of models included factors in three domains: individual characteristics and behaviours (88%), healthcare providers and systems (63%), and environment/community (56%), . Only 38% of models included factors in the health and public policies domain.

CONCLUSIONS

A disease-agnostic unified conceptual framework may inform integration of existing knowledge of child health disparities and guide future research. This multilevel framework can focus attention among clinical, basic and social science research on the relationships between policy, social factors, health systems and the physical environment that impact children's health outcomes.

Racial and Ethnic Differences in Socioeconomic Position and Risk of Childhood Acute Lymphoblastic Leukemia

Racial and ethnic differences in associations between socioeconomic position (SEP) and risk of childhood acute lymphoblastic leukemia (ALL) were investigated using data from population-based cancer registries in the Surveillance, Epidemiology, and End Results Program in the United States. The study included 8,383 ALL cases diagnosed at age ≤19 years in 2000-2010. Census tract-level composite SEP index in quintiles was assigned based on residence at the time of diagnosis. Incidence rate ratios and 95% confidence intervals associated with SEP and race/ethnicity, adjusted for sex, age, and year of diagnosis, were estimated using Poisson regression models. The incidence rate of childhood ALL was negatively associated with SEP among Hispanics but was positively associated among children of other races/ethnicities. As compared with the lowest SEP, the adjusted incidence rate ratios for children with the highest SEP were 1.29 (95% confidence interval (CI): 1.15, 1.44) for non-Hispanic whites, 1.67 (95% CI: 1.20, 2.34) for non-Hispanic blacks, 1.57 (95% CI: 1.17, 2.09) for Asians/Pacific Islanders, 2.33 (95% CI: 0.93, 5.83) for American Indians/Alaska Natives, and 0.70 (95% CI: 0.60, 0.81) for Hispanics. The findings of a reverse association in Hispanics need to be confirmed and further explained in future studies using different measures of SEP.

Ph-like acute lymphoblastic leukemia: a high-risk subtype in adults

Philadelphia chromosome (Ph)-like acute lymphoblastic leukemia (ALL) is a high-risk subtype of ALL in children. There are conflicting data on the incidence and prognosis of Ph-like ALL in adults. Patients with newly diagnosed B-cell ALL (B-ALL) who received frontline chemotherapy at MD Anderson Cancer Center underwent gene expression profiling of leukemic cells. Of 148 patients, 33.1% had Ph-like, 31.1% had Ph+, and 35.8% had other B-ALL subtypes (B-other). Within the Ph-like ALL cohort, 61% had cytokine receptor-like factor 2 (CRLF2) overexpression. Patients with Ph-like ALL had significantly worse overall survival (OS), and event-free survival compared with B-other with a 5-year survival of 23% (vs 59% for B-other, P = .006). Sixty-eight percent of patients with Ph-like ALL were of Hispanic ethnicity. The following were associated with inferior OS on multivariable analysis: age (hazard ratio [HR], 3.299; P < .001), white blood cell count (HR, 1.910; P = .017), platelet count (HR, 7.437; P = .005), and Ph-like ALL (HR, 1.818; P = .03). Next-generation sequencing of the CRLF2+ group identified mutations in the JAK-STAT and Ras pathway in 85% of patients, and 20% had a CRLF2 mutation. Within the CRLF2+ group, JAK2 mutation was associated with inferior outcomes. Our findings show high frequency of Ph-like ALL in adults, an increased frequency of Ph-like ALL in adults of Hispanic ethnicity, significantly inferior outcomes of adult patients with Ph-like ALL, and significantly worse outcomes in the CRLF2+ subset of Ph-like ALL. Novel strategies are needed to improve the outcome of these patients.

Inferior outcomes for black children with high risk acute lymphoblastic leukemia and the impact of socioeconomic variables

BACKGROUND

While significant improvements have been made for children with acute lymphoblastic leukemia (ALL) in the United States over the past 20 years, black patients continue to have inferior outcomes. The full impact of socioeconomic variables on outcomes in this minority population is not entirely understood.

PROCEDURE

Disease characteristics, demographic, and socioeconomic status (SES) variables were collected on black (n = 44) and white (n = 178) patients diagnosed at the University of Alabama at Birmingham. Cox proportional hazard regression was used to evaluate the influence of SES and insurance status on survival.

RESULTS

As a cohort, 5-year overall survival (OS) was 87% (82-91%), with a median follow-up of 99 months. In univariable analysis, black race was not significantly associated with a higher risk of death or relapse and death. White and black patients with standard-risk leukemia had excellent outcomes, with 97% (91-99%) and 96% (75-99%) 5-year OS, respectively. In contrast, for high-risk disease, white patients had a statistically significant improved 5-year OS rates compared with black patients (79% [68-87%] vs. 52% [28-72%]). Black children were more likely to have public insurance, and, in multivariable analysis, this was associated with a trend toward an improved outcome. Black patients also had poorer census tract-level SES parameters, but these variables were not associated with survival.

CONCLUSION

Our study demonstrates significantly inferior outcomes for black children with high-risk leukemia. These outcome disparities were not related to SES variables, including poverty or private insurance coverage, suggesting the involvement of other factors and highlighting the need for a prospective investigative analysis.

Brain structure, working memory and response inhibition in childhood leukemia survivors

INTRODUCTION

Survival rates for children with acute lymphoblastic leukemia (ALL) approach 95%. At the same time, there is growing concern that chemotherapy causes alterations in brain development and cognitive abilities. We performed MRI measurements of white and gray matter volume to explore how variation in brain structure may be related to cognitive abilities in ALL survivors and healthy controls.

METHODS

The sample included 24 male ALL survivors who had completed contemporary treatment 3-11 years prior, and 21 age- and sex-matched controls. Participants were between 8 and 18 years old. Working memory and motor response inhibition were measured with the N-Back and Stop Signal Tasks (SST), respectively. Participants underwent 3T structural MRI to assess white and gray matter volumes overall, lobe-wise, and in cortical and atlas-identified subcortical structures. Mental health was assessed with the Child Behavioral Checklist.

RESULTS

ALL survivors performed more poorly on measures of working memory and response inhibition than controls. Frontal and parietal white matter, temporal and occipital gray matter volume, and volumes of subcortical white and gray matter structures were significantly reduced in ALL survivors compared with controls. Significant structure-function correlations were observed between working memory performance and volume of the amygdala, thalamus, striatum, and corpus callosum. Response inhibition was correlated with frontal white matter volume. No differences were found in psychopathology.

CONCLUSIONS

Compared with controls, a reduction in volume across brain regions and tissue types, was detectable in ALL survivors years after completion of therapy. These structural alterations were correlated with neurocognitive performance, particularly in working memory. Confirming these observations in a larger, more representative sample of the population is necessary. Additionally, establishing the time course of these changes-and the treatment, genetic, and environmental factors that influence them-may provide opportunities to identify at-risk patients, inform the design of treatment modifications, and minimize adverse cognitive outcomes.

[Acute lymphoblastic leukemia: a genomic perspective]

In parallel to the human genome sequencing project, several technological platforms have been developed that let us gain insight into the genome structure of human entities, as well as evaluate their usefulness in the clinical approach of the patient. Thus, in acute lymphoblastic leukemia (ALL), the most common pediatric malignancy, genomic tools promise to be useful to detect patients at high risk of relapse, either at diagnosis or during treatment (minimal residual disease), and they also increase the possibility to identify cases at risk of adverse reactions to chemotherapy. Therefore, the physician could offer patient-tailored therapeutic schemes. A clear example of the useful genomic tools is the identification of single nucleotide polymorphisms (SNPs) in the thiopurine methyl transferase (TPMT) gene, where the presence of two null alleles (homozygous or compound heterozygous) indicates the need to reduce the dose of mercaptopurine by up to 90% to avoid toxic effects which could lead to the death of the patient. In this review, we provide an overview of the genomic perspective of ALL, describing some strategies that contribute to the identification of biomarkers with potential clinical application.

Tobacco Smoke and Ras Mutations Among Latino and Non-Latino Children with Acute Lymphoblastic Leukemia

BACKGROUND AND AIMS

Childhood acute lymphoblastic leukemia (ALL) is a biologically heterogeneous disease, and mutations in the KRAS and NRAS oncogenes are present at diagnosis in about one-fifth of cases. Ras mutations were previously associated with environmental exposures in leukemias as well as in many other cancer types. This study examined whether Ras mutation could define a unique etiologic group of childhood ALL associated with tobacco smoke, a well-established mutagen and carcinogen.

METHODS

We included 670 children with ALL enrolled in a case-control study in California (1995-2013), including 50.6% Latinos. Parental and child exposure to tobacco smoke was obtained from interviews. Sanger sequencing was used to detect the common KRAS and NRAS hotspot mutations in diagnostic bone marrow DNA. ALL cases were also characterized for common chromosome abnormalities. In case-case analyses, logistic regression analyses were used to estimate odds ratios to describe the association between tobacco smoke exposure and childhood ALL with Ras mutations.

RESULTS

KRAS or NRAS mutations were detected in ∼18% of children diagnosed with ALL. Ras mutations were more common among Latino cases compared with non-Latino whites and in high-hyperdiploid ALL. No associations were observed between parental smoking or child's passive exposure to smoke and Ras positive ALL.

CONCLUSIONS

The apparent lack of association between tobacco smoke and Ras mutation in childhood ALL suggests that Ras mutations do not specifically define a tobacco-related etiologic pathway. Reasons for racial and ethnic differences in ALL are not well understood and could reflect differences in etiology that warrant further examination.

Delays in postremission chemotherapy for Philadelphia chromosome negative acute lymphoblastic leukemia are associated with inferior outcomes in patients who undergo allogeneic transplant: An analysis from ECOG 2993/MRC UK ALLXII

Adults with acute lymphoblastic leukemia (ALL) have a poorer prognosis than children due to a high risk of relapse. One explanation may be variable adherence to dose-intense chemotherapy. However, little is known about risk factors for delays in therapy and their impact on survival. We conducted an analysis of ECOG 2993/UKALLXII trial to study delays in postremission chemotherapy in adults with newly diagnosed ALL. Logistic regression was used to identify risk factors for a very long delay (VLD, >4 weeks) in start of intensification therapy. Cox regression was used to evaluate the impact of delays on overall survival (OS) and event-free survival (EFS). We evaluated 1076 Philadelphia chromosome negative (Ph-) patients who completed induction chemotherapy, achieved complete remission, and started intensification. Factors independently associated with VLD included duration of hospitalization (odds ratio [OR] = 1.2, P < 0.001) during Phase I; thrombocytopenia during Phase I (OR = 1.16, P = 0.004) or Phase II (OR 1.13, P = 0.001); chemotherapy dose reductions during Induction Phase I (OR = 1.72, P < 0.014); female sex (OR = 1.53, P = 0.010); Black (OR = 3.24, P = 0.003) and Asian (OR = 2.26, P = 0.021) race; and increasing age (OR = 1.31, P < 0.001). In multivariate Cox regression, patients who underwent allogeneic stem cell transplant (alloHCT) had significantly worse OS (HR 1.4, P = 0.03) and EFS (HR 1.4, P = 0.02) after experiencing a VLD compared to alloHCT patients who experienced ≤4 weeks delay. Specific populations (female, older, Black, and Asian patients) were more likely to experience delays in chemotherapy, as were those with significant toxicity during induction. VLDs in therapy negatively affected outcomes in patients undergoing allografting. Am. J. Hematol. 91:1107-1112, 2016. © 2016 Wiley Periodicals, Inc.

Treatment-related adverse events associated with a modified UK ALLR3 induction chemotherapy backbone for childhood relapsed/refractory acute lymphoblastic leukemia

BACKGROUND

The UK ALLR3 (R3) regimen has been adopted to treat pediatric relapsed acute lymphoblastic leukemia (ALL) by many centers in the United States and has become a preferred therapeutic backbone for testing novel agents in clinical trials. A detailed toxicity profile of this platform has not previously been reported. The toxicity and response rates for its use beyond first relapse are unknown.

PROCEDURES

We performed a multi-institutional, retrospective study including children with relapsed ALL treated with the R3 reinduction chemotherapy backbone block 1 across five pediatric centers. Data were extracted from medical records and analyzed.

RESULTS

Fifty-nine patients were included in the study, including 16 patients with ≥2nd relapse. Ninety-seven percent of patients experienced at least one Grade ≥3 nonhematologic adverse event (AE). Grade 3 or higher infection was reported in 90% of patients. Other nonhematologic Grade ≥3 AEs included electrolyte abnormalities, elevation in hepatic enzymes, and pain. Eighty-five percent of patients achieved a complete remission (CR). There were no significant differences in the incidence of AEs, CR rate, and rate of minimal residual disease negativity between patients with 1st or ≥2nd relapse.

CONCLUSION

Our study confirmed that R3 block 1 is a highly active reinduction regimen in childhood relapsed ALL. However, it was associated with a high incidence of severe toxicities, particularly infection. The toxicity profiled in our report should be used to inform optimal supportive care and future clinical trial design with the R3 backbone, particularly when new agents are combined with this regimen.

DNA methylation and leukemia susceptibility in China: Evidence from an updated meta-analysis

Mounting evidence supports a role for DNA methylation in the pathogenesis of leukemia; however, there no overview of these results in the Chinese population. The present study performed a comprehensive meta-analysis to establish candidate genes with an altered methylation status in Chinese leukemia patients. Eligible studies were identified through searching the National Center of Biotechnology Information PubMed and Wanfang databases. Studies were pooled and overall odds ratios with corresponding confidence intervals were calculated. A total of 4,325 leukemia patients and 2,010 controls from 94 studies on 53 genes were included in this meta-analysis, and 47 genes were found to be aberrantly methylated in leukemia patients. A further subgroup meta-analysis by leukemia subtype demonstrated that hypermethylation of 5 genes, namely cyclin-dependent kinase (CDKN)2A, DNA-binding protein inhibitor-4, CDKN2B, glioma pathogenesis-related protein 1 and p73, contributed to the risk of various subtypes of leukemia. In addition, a strong association between CDKN2A and leukemia was identified in Chinese (P<0.00001) but not in European patients. The aberrantly methylated genes identified in the present meta-analysis may help elucidate the mechanisms underlying the development of leukemia in Chinese patients.

Prevalence and Predictors of Overweight and Obesity Among a Multiethnic Population of Pediatric Acute Lymphoblastic Leukemia Survivors: A Cross-Sectional Assessment

As previous studies of obesity in survivors of pediatric acute lymphoblastic leukemia (ALL) have primarily been conducted among non-Hispanic white survivors or children treated on older protocols, our objective was to describe the prevalence and correlates of overweight status among an ethnically diverse population of pediatric ALL survivors, largely treated with more contemporary therapies. We evaluated the overweight/obesity status of pediatric ALL survivors (n=406) followed in the Texas Children's Cancer Center between 2004 and 2014. Survivors were classified as underweight, normal weight, overweight, or obese on the basis of their body mass index at their most current follow-up visit. Our results showed that Hispanic ethnicity (39% of the subjects) was associated with being overweight (adjusted odds ratio=1.88; 95% confidence interval, 1.13-3.14) or obese (adjusted odds ratio=2.84; 95% confidence interval, 1.59-5.06) at follow-up, even after adjusting for cranial radiotherapy (CRT) exposure. Body mass index z-score at diagnosis was also associated with overweight/obesity at follow-up. In addition, there was a statistically significant interaction between younger age at diagnosis and CRT, indicating that younger age at diagnosis was associated with obesity among patients who received CRT. These findings may help identify pediatric ALL patients that are at increased risk of being overweight or obese after treatment.

Variability in Cancer Risk and Outcomes Within US Latinos by National Origin and Genetic Ancestry

Latinos have lower rates for most common cancer sites and higher rates of some less common cancers (gallbladder, liver, gastric, and cervical) than other ethnic/racial groups. Latinos are a highly heterogeneous population with diverse national origins, unique genetic admixture patterns, and wide spectrum of socio-demographic characteristics. Across the major cancers (breast, colorectal, prostate, lung, and liver) US-born Latinos have higher incidence and worse survival than foreign-born, and those with low-socioeconomic status have the lowest incidence. Puerto Rican and Cuban Latinos have higher incidence rates than Mexican Latinos. We have identified the following themes as understudied and critical to reduce the cancer burden among US Latinos: (1) etiological studies considering key sources of heterogeneity, (2) culturally sensitive cancer prevention strategies, (3) description of the molecular tumor landscape to guide treatments and improve outcomes, and (4) development of prediction models of disease risk and outcomes accounting for heterogeneity of Latinos.

Maternal prenatal intake of one-carbon metabolism nutrients and risk of childhood leukemia

PURPOSE

Folate, vitamins B12 and B6, riboflavin, and methionine are critical nutrients for the one-carbon metabolism cycle involved in DNA synthesis and epigenetic processes. We examined the association between maternal intake of these nutrients before pregnancy and risk of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in a matched case-control study.

METHODS

Maternal dietary intake and vitamin supplement use in the year before pregnancy was assessed by food frequency questionnaire for 681 ALL cases, 103 AML cases, and 1076 controls. Principal component analysis was used to construct a variable representing combined nutrient intake, and conditional logistic regression estimated the odds ratio (OR) and 95% confidence interval (CI) for the association of ALL and AML with the principal component and each nutrient.

RESULTS

Higher maternal intake of one-carbon metabolism nutrients from food and supplements combined was associated with reduced risk of ALL (OR for one-unit change in the principal component = 0.91, CI 0.84-0.99) and possibly AML (OR for the principal component = 0.83, CI 0.66-1.04). When analyzed separately, intake of supplements high in these nutrients was associated with a reduced risk of ALL in children of Hispanic women only.

CONCLUSIONS

In conclusion, these data suggest that higher maternal intake of one-carbon metabolism nutrients may reduce risk of childhood leukemia.

Impact of Socioeconomic Status on Timing of Relapse and Overall Survival for Children Treated on Dana-Farber Cancer Institute ALL Consortium Protocols (2000-2010)

BACKGROUND

Population-based evidence suggests that lower socioeconomic status (SES) negatively impacts the overall survival (OS) of children with leukemia; however, the relationships between SES and treatment-related mortality, relapse, and timing of relapse remain unclear.

PROCEDURE

We examined OS, event-free survival (EFS) and cumulative incidence (CI) and timing of relapse by community-level poverty for 575 children aged 1-18 years with newly diagnosed acute lymphoblastic leukemia (ALL) treated on consecutive phase III multicenter Dana-Farber Cancer Institute ALL Consortium Protocols between 2000 and 2010. Children were categorized into high- and low-poverty areas for the analysis using aggregate U.S. Census data linked to zip code.

RESULTS

Children living in high-poverty areas experienced a 5-year OS of 85% as compared with 92% for those in low-poverty areas (P = 0.02); poverty remained marginally significant (P = 0.07) after adjustment for immunophenotype, age, and white blood cell count. There were no differences detected in EFS or CI relapse by poverty area. However, 92% of the relapses observed in children from high-poverty areas occurred <36 months from complete remission, compared to 48% of those in children from low-poverty areas (P = 0.008).

CONCLUSIONS

U.S. children with ALL living in high-poverty areas have a higher risk of early relapse when compared with those living in low-poverty areas despite uniform treatment. This may in part explain decreased OS observed in these children. This finding highlights disparities in childhood cancer outcomes by SES despite uniform treatment. Further investigations of the mechanistic pathways underlying this finding are needed.

Identification of a novel susceptibility locus at 16q23.1 associated with childhood acute lymphoblastic leukemia in Han Chinese

Recently, genome-wide association studies (GWAS) have identified several susceptibility loci for childhood acute lymphoblastic leukemia (ALL) in populations of European descent; only a few loci could be confirmed in Asian populations because of those populations' genetic heterogeneity. To identify genetic factors associated with childhood ALL risk in the Chinese population, we performed a three-stage GWAS of 1184 childhood ALL cases and 3219 non-ALL controls. The combined analysis identified a new locus (rs1121404 in WWOX) at 16q23.1 associated with childhood ALL susceptibility (odds ratio (OR) = 1.38, P = 5.29 × 10^-10), especially in the subtype of B-ALL (OR = 1.39, P = 2.47 × 10^-9). The functional studies subsequently revealed that the expression of WWOX in ALL bone marrow was significantly lower than that in normal bone marrow. The G allele of rs1121404 displayed significantly decreased levels of mRNA expression of WWOX These results suggest that WWOX plays an important role in the development of childhood ALL and provide new insights into the etiology of childhood ALL.

Predictors of early death and survival among children, adolescents and young adults with acute myeloid leukaemia in California, 1988-2011: a population-based study

A better understanding of factors associated with early death and survival among children, adolescents and young adults with acute myeloid leukaemia (AML) may guide health policy aimed at improving outcomes in these patients. We examined trends in early death and survival among 3935 patients aged 0-39 years with de novo AML in California during 1988-2011 and investigated the associations between sociodemographic and selected clinical factors and outcomes. Early death declined from 9·7% in 1988-1995 to 7·1% in 2004-2011 (P = 0·062), and survival improved substantially over time. However, 5-year survival was still only 50% (95% confidence interval 47-53%) even in the most recent treatment period (2004-2011). Overall, the main factors associated with poor outcomes were older age at diagnosis, treatment at hospitals not affiliated with National Cancer Institute-designated cancer centres, and black race/ethnicity. For patients diagnosed during 1996-2011, survival was lower among those who lacked health insurance compared to those with public or private insurance. We conclude that mortality after AML remained strikingly high in California and increased with age. Possible strategies to improve outcomes include wider insurance coverage and treatment at specialized cancer centres.

Evaluation of Pre-Hematopoietic Cell Transplantation (HCT) Brain MRI and Neurologic Complications of Pediatric Patients Undergoing HCT for Hematologic Malignancies

Adverse neurologic complications (NC) occur commonly in pediatric patients with hematologic malignancies both pre- and post-allogeneic hematopoietic cell transplant (HCT). Given this known risk, we previously obtained pre-HCT brain magnetic resonance imaging (MRI) to document baseline abnormalities but utility of this and findings are not well described. This study aimed to ( a) determine the prevalence and risk factors for abnormal brain MRI and ( b) determine prevalence and risk factors for development of new NC during and 2 years post-HCT. Retrospective chart review included 102 patients with hematologic malignancies who underwent allogeneic HCT between 2000 and 2009 at University of California San Francisco (UCSF) Children's Hospital and included standard HCT data, brain MRI reports, and NC and symptoms pre- and post-HCT. Forty-three percent of patients had abnormal findings on pre-MRI, most commonly nonspecific white matter changes. Neurologic symptoms pre-HCT was the only significant risk factor for abnormal MRI. Eleven patients (11%) developed post-HCT NC. Non-Caucasian race was the only significant risk factor for new NC. Although abnormal pre-HCT brain MRI is common, these findings are not predictive of subsequent NC post-HCT. Therefore routine surveillance may not be informative for that purpose, particularly when general anesthesia is required, which can have detrimental neurocognitive effects. Etiology of NC in pediatric HCT is likely multifactorial and may include genetic and ethnic predispositions.

A novel xenograft model to study the role of TSLP-induced CRLF2 signals in normal and malignant human B lymphopoiesis

Thymic stromal lymphopoietin (TSLP) stimulates in-vitro proliferation of human fetal B-cell precursors. However, its in-vivo role during normal human B lymphopoiesis is unknown. Genetic alterations that cause overexpression of its receptor component, cytokine receptor-like factor 2 (CRLF2), lead to high-risk B-cell acute lymphoblastic leukemia implicating this signaling pathway in leukemogenesis. We show that mouse thymic stromal lymphopoietin does not stimulate the downstream pathways (JAK/STAT5 and PI3K/AKT/mTOR) activated by the human cytokine in primary high-risk leukemia with overexpression of the receptor component. Thus, the utility of classic patient-derived xenografts for in-vivo studies of this pathway is limited. We engineered xenograft mice to produce human thymic stromal lymphopoietin (+T mice) by injection with stromal cells transduced to express the cytokine. Control (-T) mice were produced using stroma transduced with control vector. Normal levels of human thymic stromal lymphopoietin were achieved in sera of +T mice, but were undetectable in -T mice. Patient-derived xenografts generated from +T as compared to -T mice showed a 3-6-fold increase in normal human B-cell precursors that was maintained through later stages of B-cell development. Gene expression profiles in high-risk B-cell acute lymphoblastic leukemia expanded in +T mice indicate increased mTOR pathway activation and are more similar to the original patient sample than those from -T mice. +T/-T xenografts provide a novel pre-clinical model for understanding this pathway in B lymphopoiesis and identifying treatments for high-risk B-cell acute lymphoblastic leukemia with overexpression of cytokine-like factor receptor 2.

Cancer statistics for Hispanics/Latinos, 2015

Cancer is the leading cause of death among Hispanics/Latinos, who represent the largest racial/ethnic minority group in the United States, accounting for 17.4% (55.4 million/318 million) of the total US population in 2014. Every 3 years, the American Cancer Society reports on cancer statistics for Hispanics based on incidence data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data from the National Center for Health Statistics. Among Hispanics in 2015, there will be an estimated 125,900 new cancer cases diagnosed and 37,800 cancer deaths. For all cancers combined, Hispanics have 20% lower incidence rates and 30% lower death rates compared with non-Hispanic whites (NHWs); however, death rates are slightly higher among Hispanics during adolescence (aged 15-19 years). Hispanic cancer rates vary by country of origin and are generally lowest in Mexicans, with the exception of infection-associated cancers. Liver cancer incidence rates in Hispanic men, which are twice those in NHW men, doubled from 1992 to 2012; however, rates in men aged younger than 50 years declined by 43% since 2003, perhaps a bellwether of future trends for this highly fatal cancer. Variations in cancer risk between Hispanics and NHWs, as well as between subpopulations, are driven by differences in exposure to cancer-causing infectious agents, rates of screening, and lifestyle patterns. Strategies for reducing cancer risk in Hispanic populations include increasing the uptake of preventive services (e.g., screening and vaccination) and targeted interventions to reduce obesity, tobacco use, and alcohol consumption.