Children's Oncology Group's 2013 blueprint for research: epidemiology

Is There Etiologic Heterogeneity between Subtypes of Childhood Acute Lymphoblastic Leukemia? A Review of Variation in Risk by Subtype

Although substantial advances in the identification of cytogenomic subtypes of childhood acute lymphoblastic leukemia (ALL) have been made in recent decades, epidemiologic research characterizing the etiologic heterogeneity of ALL by subtype has not kept pace. The purpose of this review is to summarize the current literature concerning subtype-specific epidemiologic risk factor associations with ALL subtype defined by immunophenotype (e.g., B-cell vs. T-cell) and cytogenomics (including gross chromosomal events characterized by recurring numerical and structural abnormalities, along with cryptic balanced rearrangements, and focal gene deletions). In case-control analyses investigating nongenetic risk factors, home paint exposure is associated with hyperdiploid, MLL-rearranged, and ETV6-RUNX1 subtypes, yet there are few differences in risk factor associations between T- and B-ALL. Although the association between maternal smoking and ALL overall has been null, maternal smoking is associated with an increasing number of gene deletions among cases. GWAS-identified variants in ARID5B have been the most extensively studied and are strongly associated with hyperdiploid B-ALL. GATA3 single nucleotide variant rs3824662 shows a strong association with Ph-like ALL (OR = 3.14). However, there have been relatively few population-based studies of adequate sample size to uncover risk factors that may define etiologic heterogeneity between and within the currently defined cytogenomic ALL subtypes.

The cancer incidence and mortality among children and adolescents during the period of 2010-2014 in Henan Province, China

OBJECTIVE

The cancer etiology in children and adolescents is largely different with that in adults, and the description in epidemiology still remains deficiency. Therefore, we described the cancer incidence and related epidemiological features in children and adolescents to provide clues for etiological studies.

METHODS

Cancer incidence stratified by age, gender, and areas was calculated using data extracted from population-based cancer registries in Henan Province, China. All cancer among children aged 0-19 years were reclassified according to category criteria of the International Classification of Childhood Cancer, 3rd Edition (ICCC-3). Age-standardized rate (WSR) was calculated using Segi's world standardized population by the direct method, and it was expressed per million person-years.

RESULTS

The crude cancer incidence and mortality were 87.56 and 36.32 per million person-years among children aged 0-19 years, and the WSRs slightly changed compared with crude incidence and mortality, and they were 87.36 and 35.46 per million person-years. Leukemia and central nervous system neoplasms (CNS) were the most common cancer categories both in children aged 0-14 years and in adolescents aged 15-19 years in regardless of gender and areas. Tiny difference of incidence and mortality existed in different age groups across 0-14 years; however, they were higher in adolescents aged 15-19 years than that in children aged 0-14 years. Among children aged 0-19 years, the cancer incidence and mortality were predominant in boys, and the sex ratio was 1.19; however, it was varied by diagnostic categories.

CONCLUSION

This is the first study that described the cancer incidence and mortality among children aged 0-19 in Henan Province, and it would help researchers to understand the burden and epidemiological characteristics of childhood cancer, and hence suggested clues for the etiological studies.

The Children's Oncology Group: Organizational Structure, Membership, and Institutional Characteristics

BACKGROUND

The Children's Oncology Group (COG) is the only organization within the National Cancer Institute's National Clinical Trials Network dedicated exclusively to pediatric cancer research. The purpose of this article is to provide an overview of COG's organizational structure, to characterize its institutional and individual membership, and to summarize enrollments onto COG clinical trials.

METHOD

Data from 2013 to 2015 were compiled from sources internal (Network Operations, Statistics and Data Center, Chair's Office) and external (American Hospital Association, American Nurses Credentialing Center) to COG, to present a comprehensive overview of COG's structure, individual and institutional membership, and group operations.

RESULTS

In 2016, COG comprised 8,785 individuals from 223 member institutions, across seven countries. An average of 9,661 new patients were registered with COG per year over the most recent (2013-2015) 3-year period. Over the same 3-year time frame, there were an average of 16,836 enrollments onto therapeutic (i.e., treatment) and nontherapeutic (e.g., epidemiology, survivorship, biology) trials per year.

CONCLUSIONS

COG institutions have diverse characteristics related to size, geographical location, and infrastructure. Individual membership also reflects diversity with representation from over 28 disciplines and groups. The diversity of COG institutions and individual members allows for unique perspectives and contributions to science unified under a common goal to enroll children/adolescents onto clinical trials. COG's collaborative, multidisciplinary approach to science functions to support the development of research that seeks to continually improve outcomes for children and adolescents with cancer.

Tendências da morbimortalidade por câncer infantojuvenil em um polo de fruticultura irrigada

Resumo Objetivo Descrever as tendências de morbimortalidade por câncer em jovens de 0 a 19 anos nos municípios de Petrolina (PE) e Juazeiro (BA). Método Série histórica de morbimortalidade por câncer infantojuvenil dos residentes em Petrolina (PE) e Juazeiro (BA), no período de 2004 a 2013, usando dados do Sistema de Informação de Internação Hospitalar e Sistema de Informação de Mortalidade. As taxas de internação e mortalidade foram padronizadas por idade, tendo sido realizada análise de tendências pelo modelo de regressão Joinpoint. Resultados As taxas de internação e de mortalidade foram mais altas em Petrolina comparadas com as de Juazeiro. Taxas de mortalidade acima de 60/1.000.0000 em ambos os municípios encontram-se acima das taxas de mortalidade brasileiras (40,28/1.000.000) e das taxas de mortalidade do Nordeste (35,62/1.000.000) para o período de 2001 a 2005. Conclusão Houve tendência de aumento significante das taxas de internação e aumento sem significância estatística das taxas de mortalidade nos dois municípios, o que pode estar relacionado à melhoria no acesso ao serviço especializado de oncologia pediátrica, ao diagnóstico tardio e à exposição ambiental a agrotóxicos.

Characteristics and trends in incidence of childhood cancer in Beijing, China, 2000-2009

OBJECTIVE

To investigate the characteristics and incidence trends of childhood cancer in Beijing, China, from 2000 to 2009.

METHODS

A total of 1,274 cases with childhood cancer in Beijing from 2000 to 2009 were included in the study. All rates were age-standardized using the direct method to the world standard population and expressed per million person-years. Incidence trends were characterized by calculating annual percent change (APC) using Joinpoint Regression Program.

RESULTS

The crude incidence rate was 106.47 per million [age-standardized rate (ASR) 113.34] between 2000 and 2009 in Beijing with the most common diagnoses, leukemia (N=505, 39.64%, ASR 45.20), followed by central nervous system (CNS) tumors (N=228, 17.90%, ASR 19.28) and lymphoma (N=91, 7.14%, ASR 6.97). The incidence for all childhood cancers combined has increased during the study period, with an APC of 5.84% [95% confidence interval (95% CI): 1.0-10.9] after adjusted by world population. The ASR of all combined cancers in boys showed a slight, but no significant increase, with an APC of 5.33% (95% CI: -0.6-11.6); for girls, the trends increased significantly, with an APC of 6.54% (95% CI: 1.5-11.8).

CONCLUSIONS

The incidence rate of childhood cancer in Beijing was higher than the average level of China and lower than that of western countries. The incidence trends of childhood cancer, especially leukemia among girls showed a significantly increase from 2000 to 2009. While among boys, no substantially change was seen during the observed time period. Some sex-specific trends by subcategories and trends of major cancers in different age groups by cancer site merit further investigation.

Using a Bayesian hierarchical model for identifying single nucleotide polymorphisms associated with childhood acute lymphoblastic leukemia risk in case-parent triads

Childhood acute lymphoblastic leukemia (ALL) is a condition that arises from complex etiologies. The absence of consistent environmental risk factors and the presence of modest familial associations suggest ALL is a complex trait with an underlying genetic component. The identification of genetic factors associated with disease is complicated by complex genetic covariance structures and multiple testing issues. Both issues can be resolved with appropriate Bayesian variable selection methods. The present study was undertaken to extend our hierarchical Bayesian model for case-parent triads to incorporate single nucleotide polymorphisms (SNPs) and incorporate the biological grouping of SNPs within genes. Based on previous evidence that genetic variation in the folate metabolic pathway influences ALL risk, we evaluated 128 tagging SNPs in 16 folate metabolic genes among 118 ALL case-parent triads recruited from the Texas Children’s Cancer Center (Houston, TX) between 2003 and 2010. We used stochastic search gene suggestion (SSGS) in hierarchical Bayesian models to evaluate the association between folate metabolic SNPs and ALL. Using Bayes factors among these variants in childhood ALL case-parent triads, two SNPs were identified with a Bayes factor greater than 1. There was evidence that the minor alleles of NOS3 rs3918186 (OR = 2.16; 95% CI: 1.51-3.15) and SLC19A1 rs1051266 (OR = 2.07; 95% CI: 1.25-3.46) were positively associated with childhood ALL. Our findings are suggestive of the role of inherited genetic variation in the folate metabolic pathway on childhood ALL risk, and they also suggest the utility of Bayesian variable selection methods in the context of case-parent triads for evaluating the role of SNPs on disease risk.