Feasibility of neonatal dried blood spot retrieval amid evolving state policies (2009-2010): a Children's Oncology Group study

Children's Oncology Group's 2023 blueprint for research: Epidemiology

The Children's Oncology Group (COG) Epidemiology Committee has a primary focus on better understanding the etiologies of childhood cancers. Over the past 10 years, the committee has leveraged the Childhood Cancer Research Network, and now more recently Project:EveryChild (PEC), to conduct epidemiologic assessments of various childhood cancers, including osteosarcoma, neuroblastoma, germ cell tumors, Ewing sarcoma, rhabdomyosarcoma, and Langerhans cell histiocytosis. More recent studies have utilized questionnaire data collected as part of PEC to focus on specific characteristics and/or features, including the presence of congenital disorders and the availability of stored cord blood. Members of the COG Epidemiology Committee have also been involved in other large-scale National Institutes of Health efforts, including the Childhood Cancer Data Initiative and the Gabriella Miller Kids First Pediatric Research Program, which are improving our understanding of the factors associated with childhood cancer risk. Future plans will focus on addressing questions surrounding health disparities, utilizing novel biospecimens in COG epidemiology studies, exploring the role of environmental factors on the etiologies and outcomes of childhood cancer, collaborating with other COG committees to expand the role of epidemiology in childhood cancer research, and building new epidemiologic studies from the Molecular Characterization Initiative-all with the ultimate goal of developing novel prevention and intervention strategies for childhood cancer.

Operationalization of assent for research participation in pre-adolescent children: a scoping review

BACKGROUND

Seeking assent from children for participation in medical research is an ethical imperative of numerous institutions globally. However, none of these organizations provide specific guidance on the criteria or process to be used when obtaining assent. The primary objective of this scoping review was to determine the descriptions of assent discussed in the literature and the reported criteria used for seeking assent for research participation in pre-adolescent children.

METHODS

Medline and Embase databases were searched until November 2020 using the term "assent" in the title or abstract. Inclusion criteria were (1) studies enrolling children which specifically described operationalization of the assent process and (2) studies of the assent process which provided a description of assent. Data collected included participant information, patient criteria for seeking assent, guidelines referenced, description of assent reported, how assent was obtained and assent information presented, and reported assent rate. For qualitative articles focusing on the assent process, important themes were identified.

RESULTS

A total of 116 articles were included of which 79 (68.9%) operationalized assent and 57 studies (%) described the assent process. The most commonly reported criterion used to determine the ability of a child to assent was age (35.4%, 28/79). The reported minimal age for obtaining pediatric assent varied considerably across and within jurisdictions (5-13 years; median 7.5 years, IQR 7.0, 9.75). Cognitive ability was reported as a criterion for obtaining assent in 5.1% (4/79) of studies. Assent rates were only reported in 17.7% (14/79) of citations and ranged from 32.0 to 100%. Analysis of the 57 studies describing the assent process identified several themes, including age thresholds, assessment of capacity, variable knowledge of pediatric assent and parental roles.

CONCLUSION

We found significant variation in criteria used for assessment of patient capacity, delivery of information used to obtain assent and documentation of the assent process. While we acknowledge that individual children, settings and jurisdictions may require different approaches to obtaining assent, there should be agreement on important principles to be followed with resulting common guidance on assessing capacity, delivering information and documentation of the assent process for publication.

Factors associated with maternal consent for use of residual newborn bloodspots in the National Birth Defects Prevention Study

PURPOSE

We investigated factors associated with maternal consent to use residual newborn dried bloodspots (DBS) in a national case-control study of birth defects.

METHODS

A subset of sites in the National Birth Defects Prevention Study (NBDPS; 1997-2011) asked participants to provide consent for investigators to retrieve DBS from local newborn screening programs to use for research on risk factors for birth defects. We assessed whether consent differed by factors including maternal age, education, parity, body mass index, language of interview, country of birth, and case-control status.

RESULTS

Of 5,850 mothers of cases and 2,534 mothers of controls, 57% provided consent for the DBS component. Mothers of cases were more likely to participate than mothers of controls (61% vs. 52%), as were mothers who self-reported white race, >12 years of education, and born in the United States.

CONCLUSIONS

Retrieval of DBS can be integrated into retrospective studies of neonatal outcomes including birth defects. In NBDPS, participation in the DBS component was moderate and varied by some sociodemographic factors. Further research is needed to better understand families' perspectives on using residual DBS for secondary research. Representative participation is important to reduce the potential for selection bias in future studies using DBS for children's health research.

Using primary teeth and archived dried spots for exposomic studies in children: Exploring new paths in the environmental epidemiology of pediatric cancer

It is estimated that 300,000 children 0-14 years of age are diagnosed with cancer worldwide each year. While the absolute risk of cancer in children is low, it is the leading cause of death due to disease in children in high-income countries. In spite of this, the etiologies of pediatric cancer are largely unknown. Environmental exposures have long been thought to play an etiologic role. However, to date, there are few well-established environmental risk factors for pediatric malignancies, likely due to technical barriers in collecting biological samples prospectively in pediatric populations for direct measurements. In this review, we propose the use of novel or underutilized biospecimens (dried blood spots and teeth) and molecular approaches for exposure assessment (epigenetics, metabolomics, and somatic mutational profiles). Future epidemiologic studies of pediatric cancer should incorporate novel exposure assessment methodologies, data on molecular features of tumors, and a more complete assessment of gene-environment interactions.

The Prenatal Origin of Childhood Leukemia: Potential Applications for Epidemiology and Newborn Screening

Childhood leukemias are heterogeneous diseases with widely differing incident rates worldwide. As circulating tumors, childhood acute leukemias are uniquely accessible, and their natural history has been described in greater detail than for solid tumors. For several decades, it has been apparent that most cases of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) initiate in utero. Circumstantial evidence in support of this contention includes the young age of onset and high rate of concordance among identical twins. "Backtracking" of leukemic somatic mutations, particularly gene translocations, to cord blood and dried blood spots collected during the perinatal period has provided molecular proof of prenatal leukemogenesis. Detection of a patient's leukemia translocation in easily accessible birth samples, such as dried blood spots, is straightforward with the knowledge of their idiosyncratic breakpoints. However, to translate these findings into population-based screening and leukemia prevention requires novel methods able to detect translocations at all possible breakpoints when present in a low frequency of cells. Several studies have attempted to screen for leukemic translocations, mainly the common ETV6-RUNX1 translocation, in cord blood samples from healthy children. Most studies have reported finding translocations in healthy children, but estimates of prevalence have varied widely and greatly exceed the incidence of leukemia, leading to concerns that technical artifact or contamination produced an artificially inflated estimate of translocation prevalence at birth. New generation techniques that capture the presence of these translocations at birth have the potential to vastly increase our understanding of the epidemiology of acute leukemias. For instance, if leukemic translocations are present at birth in a far higher proportion of children than eventually develop acute leukemia, what are the exposures and somatic molecular events that lead to disease? And could children with translocations present at birth be targeted for prevention of disease? These questions must be answered before large-scale newborn screening for leukemia can occur as a public health initiative. Here, we review the literature regarding backtracking of acute leukemias and the prevalence of leukemic translocations at birth. We further suggest an agenda for epidemiologic research using new tools for population screening of leukemic translocations.

Eliciting parental support for the use of newborn blood spots for pediatric research

Background

Biomarkers of exposures such as infection or environmental chemicals can be measured in small volumes of blood extracted from newborn dried blood spots (DBS) underscoring their potential utility for population-based research. However, few studies have evaluated the feasibility and utility of this resource; particularly the factors associated with parental consent, and the ability to retrieve banked samples with sufficient remaining volume for epidemiologic research.

Methods

At 8 months postpartum, 5,034 mothers of infants born (2008–2010) in New York (57 counties excluding New York City) were asked to consent for the use of residual DBS for the quantification of cytokines and environmental chemicals. Mothers were part of the Upstate KIDS study, a longitudinal birth cohort designed to evaluate child development through 3 years of age. Information on parental and infant characteristics was obtained from birth certificates and maternal report at 4 months postpartum. Multivariate logistic regression was used to identify factors associated with parental consent and with successful retrieval of DBS.

Results

Sixty-two percent (n = 3125) of parents consented. Factors significantly associated with consent included non-Hispanic ethnicity (odds ratio 2.04; 95 % CI: 1.43–2.94), parity (1.29; 1.05–1.57), maternal obesity (1.42; 1.11–1.80) and reported alcohol use during pregnancy (1.51; 1.12–2.06). However, these associations corresponded to small absolute differences in proportions (4 to 8 %), suggesting that the two groups remained comparable. Infant characteristics such as preterm delivery did not significantly differ by consent status among singletons and only ventilator use (OR 2.39; 95 % CI: 1.06–5.41) remained borderline significant among twins in adjusted analyses. Among consented infants, 99 % had at least one 3.2 mm punch successfully retrieved for biomarker analyses and 84 % had a full DBS circle available.

Conclusion

Parental characteristics varied slightly by consent, and the availability of samples for research purposes was high, demonstrating the feasibility of this resource for population based research.

When Children Become Adults: Should Biobanks Re-Contact?

Noor Giesbertz and colleagues consider different re-contact policy designs that could be used by biobanks to obtain permission for the continued use of samples collected from children.

Return of Results from Research Using Newborn Screening Dried Blood Samples

There may be compelling reasons to return to parents a limited subset of results from research conducted using residual newborn screening dried blood samples (DBS). This article explores the circumstances under which research results might be returned, as well as the mechanisms by which state newborn screening programs might facilitate the return of research results. The scope of any responsibility to return results of research conducted using DBS should be assessed in light of the potential impact on the primary mission of state newborn screening programs.

Attitudes of parents of children with serious health conditions regarding residual bloodspot use

BACKGROUND/OBJECTIVES

Studies have shown that the general public is supportive of newborn screening (NBS) and supportive of the storage and use of residual bloodspots for quality assurance and biomedical research. However, the attitudes of parents of children with serious health conditions have not been assessed. In this study, we assessed attitudes of parents with children who have phenylketonuria (PKU) and leukemia towards NBS and storage and use of residual bloodspots for research.

METHODS

A total of 49 individuals were recruited and responded to a validated 41-item survey regarding NBS and the retention and use of residual bloodspots. Of these participants, 22 had a child with PKU and 27 had a child with leukemia. We compared their responses to those of 1,927 individuals from the general public obtained in a previous study using the same survey instrument.

RESULTS/CONCLUSIONS

We found that parents of children with a serious health condition had higher levels of support than the general public towards the use of residual NBS samples for research but similar attitudes regarding choice and privacy protections. It is important to assess the attitudes of various stakeholders for policy development.

Long-term stability of folate in dried blood spots stored in several conditions

We examined stability of folate in 50 subjects’ dried cord blood spots stored for 9 months at −80 °C, 4 °C, ambient and humid conditions. Mean folate declined progressively, but most subjects were +/− 3 ranks of their −80 °C position. Meaningful information about relative concentrations was retained across conditions.

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

Investigators worldwide have for over 40 years conducted case-control studies aimed at determining the causes of childhood cancer. The central challenge to conducting such research is the rarity of childhood cancer, thus many studies aggregate cases through clinical trials organizations such as COG. Rarity also precludes the use of prospective study designs, which are less prone to recall and selection biases. Despite these challenges a substantial literature on childhood cancer etiology has emerged but few strong environmental risk factors have been identified. Genetic studies are thus now coming to the fore with some success. The ultimate aim of epidemiologic studies is to reduce the population burden of childhood cancer by suggesting preventive measures or possibly by enabling early detection. Pediatr Blood Cancer 2013; 60: 1059-1062. © 2012 Wiley Periodicals, Inc.

Research results: preserving newborn blood samples

Retention and use, without explicit parental permission, of residual dried blood samples from newborn screening has generated public controversy over concerns about violations of family privacy rights and loss of parental autonomy. The public debate about this issue has included little discussion about the destruction of a potentially valuable public resource that can be used for research that may yield improvements in public health. The research community must advocate for policies and infrastructure that promote retention of residual dried blood samples and their use in biomedical research.