Socioeconomics, race, and ethnicity in childhood cancer survival: Accessing and addressing root causes of disparities

Abstract

In this issue of Cancer, Kehm et al 1 report on racial and ethnic differences in childhood cancer survival and quantify how socioeconomic status (SES) mediates these disparities. They show that SES accounts for 28% to 73% of racial and ethnic disparities for several childhood cancers, including acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), neuroblastoma, and non-Hodgkin lymphoma. In addition, the authors note that there are still statistically significant racial and ethnic disparities in survival independent of SES, the sources of which remain unclear. Both of these statements represent important steps in the understanding of childhood cancer disparities; they are at once calls for further work to improve our understanding of inequalities as well as opportunities to address them. In this editorial, we explore the epidemiologic challenges of understanding social determinants of childhood cancer survival, specifically those concerning racial and ethnic disparities, and we discuss future directions for increasing health equity for childhood cancer patients.There is resounding evidence that social factors, including race, ethnicity, and SES, are associated with disparities in cancer survival. 2,3 The current study makes important progress in deconvoluting these different factors while also highlighting the challenges of these efforts. Large databases such as the Surveillance, Epidemiology, and End Results (SEER) database provide powerful evidence that is widely generalizable and not prone to selection and survival biases. 4,5 Compared with clinical trials, this population-based study provides a better opportunity for understanding possible differences in racial and ethnic populations, which are often underrepresented in clinical trials. 4,6 However, there are some distinct limitations to consider with the SES classification in the SEER database. Because it is an ecological variable rather than an individual-level determination, there may be significant measurement error or misclassification of individuals, which may bias the socioeconomic effect toward the null 7,8 ; therefore, its contribution to disparities may be underestimated. Because individuals are uniformly labeled, variations in education, income, and occupation within the area-based grouping will not be detectable. The individuals who are worst off and in turn may have the worst survival outcomes will not be identified. Previous research has shown large variability between area-based and household incomes. 9 Consortium trials may provide a balance between collecting individual data and being widely generalizable, but requiring access to advanced centers may limit the generalizability to geographically or economically isolated populations. Furthermore, with the adjustment of the SES status, there is the risk of residual confounding stemming from the broadness of the SES grouping parameters and errors in the classification of SES grouping. 10 A more comprehensive analysis of health insurance status, rather than the crude measure used in th...

Associations Between Race/Ethnicity and US Childhood and Adolescent Cancer Survival by Treatment Amenability

“…Understanding whether stage at diagnosis explains some of the racial/ethnic disparities in childhood cancer survival is an important area of future investigation. Fourth, our variables for income and educational level were obtained at the county level vs the individual level, which could result in misclassification 36 and incomplete adjustment for socioeconomic status. Models adjusting for insurance status-a variable obtained at the individual level-may provide better adjustment for socioeconomic status.…”

Minority children experience a higher risk of death from many central nervous system tumor types even after accounting for treatment received: A National Cancer Database analysis

“…5 Often times, racial/ethnic survival disparities are explained by or linked to existing differences in socioeconomic status. 6 However, in a mediation analysis examining the role of socioeconomic status between race/ethnicity and survival from childhood cancers, 7 most of the observed associations were only minimally explained by, or were largely independent of, socioeconomic status, and strong direct effects of race/ethnicity were observed. This suggests that genomics, treatment receipt, or treatment response differences may underlie the observed disparities.…”

“…Minority children are less frequently diagnosed with these tumors as White children have an incidence rate of 5 cases per 100,000 and Black and Hispanic children have a rate of 4 cases per 100,000 2 ; however, Black and Hispanic children experience an increased risk of death in comparison with White children 3,4 even after accounting for age, socioeconomic status, stage of disease, and treatment as adjustment factors in the analysis 5 . Often times, racial/ethnic survival disparities are explained by or linked to existing differences in socioeconomic status 6 . However, in a mediation analysis examining the role of socioeconomic status between race/ethnicity and survival from childhood cancers, 7 most of the observed associations were only minimally explained by, or were largely independent of, socioeconomic status, and strong direct effects of race/ethnicity were observed.…”

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

“…For instance, Hispanic children tend be older than their non-Hispanic White peers at diagnosis [8] and display a different distribution of cytogenetic features, such as reduced frequency of favorable ETV6-RUNX1 fusion and increased frequency of unfavorable CRLF2 rearrangement, which likely contribute to poorer prognosis [9][10][11]. However, ethnic disparities may also be influenced by factors such as the high prevalence of obesity among Hispanic children [12,13], disproportionate difficulty managing the financial burden of a childhood cancer diagnosis among ethnic minority and/or socioeconomically disadvantaged families [14,15], differential access or adherence to care [16,17], and under-representation in clinical trials [18,19]. In addition to these individual factors, neighborhood socioeconomic deprivation is associated with inferior survival among children with ALL [20][21][22][23].…”