Socioeconomic status as a possible moderator of neurocognitive outcomes in children with cancer

Survival rates for childhood cancer have improved markedly; however, there are disparities in outcomes for children from lower socioeconomic status (SES) and/or racial and ethnic minorities. Environmental factors such as reduced access to appropriate care, decreased understanding of the child’s medical needs, and reduced adherence to medical regimens are thought to contribute to the association of low SES and increased mortality rates [1]. Low SES children comparatively are also at increased risk for psychosocial morbidities following cancer, including decreased social and educational functioning [2] and poor mental health-related quality of life (HRQOL) [3]. Differences in SES are known to influence children’s neurocognitive and behavioral development in the general population, where school and home variables such as home literacy and quality of early education are some of the probable pathways [4] but have rarely been the primary focus of investigation in children with cancer. Children who have survived cancers involving the central nervous system (CNS) or who received cancer therapies that can damage the developing brain are at risk of developing long-term neurocognitive impairments. Survivors of acute lymphoblastic leukemia (ALL) and brain tumors are especially susceptible to these adverse neurocognitive effects, which typically emerge within 2 years following treatment completion. The degree of deficit, however, differs in magnitude based on a number of diseases, treatments, and individual factors, of which individual factors are the least known. Recently, it has been speculated that sociodemographic factors such as SES, including parent education and cultural factors, may contribute toward the trajectory of cognitive and behavioral development in these high risk groups [5]. Essentially, SES represents differences in factors such as home environment, parents’ ability to advocate and meet the increased educational needs of their ill child, and the availability and quality of school and neighborhood resources, all of which conceptually facilitate rehabilitation and ongoing compensation for any adverse neurocognitive impact following cancer. Within this context, it seems plausible that SES may possibly moderate the impact of cancer diagnosis and its treatment on neurocognitive and behavioral outcomes, perhaps under certain circumstances. In our prior work, which examined associations of parenting factors with IQ outcomes in childhood cancer survivors, findings suggested that environmental factors (e.g., parent involvement) may be influential if the brain injury is to a less severe degree [6]. A few studies have now observed that SES is a strong predictor of cognitive functioning in survivors of childhood cancer that involved CNS disease and/or treatment [7]; however, the majority has not examined it as a potential moderator of differential outcomes. Only one study has investigated SES in relation to longitudinal neurocognitive change. In their prospective study of neurocognitive functioning in children treated with craniospinal irradiation for medulloblastoma brain tumor, Palmer et al. (2013) observed that higher parent education was associated with higher neurocognitive functioning at baseline but that it was not associated with change in performance across time [8]. Similar investigations have not been conducted in survivors of ALL, where long-term neurocognitive outcomes theoretically could be viewed as more susceptible to