The Impact of Socioeconomic Status (SES) on Cognitive Outcomes Following Radiotherapy for Pediatric Brain Tumors: A Prospective, Longitudinal Trial.

BACKGROUND Socioeconomic status (SES) is a determinant of cognitive and academic functioning among healthy and ill children; however, few pediatric oncology studies examine SES and long-term cognitive functioning. The current study systematically investigated SES as a predictor of cognitive outcomes among children treated for localized brain tumors (BT) with photon radiation therapy (RT). METHODS 248 children treated on a prospective, longitudinal, phase II trial of conformal RT (54-59.4Gy) for ependymoma, low grade glioma, or craniopharyngioma were monitored serially with cognitive assessments (IQ, reading, math, attention, adaptive function) for ten years (2,209 observations, median age at RT=6.6 years, 48% male, 80% Caucasian). SES was derived from the Barratt Simplified Measure of Social Status, which incorporates parental occupation, education, and marital status. RESULTS Overall, SES scores fell in the low range (Barratt median= 37). At pre-RT baseline, linear mixed models revealed significant associations between SES and IQ, reading, math, attention, and adaptive function, with higher SES associated with better performance (P<.005). SES predicted change over time in IQ, reading, and math; higher SES was associated with less decline (P<.001). Accounting for sex and age at RT, SES remained predictive of IQ, reading and math. Analysis of variance revealed a greater relative contribution of SES than sex or age at RT to reading and math. CONCLUSIONS SES represents a novel predictor of cognitive performance before and after RT for pediatric BT. These findings have broad implications as high SES represents a protective factor. Developing interventions to mitigate effects of low SES is warranted.