Impact of treatment exposures and socioeconomic status on neurocognitive performance in children with brain tumors

Abstract PURPOSE To investigate the impact of treatment exposures and socioeconomic status on neurocognitive performance in children with brain tumors. METHODS Eligible patients included those diagnosed with a brain tumor at <22 years of age with ≥ 1 neurocognitive assessment. Neurocognitive impairment was defined as performance 1.5 standard deviations below the normative mean using age standardized measures of intellectual function. Neurocognitive outcomes included Wechsler indices of full-scale intelligent quotient (IQ), working memory (WM), and processing speed (PS). Neurocognitive decline was defined as a negative slope. Logistic regression identified variables associated with neurocognitive impairment. Longitudinal data was analyzed using linear mixed models. RESULTS Eligible patients (n=152) had a mean neurocognitive follow-up of 50.2 months and median age at diagnosis of 9.6 years. PS was most frequently impaired in patients (37.5%) followed by IQ (20.6%) and WM (16.5%). Patients with public insurance had eight-fold increased odds of impaired IQ compared to those with private insurance (Odds Ratio [OR]: 7.59, p<0.001). Patients treated with CSI had eight-fold increased odds of impaired IQ (OR: 7.86, p=0.003) and almost six-fold increased odds of impaired WM (OR: 5.66, p=0.028) compared to those treated without RT. After accounting for age, change in IQ was associated with chemotherapy use (slope: -0.45 points/year with chemotherapy vs. 0.71 points/year without chemotherapy, p=0.012). Patients treated with both chemotherapy and RT demonstrated the greatest decline whereas those treated without either demonstrated no decline in any of the neurocognitive measures. CONCLUSION After treatment for pediatric brain tumors, public insurance, an indicator of low socioeconomic status, was associated with impairment in IQ with a large effect size similar to that of CSI. Chemotherapy was associated with decline in IQ with a small effect size. Combined chemotherapy and RT had additive effects on neurocognitive decline in IQ, WM, and PS.