Predictors of Cognitive Performance Among Infants Treated for Brain Tumors: Findings From a Multisite, Prospective, Longitudinal Trial

Abstract

PURPOSE Infants treated for CNS malignancies experience a significantly poorer response to treatment and are particularly at risk for neuropsychological deficits. The literature is limited and inconsistent regarding cognitive outcomes among this group. We investigated predictors of cognitive outcomes in children treated for brain tumors during infancy as part of a large, prospective, multisite, longitudinal trial. PATIENTS AND METHODS One hundred thirty-nine infants with a newly diagnosed CNS tumor were treated with chemotherapy, with or without focal proton or photon radiation therapy (RT). Cognitive assessments were conducted at baseline, 6 months, 1 year, and then annually for 5 years. The median length of follow-up was 816 days (26.8 months). Neurocognitive testing included assessment of intellectual functioning (intellectual quotient [IQ]), parent ratings of executive functioning and emotional and behavioral functioning, and socioeconomic status. RESULTS At baseline, IQ, parent-reported working memory, and parent-reported adaptive functioning were worse than normative expectations. Baseline cognitive difficulties were associated with younger age at diagnosis and lower socioeconomic status. Linear mixed models did not demonstrate a decline in IQ over time. There were increased parent-reported attention and executive problems over time. Increased concerns were related to supratentorial tumor location and CSF diversion. There were no differences in cognitive outcomes based on treatment exposure (chemotherapy-only v chemotherapy with RT and proton v photon focal RT). CONCLUSION Even before adjuvant therapy, young children with brain tumors experience cognitive difficulties that can affect quality of life. Changes in cognitive functioning over time were dependent on tumor location and surgical factors rather than adjuvant therapy. These findings may serve to guide treatment planning and indicate targets for cognitive monitoring and intervention.