Oxidative stress and executive function in children receiving chemotherapy for acute lymphoblastic leukemia

Neurocognitive sequelae following treatment for pediatric acute lymphoblastic leukemia (ALL) has been reported in a significant proportion of survivors, including those treated only with chemotherapy. Early identification of children "at risk" for neurocognitive problems is not yet reliable. Biomarkers of oxidative stress (e.g., oxidated phosphatidylcholine) in cerebral spinal fluid (CSF) have been correlated with intensity of methotrexate (MTX) treatment, suggesting an association with acute central nervous system toxicity.

This study examined the association between oxidized CSF phospholipids and executive functions throughout chemotherapy. Measures of oxidative stress and executive functions were examined in 88 children newly diagnosed with ALL. The children were followed over 3 years with neurocognitive testing and parent ratings of executive functions.

Results demonstrated an association between increased oxidative stress following induction and consolidation and decreased executive function 2 years later. Younger age at diagnosis was associated with both an increase in oxidative stress and in executive dysfunction; younger age was associated with poorer ability to organize materials in one's environment (r(48) = 0.28, P < 0.05) and with greater oxidated phosphatidylcholine in CSF at the end of chemotherapy (r(48) = -0.27, P < 0.05). As such, younger age appears to be the most prominent moderator of neurocognitive decline.

These results link functional changes to CSF biomarkers and underscore the importance of monitoring cognitive development in young children treated for ALL. Children with less advanced central nervous system development may be particularly vulnerable to the effects of chemotherapy.