Neuropsychological effects of childhood cancer treatment

The potential neuropsychological effects of treatment were investigated in 124 childhood cancer patients. Children were classified into groups on the basis of treatment modality and treatment status. All patients received systemic chemotherapy. Other treatment modalities included intrathecal chemotherapy and intrathecal chemotherapy plus central nervous system radiation therapy. Treatment status was determined by whether children were newly diagnosed patients in active treatment or long-term survivors of cancer. This classification resulted in five groups; group 1 (n = 29)--children with newly diagnosed disease who were receiving intrathecal chemotherapy; group 2 (n = 21)--children with newly diagnosed disease who were receiving systemic chemotherapy without central nervous system treatment; group 3 (n = 24)--long-term survivors who had received intrathecal chemotherapy; group 4 (n = 25)--long-term survivors who had received intrathecal chemotherapy plus cranial radiotherapy; and group 5 (n = 25)--long-term survivors who had received systemic chemotherapy only (no specific central nervous system treatment). Groups were compared by using multivariate analysis of variance on sets of neuropsychological test variables that represent major cognitive domains. Results of comparisons indicated significant group differences for most dependent-variable sets. Follow-up pairwise comparisons showed that the group of long-term survivors who had received intrathecal chemotherapy plus cranial radiotherapy consistently obtained lower test scores than the other four groups. These findings are consistent with results of previous studies, thus indicating that intrathecal chemotherapy plus cranial radiotherapy is associated with significant effects on neuropsychological performance. Comparisons among newly diagnosed and long-term groups of patients who did not receive cranial radiotherapy yielded null results on measures of higher-order cognitive functions. However, significant group differences were observed on measures of fine-motor and visual-motor skills; newly diagnosed groups obtained lower scores than the nonirradiated long-term survivor groups. Findings were attributed to chemotherapy-induced peripheral neuropathy that differentially affected the newly diagnosed groups.