Cognitive status of children treated with central nervous system prophylactic chemotherapy for acute lymphocytic leukemia.

Treatment-related cognitive impairments have been reported for survivors of childhood leukemia following prophylactic central nervous system (CNS) treatment with craniospinal radiation. We examined the neurocognitive status of 46 children with acute lymphocytic leukemia (ALL) to assess the impact of a regimen consisting of systemic chemotherapy and prophylactic CNS chemotherapy. By comparing three groups of ALL children (i.e., patients whose diagnosis was recent, patients 1 year postdiagnosis currently receiving CNS prophylactic chemotherapy, and off-therapy patients who had been treated with chemotherapy for 3 years) and their healthy siblings on measures of sequential and simultaneous processing, we were able to examine the effects of CNS prophylactic and systemic chemotherapy at various points during treatment. Results indicate that the children who had received a 3-year course of chemotherapy (off-therapy patients) were more impaired on tasks involving right-hemisphere simultaneous processing than were sibling controls or ALL children whose diagnosis was recent and whose treatment had just begun. Age at diagnosis did not interact with the effects of chemotherapy. These findings support the need for continued evaluation of cognitive functioning in ALL, children receiving CNS prophylactic chemotherapy to identify potential harmful neurocognitive sequelae of treatment.