A meta-analysis of the neurocognitive sequelae of treatment for childhood acute lymphocytic leukemia

Background. Impaired neurocognitive functioning is one increasingly recognized long-term consequence of childhood ALL treatment. However, research findings have been inconsistent regarding the domains affected and the degree to which they are compromised. Procedure. A comprehensive meta-analytic review of the long-term neurocognitive effects of childhood ALL was conducted. Studies were included if they were published in English, reported original quantitative data on the post-treatment neurocognitive functioning of childhood ALL patients in first remission and control groups, and used neurocognitive measures with adequate psychometric properties and published normative data. Results. Data from 28 empirical studies yielding 13 effect sizes across nine domains were extracted and analyzed. All effects were negative (g=-0.34 to -0.71), demonstrating that ALL survivors consistently experienced significant deficits in intellectual functioning, academic achievement, and specific neurocognitive abilities compared to control groups. The role of potential moderators, including treatment with cranial irradiation, age at time of diagnosis, and time since treatment ended, was examined. However, no effects emerged as clearly and consistently moderated by these variables. Conclusions. The results from this meta-analysis suggest that declines in both global and specific areas of areas of neurocognitive functioning occur as a result of contemporary ALL treatment. Such deficits have significant implications for survivors' academic achievement and overall quality of life. Neurocognitive assessment plays a critical role in determining what remedial or specialized instruction is needed in childhood ALL survivors and should be included as a standard part of long-term follow-up care.