Pediatric acute lymphoblastic leukemia (ALL) patients treated with chemotherapy alone are at risk for attention and learning problems that persist after treatment ends, according to a study published in the Journal of Clinical Oncology.
Researchers said this study is the largest assessment to date of neurocognitive outcomes in pediatric ALL survivors treated with intensive chemotherapy alone rather than in combination with cranial radiation.
“This is an important contribution to the literature because the smaller size and design of previous studies made examining the impact of treatment difficult,” said study author Lisa Jacola, PhD, of St. Jude Children’s Research Hospital in Memphis, Tennessee.
“The findings underscore the need for neurocognitive and academic screening to be included as part of routine survivorship care for all pediatric ALL survivors.”
The study included patients enrolled in the St. Jude Total Therapy Study XV. They underwent neurocognitive assessments at the beginning of induction (n=142), end of maintenance (n=243), and 2 years after completing treatment (n=211).
The subjects completed standardized tests of overall intelligence, attention, learning, and academic performance. In addition, parents and other caregivers rated the subjects’ attention, learning, and behavior.
Two years after treatment completion, subjects performed as expected for their age (compared to national data) on measures of overall intelligence, learning, and memory. However, study subjects had significant attention deficits and a significantly greater frequency of learning problems (all P≤0.005).
The risk of such problems was greatest for survivors who were less than 5 years old when diagnosed with ALL and for those who received more intensive chemotherapy.
Specifically, the younger subjects had a greater risk of difficulties with attention, learning, working memory, and processing speed (all P≤0.05). And subjects who received higher-intensity, CNS-directed chemotherapy had a greater risk of difficulties in attention, processing speed, and academics (all P≤0.01).
Researchers also found that subjects with attention problems at the end of therapy had lower academic scores 2 years later (all P≤0.05).
“These findings provide additional evidence that neurocognitive functioning has improved in survivors of childhood ALL since cranial irradiation was replaced with intensified chemotherapy,” Dr Jacola said.
“But we also show these young people are at an elevated risk for attention problems that have real-world consequences, particularly for learning and school performance. Attention is a building block for learning, and, in this study, attention difficulties predicted academic problems later. If we know attention problems seen at the end of therapy continue and contribute to academic problems, then our goal is to intervene earlier to reduce or prevent such difficulties.”
