Childhood Cancer Survivors May Develop Cognitive Problems from Chemotherapy

Issues with learning and paying attention associated with intensive chemotherapy for leukemia.

Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for developing neurocognitive issues from treatment with chemotherapy, according to a recent study.

The study, published in the Journal of Clinical Oncology, administered neurocognitive assessments to patients at the beginning and end of contemporary ALL treatment, as well as 2 years after. While ALL is the most common and curable type of childhood cancer, survivors may face issues later in life with attention and processing speed.

The researchers sought to evaluate neurocognitive functioning 2 years after survivors finished therapy, specifically monitoring any changes that occurred since the therapy was completed.

The results showed that after 2 years, the surviving patient’s measures of overall intelligence, learning, and memory correlated with their appropriate age group. However, there was a higher risk for attention issues, with parents reporting that their child had increased learning difficulties.

Furthermore, there were higher risks for survivors diagnosed when they were less than 5-years-old and for children who underwent more intensive chemotherapy. Patients with attention issues after the completion of chemotherapy were found to have lower academic scores 2 years later.

"These findings provide additional evidence that neurocognitive functioning has improved in survivors of childhood ALL since cranial irradiation was replaced with intensified chemotherapy," said first and corresponding author Lisa Jacola, PhD. "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."

The study participants enrolled in the St. Jude Total XV protocol (2000 to 2007), where they were given standardized tests to determine overall intelligence, attention, learning, and academic performance. Parents and caregivers also rated the attention, learning, and behavior of the study participants.

There were 339 patients eligible for the study, however only 167 completed the process after therapy ended and 2 years after therapy ended. There was no significant difference between survivors who did or did not complete both of the assessments, which researchers believe suggests the results apply to everyone in the study.

"This is an important contribution to the literature because the smaller size and design of previous studies made examining the impact of treatment difficult," Jacola said. "The findings underscore the need for neurocognitive and academic screening to be included as part of routine survivorship care for all pediatric ALL survivors."

Meanwhile, researchers are still looking to explore how brain structure and function is affected by ALL treatments, especially among patients 3- to 5-years-old when they develop the disease.

Although some stimulant medications can improve attention, this option is not always available for cancer patients. Another option would be computer-based interventions designed like video games to help improve working memory and memory difficulties in pediatric survivors.

However, more research needs to be conducted to determine when the right time to intervene would be in order to help prevent and minimize cognitive issues.