Survival for the most common childhood cancer – acute lymphoblastic leukemia (ALL) – is nearly 95%. The chemotherapy drug methotrexate has played a key role in that high cure rate.
St. Jude Children’s Research Hospital researchers found that long-term survivors exposed to high levels of the drug were more likely to struggle with skills like mental flexibility, planning and organization. These skills are needed to multitask and get things done.
Higher blood levels of the drug were also linked to changes in brain function and structure. The changes took place in parts of the brain that affect skills such as reasoning and mental flexibility.
“As childhood cancer survivorship has grown, so has research to understand and reduce the side effects patients experience during and sometimes long after treatment,” said Kevin Krull, PhD, of the St. Jude Department of Epidemiology and Cancer Control.
“This study is the first to show a clear effect between methotrexate concentrations in patients’ blood during treatment and executive functioning in survivors,” he said. “The information will help scientists design ways to reduce that risk.”
The study included 218 long-term ALL survivors. All were treated between 2000 and 2010. The survivors received chemo to the fluid around their brains and spines. This therapy was designed to prevent cancer from coming back in the central nervous system.
The research appeared in the Journal of Clinical Oncology.