"Research has found that treatment for acute lymphoblastic leukemia (ALL), the most common cancer among children, may potentially cause cognitive disabilities in long-term survivors after chemotherapy and/or radiation is completed. Patients may often struggle with attention and concentration difficulties, they may experience academic problems in school and occasionally they may even have problems with short-term memory," said Dr. Mehmet Okcu, research director of Texas Children's Cancer Center Long-term Survivor Program.
Okcu, who is also a pediatric oncologist with Texas Children's Cancer Center and assistant professor of pediatrics at Baylor College of Medicine, said that these cognitive disorders have long-ranging consequences for the pediatric cancer survivor. These patients experience difficulty with standardized tests such as the SAT, as well as difficulty getting into college and finding jobs.
This is why Okcu and his research team are extracting DNA from blood samples obtained from long-term survivors – patients who have been off of therapy for at least five years – who are willing to participate in this study. The DNA from the blood samples is studied extensively for specific genetic coding or "markers." This process will allow researchers to identify which markers are present in long-term survivors with cognitive disorders.
The long-term goal is to apply this data to newly diagnosed leukemia patients to determine if they are at risk for developing learning disorders after their treatment is completed. The DNA from blood samples obtained from new patients will be tested to see if they contain the markers present in the long-term survivors who developed cognitive disabilities. If the markers are present, it may be possible to provide early intervention strategies for prevention of learning issues or even consider modifying the course of therapy planned.
"This would allow more flexibility in treatment options for both the patients and the physicians," said Okcu.
Texas Children's Cancer Center is the only pediatric cancer center in the nation to conduct research into what genetic codes may be associated with learning disorders.
"We want to learn everything we can about how we can decrease the possibility of newly diagnosed patients developing these learning disorders so that they can move forward with normal, healthy lives after their cancer treatment," Okcu said.
Cognitive disorders are only one late-effect of pediatric cancer treatment. Patients also can develop other late-effects including heart problems, kidney damage, hearing and vision loss, as well as infertility.
"Because survival rates for pediatric cancers have increased over the last several decades, a more in-depth focus is needed to study the effects of cancer and cancer treatment and how they affect a child's ability to carry on a normal life after cancer," said Okcu.
For more information on Texas Children's Cancer Center and its long-term survivor program, visit www.texaschildrenshospital.org/cancer.