Approximately 25% of all pediatric cancers are in the brain, and they are the most common solid tumors found in children. As with survivors of other types of cancer, these young cancer patients are surviving longer, thanks to improved diagnostic techniques and advances in treatment. Many of these patients have seizures, which are the presenting symptom in approximately 10% of children with brain tumors.1
Children who are long-term survivors of brain cancer may suffer from seizure activity for years, since it often begins before diagnosis and can continue far into treatment and beyond. And therein lies the question: Although clinicians expect to see seizures in pediatric patients who have primary brain tumors, for how long a period can they occur? Should the oncology nurse expect to see seizures in these children even years after treatment?
Nicole J. Ullrich, MD, is director of neurologic neuro-oncology at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, in Boston, Massachusetts. She and her colleagues undertook a study of seizures among patients with pediatric brain tumor. The Boston group’s objective was to evaluate and describe the incidence and risk factors for seizures among children who have been treated for brain tumors and who went on to become long-term survivors. They also wanted to identify factors that could predict negative seizure outcomes.
The retrospective, longitudinal study took place over a period of 12 months.1 The investigators evaluated all children who presented for follow-up to the Pediatric Brain Tumor Program Outcomes Program at Dana-Farber. In order to qualify, patients had to have received a diagnosis of primary brain tumor with at least one unequivocal witnessed seizure. They also had to undergo follow-up at Dana-Farber. Children were seen 2 or more years after their CNS tumors were first diagnosed. The data were readily available because Dana-Farber follows primary brain tumor survivors for a minimum of 10 years after the end of their treatment. Patients undergo neuroimaging studies every 3 months for the first follow-up year, every 6 months for the second year of follow-up, and then every year after that. Once they have attained a 10-year posttreatment period, patients then can progress to undergoing neuroimaging studies every 2 years.1
This study included 298 patients, 140 were female.1 The average age at diagnosis was 7.62 years. The mean duration of follow-up after their initial diagnosis was 7.54 years. The most common tumors presented were low-grade gliomas and glial-neuronal tumors, medulloblastoma, and ependymoma. Of the 298 patients, 143 had subtotal resections and 109 had total resections. Chemotherapy was administered to 127 patients, 186 patients underwent cranial radiation therapy, and 86 children received both interventions. The tumors recurred in 92 (30%) patients.1