Multidisciplinary treatment of malignant pediatric brain tumors

Abstract

Brain tumors are the second most prevalent cancers in children (after leukemia) and remain the leading cause of cancer-related mortality in childhood. Treating children with brain tumors begins with an absolute requirement for the correct diagnosis, accurate staging of the extent of the disease and determination of the prognostic subgroup. Throughout treatment, every child with brain tumor should have the benefit of an expert pediatric cancer care team. The Japanese Ministry of Health, Labor and Welfare designated 15 hub hospitals to administer such comprehensive pediatric cancer care in 2013. Medulloblastoma is the most common malignant childhood brain tumor. Overall survival rates for patients with medulloblastoma have reached 70~80% using treatment protocols that include a combination of surgery, cranio-spinal radiotherapy (in children ≥3 years of age) and chemotherapy. Current risk stratification tools are solely based on clinical features, including age at diagnosis, extent of surgical resection, metastatic status. Molecular subclassification is rapidly informing the clinical management of medulloblastoma. These findings are currently making their way into risk-adapted treatment. Molecular characterization approaches have also yielded insights into new therapeutic targets. Current management of ependymoma includes surgical resection followed by adjuvant radiotherapy. Children are especially difficult to manage because they often experience multiple recurrences. Numerous studies have shown that ependymoma is still a surgical disease. Recent advances in molecular studies have found that ependymomas have unique molecular signatures with distinct gene expression patterns, chromosomal changes, and protein expression. Through an improved understanding of the molecular and genetic basis of ependymoma, it is anticipated that patients will be risk-stratified and treated in the future. The recent designation of pediatric cancer hub hospitals and molecular characterization approaches will hopefully lead to improved patient outcomes with reduced sequelae.