Brain tumors in children.

Primary central nervous system tumors are the second most common form of childhood cancer and the leading cancer-related cause of death and illness in children. Developments in neuroscience have led to an increasing understanding of these neoplasms, to alternations in their classification system, and to progress (albeit frustratingly slow progress) in their management. Chemotherapy has become an integral part of the treatment of many forms of childhood brain cancer, including medulloblastoma. Increasing evidence indicates that the amount of craniospinal radiation therapy required for diseases control can be reduced, possibly decreasing treatment-related sequelae, when this therapy is combined with postradiation chemotherapy. The value of the use of preradiation chemotherapy remains unproven. For other types of tumors, such as malignant high-grade gliomas and brainstem gliomas, new approaches to therapy have not yet resulted in improved outcomes. However, even for these tumors, advances in neuroimaging and new neurobiologic approaches hold substantial promise.