Childhood brain tumors.

Primary malignant tumors of the central nervous system (CNS) account for about 16% of all childhood malignancies. These tumors are the second most common type of childhood cancer and the most frequent of the solid tumors. The small increase in incidence noted over the past two decades most likely represents advancements in diagnostic technologies rather than true changes in disease frequency, though this is controversial. CNS tumors are diverse, representing many histological types and arising in a variety of anatomic sites. The most common malignant tumors include astrocytomas (52%), medulloblastomas/primitive neuroectodermal tumors (PNETs) (21%), gliomas (19%), and ependymomas (9%). The current 5-year survival rate for all pediatric CNS tumors is 67%, but rates differ considerably among tumor types. Treatment modalities also differ according to histological type. Currently, about 25% of patients are treated with surgery alone, 40% undergo surgery plus radiation, and 30% are treated with surgery, radiation, and chemotherapy. Survivors of childhood brain tumors are at substantial risk for increased morbidity and late mortality. Five-year survivors of brain tumors are 13 times more likely to die than healthy age- and sex-matched peers. Disease recurrence remains the single most common cause of late deaths (70%). Neurological, neurocognitive, and endocrine disturbances are the most prevalent disabilities observed among long-term survivors of pediatric brain tumors.