2006 Volume 15 Issue 1 Pages 25-30
Brain tumors amount to less than 2% of all malignant neoplasms; however, they are the most common solid tumors in children, causing nearly one quarter of all childhood cancer death, and the incidence of pediatric brain tumors seems to increase more rapidly than any other tumor type. The majority of adult glioblastomas (WHO grade IV) occur in older patients after a short clinical history without clinical or histopathological evidence of a less malignant precursor lesion (primary or de novo glioblastoma). Another type of glioblastoma, so-called secondary glioblastoma, progressively develops in younger patients more slowly from low-grade diffuse (WHO grade II) or anaplastic astrocytoma (WHO grade III). Distinct genetic pathways have been reported, related to tumor progression in adult astrocytic tumors. Pediatric glioblastomas resemble secondary glioblastomas in that the patients are young, but the tumors are mostly primary. Compared with the extensive efforts that has been directed at characterizing the molecular features of adult astrocytoma progression, relatively little data have been reported on pediatric tumors, in part reflecting the fact that these lesions are less common. It has also remained uncertain whether tumor classification into genetic subtypes as defined for adult astrocytomas could be defined for childhood astrocytomas. We reviewed whether the genetic alterations documented for adult astrocytomas are also operative in younger tumors.
