Glioblastomas: correlation between oligodendroglial components, genetic abnormalities, and prognosis.

It has been demonstrated that a small percentage (approximately 15%) of glioblastomas (GBM) presents an oligodendroglial component with a variable frequency of chromosome 1p and 19q deletions, the genetic alteration related to chemotherapy response and longer survival in oligodendrogliomas. There is a growing interest in investigating 1p and 19q losses in hybrid gliomas and their impact on prognosis. A series of 88 GBMs was investigated regarding 1p and/or 19q losses, 24 with oligodendroglioma-like areas, using quantitative microsatellite analysis and/or fluorescent in situ hybridization.