[Genetic factors in the pathogenesis of brain tumors].

The biological properties of tumor cells are determined by, mostly acquired, alterations of proliferation-relevant genes that can provide valuable diagnostic and prognostic parameters. Meningiomas and gliomas are among the genetically best characterized solid tumors. Here, specific patterns of primary and secondary genetic aberrations have been identified and shown to be correlated with clinical parameters such as recurrency of meningiomas or malignant progression of astrocytomas. Focal progression leading to intratumoral heterogeneity, which is most strikingly seen in gliomas, results from complex mechanisms of mutation and selection of tumor cells that are also iatrogenically influenced through radiotherapy and chemotherapy.