[Glioblastoma: clinical, radiological and biological prognostic factors]

The main prognostic factors of glioblastomas (GBM) are age, neurological and cognitive status, frontal tumor location, extent of surgical resection, adjuvant therapies received, presence of IDH1 mutations, and MGMT expression. Other molecular prognostic factors have been proposed, such as mutations of TP53 and PTEN, amplification of EGFR, and deletion of 10q, but their prognostic values remain controversial. MGMT promotor gene methylation is correlated with higher chemosensitivity and consequently is a good prognostic factor only in patients treated with chemotherapy. In the future, the gene expression profile will probably be a stronger prognostic factor than histological grade, but the most relevant gene clusters, whose expression may be correlated with survival, remain to be identified. Long survivors are characterized by younger age, better neurological status, and a more aggressive therapeutic strategy. In daily clinical practice, recursive partitioning analysis (RPA) classifications can estimate the median survival of a given patient according to several basic factors. RPA class is also important so as to adapt individual therapeutic strategies, considering that the benefit of adjuvant treatments tends to decrease in the highest RPA class patients.