TCG2, TCG3 and TCG4 tumor characterization for oncogenic alterations commonly found in high-grade gliomas.

1Primary diagnoses (determined in 2001 by a first pathologist according to the WHO classification 2000) were compared to a second opinion (given by an independent pathologist in 2013 according to the WHO classification 2007). AO  =  anaplastic oligodendroglioma.
2EGFR amplification was assessed using CGH array and FISH, leading to consistent results.
3The expression of the EGFR variant III was determined by western-blotting.
4EGFR protein overexpression was assesed by immunohistochemical detection and compared to non tumor tissue.
5Phospho-EGFR expression level was determined using the Bio-plex phosphotrein arrays.
6PTEN status was investigated using three techniques: CGH array, qRT-PCR and protein expression analysis by western-blotting, leading to consistent results. (-)  =  PTEN loss.
7PIK3CA mutation analysis (exons 9 & 20) was performed using direct sequencing.
8IDH1 mutation was assessed by immunohistochemistry;
91p/19q Codeletion was determined using microsatellite analysis for loss of heterozygosity on chromosome 1 and 19q, as previously described. In parallel, IHC studies showed no expression of alpha-internexin.
10p53 status was determined by FASAY and confirmed by IHC: WT  =  wild type or MUT  =  Mutated.
11MGMT promotor methylation status was evaluated with the methylation specific polymerase chain reaction after DNA modification by sodium bisulfite: M  =  mutated or U  =  unmethylated.