TY - JOUR AU - Stichel, Damian AU - Ebrahimi, Azadeh AU - Reuss, David AU - Schrimpf, Daniel AU - Ono, Takahiro AU - Shirahata, Mitsuaki AU - Reifenberger, Guido AU - Weller, Michael AU - Hänggi, Daniel AU - Wick, Wolfgang AU - Herold-Mende, Christel AU - Westphal, Manfred AU - Brandner, Sebastian AU - Pfister, Stefan AU - Capper, David AU - Sahm, Felix AU - von Deimling, Andreas TI - Distribution of EGFR amplification, combined chromosome 7 gain and chromosome 10 loss, and TERT promoter mutation in brain tumors and their potential for the reclassification of IDHwt astrocytoma to glioblastoma. JO - Acta neuropathologica VL - 136 IS - 5 SN - 1432-0533 CY - Berlin PB - Springer M1 - DKFZ-2018-01456 SP - 793-803 PY - 2018 AB - EGFR amplification (EGFRamp), the combination of gain of chromosome 7 and loss of chromosome 10 (7+/10-), and TERT promoter mutation (pTERTmut) are alterations frequently observed in adult IDH-wild-type (IDHwt) glioblastoma (GBM). In the absence of endothelial proliferation and/or necrosis, these alterations currently are considered to serve as a surrogate for upgrading IDHwt diffuse or anaplastic astrocytoma to GBM. Here, we set out to determine the distribution of EGFRamp, 7+/10-, and pTERTmut by analyzing high-resolution copy-number profiles and next-generation sequencing data of primary brain tumors. In addition, we addressed the question whether combinations of partial gains on chromosome 7 and partial losses on chromosome 10 exhibited a diagnostic and prognostic value similar to that of complete 7+/10-. Several such combinations proved relevant and were combined as the 7/10 signature. Our results demonstrate that EGFRamp and the 7/10 signature are closely associated with IDHwt GBM. In contrast, pTERTmut is less specific for IDHwt GBM. We conclude that, in the absence of endothelial proliferation and/or necrosis, the detection of EGFRamp is a very strong surrogate marker for the diagnosis of GBM in IDHwt diffuse astrocytic tumors. The 7/10 signature is also a strong surrogate marker. However, care should be taken to exclude pleomorphic xanthoastrocytoma. pTERTmut is less restricted to this entity and needs companion analysis by other molecular markers to serve as a surrogate for diagnosing IDHwt GBM. A combination of any two of EGFRamp, the 7/10 signature and pTERTmut, is highly specific for IDHwt GBM and the combination of all three alterations is frequent and exclusively seen in IDHwt GBM. LB - PUB:(DE-HGF)16 C6 - pmid:30187121 DO - DOI:10.1007/s00401-018-1905-0 UR - https://inrepo02.dkfz.de/record/137576 ER -