Published in:
01-12-2017 | Diagnostic Neuroradiology
New prognostic factor telomerase reverse transcriptase promotor mutation presents without MR imaging biomarkers in primary glioblastoma
Authors:
Tunc F. Ersoy, Vera C. Keil, Dariusch R. Hadizadeh, Gerrit H. Gielen, Rolf Fimmers, Andreas Waha, Barbara Heidenreich, Rajiv Kumar, Hans H. Schild, Matthias Simon
Published in:
Neuroradiology
|
Issue 12/2017
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Abstract
Purpose
Magnetic resonance (MR) imaging biomarkers can assist in the non-invasive assessment of the genetic status in glioblastomas (GBMs). Telomerase reverse transcriptase (TERT) promoter mutations are associated with a negative prognosis. This study was performed to identify MR imaging biomarkers to forecast the TERT mutation status.
Methods
Pre-operative MRIs of 64/67 genetically confirmed primary GBM patients (51/67
TERT-mutated with rs2853669 polymorphism) were analyzed according to Visually AcceSAble Rembrandt Images (VASARI) (
https://wiki.cancerimagingarchive.net/display/Public/VASARI+Research+Project) imaging criteria by three radiological raters.
TERT mutation and O
6-methylguanine-DNA methyltransferase (
MGMT) hypermethylation data were obtained through direct and pyrosequencing as described in a previous study. Clinical data were derived from a prospectively maintained electronic database. Associations of potential imaging biomarkers and genetic status were assessed by Fisher and Mann-Whitney
U tests and stepwise linear regression.
Results
No imaging biomarkers could be identified to predict TERT mutational status (alone or in conjunction with TERT promoter polymorphism rs2853669 AA-allele). TERT promoter mutations were more common in patients with tumor-associated seizures as first symptom (26/30 vs. 25/37, p = 0.07); these showed significantly smaller tumors [13.1 (9.0–19.0) vs. 24.0 (16.6–37.5) all cm3; p = 0.007] and prolonged median overall survival [17.0 (11.5–28.0) vs. 9.0 (4.0–12.0) all months; p = 0.02]. TERT-mutated GBMs were underrepresented in the extended angularis region (p = 0.03), whereas MGMT-methylated GBMs were overrepresented in the corpus callosum (p = 0.03) and underrepresented temporomesially (p = 0.01).
Conclusion
Imaging biomarkers for prediction of TERT mutation status remain weak and cannot be derived from the VASARI protocol. Tumor-associated seizures are less common in TERT mutated glioblastomas.