Telomerase reverse transcriptase promoter mutation– and O6-methylguanine DNA methyltransferase promoter methylation–mediated sensitivity to temozolomide in isocitrate dehydrogenase–wild-type glioblastoma: is there a link?
Dorothee Gramatzki, Jörg Felsberg, Bettina Hentschel, Marietta Wolter, Gabriele Schackert, Manfred Westphal, Luca Regli, Niklas Thon, Marcos Tatagiba, Wolfgang Wick, Uwe Schlegel, Dietmar Krex, Jakob Matschke, Patrick Roth, Marian Preetham Suresh, Marcel A. Kamp, Elisabeth J. Rushing, Torsten Pietsch, Andreas von Deimling, Michael Sabel, Markus Loeffler, Michael Weller, Guido Reifenberger
Abstract
AIM OF THE STUDY: -methylguanine DNA methyltransferase (MGMT) promoter-methylated tumours. Recent studies suggested that telomerase reverse transcriptase (TERT) promoter hotspot mutations may have an impact on the prognostic role of the MGMT status in patients with glioblastoma. METHODS: MGMT promoter methylation and TERT promoter mutation status were retrospectively assessed in a prospective cohort of patients with IDH-wild-type glioblastoma of the German Glioma Network (GGN) (n = 298) and an independent retrospective cohort from Düsseldorf, Germany, and Zurich, Switzerland (n = 302). RESULTS: In the GGN cohort, but not in the Düsseldorf/Zurich cohort, TERT promoter mutation was moderately associated with inferior outcomes in patients with MGMT promoter-unmethylated tumours (hazard ratio 1.74; 95% confidence interval: 1.07-2.82; p = 0.026). TERT promoter mutations were not associated with better outcomes in patients with MGMT promoter-methylated tumours in either cohort. The two different TERT promoter hotspot mutations (C228T and C250T) were not linked to distinct outcomes. CONCLUSIONS: Analysis of two independent cohorts of patients with glioblastoma did not confirm previous data, suggesting that TERT promoter mutations confer an enhanced benefit from TMZ in patients with MGMT promoter-methylated glioblastoma. Thus, diagnostic testing for TERT promoter mutations may not be required for prediction of TMZ sensitivity in patients with IDH-wild-type glioblastoma.