Open Access

Gunther Nussbaumer, Martin Benesch, Yura Grabovska, Alan Mackay, David Castel, Jacques Grill, Marta M. Alonso, Manila Antonelli, Simon Bailey, Joshua N. Baugh, Veronica Biassoni, Mirjam Blattner-Johnson, Alberto Broniscer, Andrea Carai, Giovanna Stefania Colafati, Niclas Colditz, Selim Corbacioglu, Shauna Crampsie, Natacha Entz-Werle, Matthias Eyrich, Lea L. Friker, Michael C. Frühwald, Maria Luisa Garrè, Nicolas U. Gerber, Felice Giangaspero, Maria J. Gil-da-Costa, Norbert Graf, Darren Hargrave, Peter Hauser, Ulrich Herrlinger, Marion Hoffmann, Esther Hulleman, Elisa Izquierdo, Sandra Jacobs, Michael Karremann, Antonis Kattamis, Rejin Kebudi, Rolf-Dieter Kortmann, Robert Kwiecien, Maura Massimino, Angela Mastronuzzi, Evelina Miele, Giovanni Morana, Claudia M. Noack, Virve Pentikainen, Thomas Perwein, Stefan M. Pfister, Torsten Pietsch, Kleoniki Roka, Sabrina Rossi, Stefan Rutkowski, Elisabetta Schiavello, Clemens Seidel, Jaroslav Štěrba, Dominik Sturm, David Sumerauer, Anna Tacke, Sara Temelso, Chiara Valentini, Dannis van Vuurden, Pascale Varlet, Sophie E. M. Veldhuijzen van Zanten, Maria Vinci, André O. von Bueren, Monika Warmuth-Metz, Pieter Wesseling, Maria Wiese, Johannes E. A. Wolff, Josef Zamecnik, Andrés Morales La Madrid, Brigitte Bison, Gerrit H. Gielen, David T. W. Jones, Chris Jones, Christof M. Kramm

• Background The term gliomatosis cerebri (GC), a radiology-defined highly infiltrating diffuse glioma, has been abandoned since molecular GC-associated features could not be established. Methods We conducted a multinational retrospective study of 104 children and adolescents with GC providing comprehensive clinical and (epi-)genetic characterization. Results Median overall survival (OS) was 15.5 months (interquartile range, 10.9–27.7) with a 2-year survival rate of 28%. Histopathological grading correlated significantly with median OS: CNS WHO grade II: 47.8 months (25.2–55.7); grade III: 15.9 months (11.4–26.3); grade IV: 10.4 months (8.8–14.4). By DNA methylation profiling (n = 49), most tumors were classified as pediatric-type diffuse high-grade glioma (pedHGG), H3-/IDH-wild-type (n = 31/49, 63.3%) with enriched subclasses pedHGG_RTK2 (n = 19), pedHGG_A/B (n = 6), and pedHGG_MYCN (n = 5), but only one pedHGG_RTK1 case. Within the pedHGG, H3-/IDH-wild-type subgroup,Background The term gliomatosis cerebri (GC), a radiology-defined highly infiltrating diffuse glioma, has been abandoned since molecular GC-associated features could not be established. Methods We conducted a multinational retrospective study of 104 children and adolescents with GC providing comprehensive clinical and (epi-)genetic characterization. Results Median overall survival (OS) was 15.5 months (interquartile range, 10.9–27.7) with a 2-year survival rate of 28%. Histopathological grading correlated significantly with median OS: CNS WHO grade II: 47.8 months (25.2–55.7); grade III: 15.9 months (11.4–26.3); grade IV: 10.4 months (8.8–14.4). By DNA methylation profiling (n = 49), most tumors were classified as pediatric-type diffuse high-grade glioma (pedHGG), H3-/IDH-wild-type (n = 31/49, 63.3%) with enriched subclasses pedHGG_RTK2 (n = 19), pedHGG_A/B (n = 6), and pedHGG_MYCN (n = 5), but only one pedHGG_RTK1 case. Within the pedHGG, H3-/IDH-wild-type subgroup, recurrent alterations in EGFR (n = 10) and BCOR (n = 9) were identified. Additionally, we observed structural aberrations in chromosome 6 in 16/49 tumors (32.7%) across tumor types. In the pedHGG, H3-/IDH-wild-type subgroup TP53 alterations had a significant negative effect on OS. Conclusions Contrary to previous studies, our representative pediatric GC study provides evidence that GC has a strong predilection to arise on the background of specific molecular features (especially pedHGG_RTK2, pedHGG_A/B, EGFR and BCOR mutations, chromosome 6 rearrangements).…