We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer.

Glioblastoma (GBM) constitutes the most common and aggressive primary brain tumor. To better understand how GBM evolves we analyzed longitudinal genomic and transcriptomic data of 114 patients. The analysis reveals a highly branched evolutionary pattern in which 63% of patients experience expression-based subtype changes. The branching pattern together with estimates of evolutionary rates suggest that the relapse associated clone typically preexisted years before diagnosis. 15% of tumors present hypermutations at relapse in highly expressed genes with a clear mutational signature. We find that 11% of recurrent tumors harbor mutations in LTBP4, a protein binding to TGF-β. Silencing LTBP4 in GBM cells leads to TGF-β activity suppression and decreased proliferation. In IDH1-wild-type recurrent GBM, high LTBP4 expression is associated with worse prognosis, highlighting the TGF-β pathway as a potential therapeutic target in GBM.

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Purpose Oncogenic fusions consisting of FGFR and TACC are present in a subgroup of glioblastoma (GBM) and other human cancers and have been proposed as new therapeutic targets. We analyzed frequency, molecular features of FGFR-TACC fusions, and explored the therapeutic efficacy of inhibiting FGFR kinase in GBM and grade-II–III glioma. Experimental Design Overall, 795 gliomas (584 GBM, 85 grade-II–III with wild-type and 126 with IDH1/2 mutation) were screened for FGFR-TACC breakpoints and associated molecular profile. We also analyzed expression of the FGFR3 and TACC3 components of the fusions. The effects of the specific FGFR inhibitor JNJ-42756493 for FGFR3-TACC3-positive glioma were determined in preclinical experiments. Two patients with advanced FGFR3-TACC3-positive GBM received JNJ-42756493 and were assessed for therapeutic response. Results Three of 85 IDH1/2 wild type (3.5%) but none of 126 IDH1/2 mutant grade-II–III glioma harbored FGFR3-TACC3 fusions. FGFR-TACC rearrangements were present in 17 of 584 GBM (2.9%). FGFR3-TACC3 fusions were associated with strong and homogeneous FGFR3 immunostaining. They are mutually exclusive with IDH1/2 mutations and EGFR amplification whereas co-occur with CDK4 amplification. JNJ-42756493 inhibited growth of glioma cells harboring FGFR3-TACC3 in vitro and in vivo. The two patients with FGFR3-TACC3 rearrangements who received JNJ-42756493 manifested clinical improvement with stable disease and minor response, respectively. Conclusions RT-PCR-sequencing is a sensitive and specific method to identify FGFR-TACC-positive patients. FGFR3-TACC3 fusions are associated with uniform intra-tumor expression of the fusion protein. The clinical response observed in the FGFR3-TACC3-positive patients treated with a FGFR inhibitor supports clinical studies of FGFR inhibition in FGFR-TACC-positive patients.

Purpose: Sodium fluorescein is a dye that, intravenously injected, selectively accumulates in high-grade glioma (HGG) tissue through a damaged blood-brain barrier. In this article, the final results of a multicentric prospective phase II trial (FLUO-GLIO) on fluorescein-guided HGG resection through a dedicated filter on the surgical microscope were reported.Methods: Patients with suspected HGGs considered suitable for removal were eligible to participate in this trial. Fluorescein was intravenously injected at a dose of 5 to 10 mg/kg. The primary endpoint was the percentage of patients with histologically confirmed HGGs, without contrast-enhancing tumor at the immediate postoperative MRI. Secondary endpoints were PFS, residual tumor on postoperative MRI, overall survival, neurologic deficits, and fluorescein-related toxicity. The sensitivity and specificity of fluorescein in identifying tumor tissue were estimated by fluorescent and nonfluorescent biopsies at the tumor margin. The study was registered on the European Regulatory Authorities website (EudraCT 2011-002527-18).Results: Fifty-seven patients aged 45 to 75 years were screened for participation, and 46 were considered for primary and secondary endpoints. Mean preoperative tumor volume was 28.75 cm 3 (range, 1.3-87.8 cm 3 ). Thirty-eight patients (82.6%) underwent a complete tumor removal. Median follow-up was 11 months. PFS-6 and PFS-12 were 56.6% and 15.2%. Median survival was 12 months. No adverse reaction related to SF administration was recorded. The sensitivity and specificity of fluorescein in identifying tumor tissue were respectively 80.8% and 79.1%.Conclusions: Fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and enables a high percentage of contrast-enhancing tumor in patients with HGGs.