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Background Incidence and characteristics of pseudoprogression in isocitrate dehydrogenase-mutant high-grade gliomas (IDHmt HGG) remain to be specifically described. Methods We analyzed pseudoprogression characteristics and explored the possibility of pseudoprogression misdiagnosis in IDHmt HGG patients, treated with radiotherapy (RT) (with or without chemotherapy [CT]), included in the French POLA network. Pseudoprogression was analyzed in patients with MRI available for review (reference cohort, n = 200). Pseudoprogression misdiagnosis was estimated in this cohort and in an independent cohort (control cohort, n = 543) based on progression-free survival before and after first progression. Results In the reference cohort, 38 patients (19%) presented a pseudoprogression after a median time of 10.5 months after RT. Pseudoprogression characteristics were similar across IDHmt HGG subtypes. In most patients, it consisted of the appearance of one or several infracentimetric, asymptomatic, contrast-enhanced lesions occurring within 2 years after RT. The only factor associated with pseudoprogression occurrence was adjuvant PCV CT. Among patients considered as having a first true progression, 7 out of 41 (17%) in the reference cohort and 35 out of 203 (17%) in the control cohort were retrospectively suspected to have a misdiagnosed pseudoprogression. Patients with a misdiagnosed pseudoprogression were characterized by a time to event and an outcome similar to that of patients with a pseudoprogression but presented with larger and more symptomatic lesions. Conclusion In patients with an IDHmt HGG, pseudoprogression occurs later than in IDH-wildtype glioblastomas and seems not only frequent but also frequently misdiagnosed. Within the first 2 years after RT, the possibility of a pseudoprogression should be carefully considered.

International audience; Background: Describe the characteristics, patterns of care, and predictive geriatric factors of elderly patients with IDHm high-grade glioma (HGG) included in the French POLA network. Material and Methods: The characteristics of elderly (≥70 years) patients IDHm HGG were compared to those of younger patients IDHm HGG (

ObjectiveTo assess whether RAF and MEK inhibitors (RAFi/MEKi) can provide long-term clinical benefit in adult patients with BRAF V600–mutant glial and glioneuronal tumors (GGNTs), we analyzed tumor response and long-term outcome in a retrospective cohort.MethodsWe performed a retrospective search in the institutional databases of 6 neuro-oncology departments for adult patients with recurrent or disseminated BRAF V600–mutant GGNTs treated with RAFi/MEKi.ResultsTwenty-eight adults with recurrent or disseminated BRAF V600–mutant gangliogliomas (n = 9), pleomorphic xanthoastrocytomas (n = 9), and diffuse gliomas (n = 10) were included in the study. At the time that treatment with RAFi/MEKi was started, all tumors displayed radiologic features of high-grade neoplasms. Thirteen patients received RAFi as single agents (vemurafenib [n = 11], dabrafenib [n = 2]), and 15 received combinations of RAFi/MEKi (vemurafenib + cobimetinib [n = 5], dabrafenib + trametinib [n = 10]). Eleven patients achieved a partial or complete response (11 of 28, 39%), with a median reduction of −78% in their tumor burden. Responders experienced a median increase of 10 points in their Karnofsky Performance Status (KPS) score and a median progression-free survival of 18 months, which was longer than achieved with first-line treatment (i.e., 7 months, p = 0.047). Responders had better KPS score (p = 0.018) and tended to be younger (p = 0.061) and to be treated earlier (p = 0.099) compared to nonresponders. Five patients were rechallenged with RAFi/MEKi at progression, with novel tumor responses in 2. On univariate and multivariate analyses, response to RAFi/MEKi was an independent predictor of overall survival.ConclusionsOur study highlights the long-term clinical benefits of RAFi/MEKi in adult patients with BRAF V600–mutant GGNTs and encourages rechallenge in responders.Classification of EvidenceThis study provides Class III evidence that, for adult patients with BRAF V600-mutant GGNT, RAFi/MEKi can reduce tumor burden and provide clinical benefit.

Mucosae-associated lymphoid tissue (MALT) lymphomas are a rare and poorly understood form of primary central nervous system lymphoma (PCNSL). The aim of this study was to better describe these tumors, their management and their long-term prognosis.Patients with primary CNS MALT lymphoma (PCNSML) were retrospectively selected from the database on PCNSL of the Pitié-Salpêtrière Hospital.Of 662 PCNSL, 11 (1.7%) PCNSML (9 females and 2 males, median age: 56 years) were selected. The median time from first symptoms to diagnosis was 13 months. Location was dural in 8 cases and parenchymal in 3 cases. The disease was multifocal/diffuse in 7 cases. In first line, all patients received chemotherapy (high-dose methotrexate (HD-MTX) based chemotherapy (n = 4) and non-HD-MTX-based chemotherapy (n = 7)), preceded by surgery in 4 cases. None received radiotherapy. According to the IPCG (International PCNSL Collaborative Group) criteria, the overall response rate was 7/11 (64%). At latest news, 5 patients had persistent contrast enhancement, stable with no treatment since a median of 57 months, raising the question of complete response despite persisting contrast enhancement. No patient developed neurotoxicity except for one patient who subsequently received radiotherapy. The median follow-up was 109 months. The median progression-free survival was 78.0 months and the 10-year overall survival rate was 90%.This is the largest series demonstrating that chemotherapy is an efficient treatment in PCNSML, with an excellent long-term outcome and the absence of neurotoxicity, and calling into question the relevance of the IPCG criteria for the evaluation of response.

Background In glioma, TERT promoter mutation and loss of ATRX (ATRX loss) are associated with reactivation of telomerase or alternative lengthening of telomeres (ALT), respectively, i.e. the two telomere maintenance mechanisms (TMM). Strangely, 25% of gliomas have been reported to display neither or both of these alterations. Materials and methods The C-circle (CC) assay was adapted to tumor (formalin-fixed paraffin-embedded and frozen) and blood samples to investigate the TMM. Results We constructed a CC-based algorithm able to identify the TMM and reported a sensitivity of 100% and a specificity of 97.3% (n = 284 gliomas). By combining the TMM, the mutational status of the isocitrate dehydrogenase 1/2 (IDH) gene (IDHmt), and the histological grading, we propose a new classification tool: TeloDIAG. This classification defined five subtypes: tOD, tLGA, tGBM_IDHmt, tGBM, and tAIV, corresponding to oligodendroglioma, IDHmt low-grade astrocytoma, IDHmt glioblastoma, and IDHwt glioblastoma (GBM), respectively; the last class gathers ALT+ IDHwt gliomas that tend to be related to longer survival (21.2 months) than tGBM (16.5 months). The TeloDIAG was 99% concordant with the World Health Organization classification (n = 312), and further modified the classification of 55 of 144 (38%) gliomas with atypical molecular characteristics. As an example, 14 of 69 (20%) of TERTwt, ATRXwt, and IDHwt GBM were actually tAIV. Outstandingly, CC in blood sampled from IDHmt astrocytoma patients was detected with a sensitivity of 56% and a specificity of 97% (n = 206 gliomas and 30 healthy donors). Conclusion The TeloDIAG is a new, simple, and effective tool helping in glioma diagnosis and a promising option for liquid biopsy.

BACKGROUND The distinction between grade 2 and 3 is instrumental to choose between observational follow-up and adjuvant treatment in resected astrocytoma IDH-mutant. However, criteria for discriminating grade 2 and 3 tumors have not been updated since the WHO 2007 classification. There is no consensus on the method of evaluation of the mitotic activity or a mitosis cut-off for grading. The objectives were to evaluate the maximal mitotic activity on a series of resected astrocytoma IDH-mutant and assess its prognostic impact on survival. METHODS Maximal mitotic activity on consecutive high-power fields corresponding to 3 mm2 was examined in 118 lower-grade astrocytomas IDH-mutant. The prognostic value for time-to-treatment (TTT) and overall survival (OS) of mitotic activity as well as other prognostic factors (including age, performance status, presurgical tumor volume, plurilobar involvement, postsurgical residual tumor volume, midline involvement) was assessed in tumors with (i) ATRX loss, and (ii) without CDKN2A homozygous deletion, lesional enhancement, histological necrosis nor microvascular proliferation. RESULTS Among the 75 (64%) tumors which had gone through observational follow-up after resection, maximal mitotic activity, post-surgical residual volume and plurilobar involvement were independent prognostic factors of TTT (p < 0.0001). A threshold of mitotic activity for grade 2 was fitted using TTT and OS parameters. Using this threshold, patients with “grade 2 tumors” had a median TTT of 55 months versus 19 months for “grade 3” (p= 0.0057) and a median OS of 102 months versus 73 months respectively (p= 0.001). Residual volume < 1 cm3 was associated with longer OS (113 months versus 88 months, p= 0.0021). CONCLUSIONS The combination of mitotic activity and postsurgical residual volume improves prognostication in resected astrocytoma IDH-mutant. This novel risk assessment method could identify the best candidates for observational follow-up.

International audience

BackgroundAstroblastoma (ABM) is a rare glial brain tumor. Recurrent meningioma 1 (MN1) alterations have been recently identified in most pediatric cases. Adolescent and adult cases, however, remain molecularly poorly defined.Materials and MethodsWe performed clinical and molecular characterization of a retrospective cohort of 14 adult and 1 adolescent ABM.ResultsStrikingly, we found that MN1 fusions are a rare event in this age group (1/15). Using methylation profiling and targeted sequencing, most cases were reclassified as either pleomorphic xanthoastrocytomas (PXA)-like or high-grade glioma (HGG)-like. PXA-like ABM show BRAF mutation (6/7 with V600E mutation and 1/7 with G466E mutation) and CD34 expression. Conversely, HGG-like ABM harbored specific alterations of diffuse midline glioma (2/5) or glioblastoma (GBM; 3/5). These latter patients showed an unfavorable clinical course with significantly shorter overall survival (p = .021). Mitogen-activated protein kinase pathway alterations (including FGFR fusion, BRAF and NF1 mutations) were present in 10 of 15 patients and overrepresented in the HGG-like group (3/5) compared with previously reported prevalence of these alterations in GBM and diffuse midline glioma.ConclusionWe suggest that gliomas with astroblastic features include a variety of molecularly sharply defined entities. Adult ABM harboring molecular features of PXA and HGG should be reclassified. Central nervous system high-grade neuroepithelial tumors with MN1 alterations and histology of ABM appear to be uncommon in adults. Astroblastic morphology in adults should thus prompt thorough molecular investigation aiming at a clear histomolecular diagnosis and identifying actionable drug targets, especially in the mitogen-activated protein kinase pathway.Implications for PracticeAstroblastoma (ABM) remains a poorly defined and controversial entity. Although meningioma 1 alterations seem to define a large subset of pediatric cases, adult cases remain molecularly poorly defined. This comprehensive molecular characterization of 1 adolescent and 14 adult ABM revealed that adult ABM histology comprises several molecularly defined entities, which explains clinical diversity and identifies actionable targets. Namely, pleomorphic xanthoastrocytoma-like ABM cases show a favorable prognosis whereas high-grade glioma (glioblastoma and diffuse midline gliome)-like ABM show significantly worse clinical courses. These results call for in-depth molecular analysis of adult gliomas with astroblastic features for diagnostic and therapeutic purposes.

2007 Background: There is a need to develop new treatments in IDH-mutant high-grade gliomas recurring after radiotherapy and chemotherapy. Based on preclinical studies showing that IDH-mutant tumors could be vulnerable to PARP inhibition we launched a phase II study to test the efficacy of olaparib (Lynparza) monotherapy in this population. Methods: Adults with recurrent high-grade IDH-mutant gliomas after radiotherapy and at least one line of alkylating chemotherapy (PCV or TMZ), KPS > 60, normal organ function were enrolled. The primary endpoint was 6 months PFS according to RANO criteria. Patients were treated with olaparib 300 mg twice daily. We used a single-stage Fleming design with p0 = 30%, p1 = 50%, a type I unilateral error rate of 5% and a power of 80%. Results: 35 patients with recurrent IDH-mutant gliomas (IDH1R132H-mutant n = 32, other IDH mutation n = 3, 1p/19 codeleted n = 16, 1p/19q non-codeleted n = 14) were enrolled (malignantly transformed low-grade gliomas n = 21, anaplastic gliomas n = 8, glioblastomas n = 6). Median time since diagnosis was 7.4 years (1-22 years), median time since radiotherapy was 2.8 years (0.6-18 years), median number of previous chemotherapy lines was 2 (1-5). With a median follow-up of 11 months, 30 patients had stopped treatment due to tumor progression and 2 patients were still on treatment 16 to 18 months after treatment start. At 6 months, 11/35 patients were progression-free (31 %). According to RANO criteria, based on local investigator analysis, 2 patients (5%) had a partial response and 14 patients a stable disease (37%) with a median duration of response of 9 months (4-18 months+). Median PFS and OS were 2.3 and 15.9 months and were similar in 1p/19q codeleted and non-codeleted patients. A grade 3 olaparib-related adverse event was observed in 5 patients (14%, lymphopenia n = 3, fatigue n = 2, diarrhea n = 1) and a grade 2 in 15 patients (43%), most frequently consisting in fatigue (23%), gastrointestinal disorders (20%) and lymphopenia (20%). No patient definitively stopped olaparib due to side effects. Conclusions: In this heavily pre-treated population of recurrent IDH-mutant gliomas, olaparib monotherapy was well tolerated and resulted in some activity supporting its evaluation in association with alkylating chemotherapy in recurrent IDH-mutant gliomas in future studies. Clinical trial information: NCT03561870.

The incidence and risk factors associated with radiation-induced leukoencephalopathy (RIL) in long-term survivors of high-grade glioma (HGG) are still poorly investigated. We performed a retrospective research in our institutional database for patients with supratentorial HGG treated with focal radiotherapy, having a progression-free overall survival > 30 months and available germline DNA. We reviewed MRI scans for signs of leukoencephalopathy on T2/FLAIR sequences, and medical records for information on cerebrovascular risk factors and neurological symptoms. We investigated a panel of candidate single nucleotide polymorphisms (SNPs) to assess genetic risk. Eighty-one HGG patients (18 grade IV and 63 grade III, 50M/31F) were included in the study. The median age at the time of radiotherapy was 48 years old (range 18–69). The median follow-up after the completion of radiotherapy was 79 months. A total of 44 patients (44/81, 54.3%) developed RIL during follow-up. Twenty-nine of the 44 patients developed consistent symptoms such as subcortical dementia (n = 28), gait disturbances (n = 12), and urinary incontinence (n = 9). The cumulative incidence of RIL was 21% at 12 months, 42% at 36 months, and 48% at 60 months. Age > 60 years, smoking, and the germline SNP rs2120825 (PPARg locus) were associated with an increased risk of RIL. Our study identified potential risk factors for the development of RIL (age, smoking, and the germline SNP rs2120825) and established the rationale for testing PPARg agonists in the prevention and management of late-delayed radiation-induced neurotoxicity.

BACKGROUND The integration of molecular markers into the WHO 2016 classification has clarified the complex diagnosis of gliomas. Among these biomarkers, the TERT promoter mutation and the loss of ATRX (ATRX loss) are mutually exclusive alterations associated with re-activation of telomerase or alternative lengthening of telomeres (ALT), respectively. Strangely, 25% of gliomas display neither or both these alterations, a situation referred to as abnormal telomere maintenance mechanism (aTMM). MATERIAL AND METHODS To investigate the TMM actually involved in gliomas, the C-circle (CC) assay was adapted to tumor (FFPE and frozen) samples. RESULTS We constructed a CC-based algorithm able to identify the TMM of 284 gliomas with either TERT or ATRX alteration, with a sensitivity of 100% and a specificity of 97.3%, and succeeded in deciphering the TMM involved in 122 aTMM gliomas. Additionally, the combination of the TMM, the mutational status of the Isocitrate dehydrogenase 1/2 (IDH) gene, and the histological grading was used as base for a new classification: TeloDIAG. Six subtypes are defined in this classification: tOD, tLGA, tGBM_IDHmt, tGBM, and tAIV, corresponding to oligodendroglioma, IDHmt low grade astrocytoma, IDHmt glioblastoma, and IDHwt glioblastoma, respectively, the last class gathers ALT+ IDHwt glioma. The TeloDIAG diagnosis is 99% concordant with the WHO classification for glioma displaying typical molecular characteristics (N=312). It modified the classification of 38% (N=156) discordant tumors, such as IDHwt Astrocytoma, aTMM tumors, or gliomas with unexpected TMM (e.g. TERTwt oligodendroglioma, ATRX loss GBM). Interestingly, 20% (N=69) of TERTwt, ATRXwt, or IDHwt GBM were actually tAIV, which is remarkable as tAIV-glioma patients’ survival tended to be longer (21.2 months) than tGBM patients’ survival (16.5 months). Importantly, CC in blood sampled from IDHmt astrocytoma patients was detected with a sensitivity of 56% and a specificity of 95% (N = 206). CONCLUSION In sum, the TeloDIAG is a new, simple, and efficient tool helping in glioma diagnosis and a promising option for liquid biopsy

Background IDH-mutant anaplastic astrocytomas (AAs) are chemosensitive tumors for which the best choice of adjuvant chemotherapy between procarbazine, lomustine, and vincristine (PCV) or temozolomide (TMZ) after radiotherapy (RT) remains unclear. Methods In a large cohort of patients with histologically proven 2016 World Health Organization classification AA with IDH1/2 mutations included in the French national POLA cohort (n = 355), the primary objective was to compare progression-free survival (PFS) between the two treatment regimens (n = 311). Secondary endpoints were overall survival (OS), progression type, pseudoprogression rate, and toxicity. Results The 4-year PFS in the RT + PCV arm was 70.8% versus 53.5% in the RT + TMZ arm, with a hazard ratio (HR) of 0.58 (95% confidence interval [CI], 0.38–0.87; p = .0074) in univariable analysis and 0.63 (95% CI, 0.41–0.97; p = .0348) in multivariable analysis. The 4-year OS in the RT + PCV arm was 84.3% versus 76.6% in the RT + TMZ arm, with an HR of 0.57 (95% CI, 0.30–1.05; p = .0675) in univariable analysis. Toxicity was significantly higher in the RT + PCV arm with more grade ≥3 toxicity (46.7% vs. 8.6%, p < .0001). Conclusion RT + PCV significantly improved PFS compared with RT + TMZ for IDH-mutant AA. However, RT + TMZ was better tolerated. Implications for Practice In the absence of fully conducted randomized trials comparing procarbazine, lomustine, and vincristine (PCV) with temozolomide (TMZ) in adjuvant treatment after radiotherapy (RT) for the management of IDH-mutant anaplastic astrocytoma (AA) and a similar level of evidence, these two chemotherapies are both equally recommended in international guidelines. This study in a national cohort of IDH-mutant AA defined according the 2016 World Health Organization (WHO) classification shows for the first time that the RT + PCV regimen significantly improves progression-free survival in comparison with the RT + TMZ regimen. Even if at the time of analysis the difference in overall survival was not significant, this result provides new evidence for the debate about the chemotherapy regimen to prescribe in adjuvant treatment to RT for WHO 2016 IDH-mutant AA.

International audience; Overall, tumors of primary central nervous system (CNS) are quite common in adults with an incidence rate close to 30 new cases/100,000 inhabitants per year. Significant clinical and biological advances have been accomplished in the most common adult primary CNS tumors (i.e., diffuse gliomas). However, most CNS tumor subtypes are rare with an incidence rate below the threshold defining rare disease of 6.0 new cases/100,000 inhabitants per year. Close to 150 entities of primary CNS tumors have now been identified by the novel integrated histomolecular classification published by the World Health Organization (WHO) and its updates by the c-IMPACT NOW consortium (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy). While these entities can be better classified into smaller groups either by their histomolecular features and/or by their location, assessing their treatment by clinical trials and improving the survival of patients remain challenging. Despite these tumors are rare, research, and advances remain slower compared to diffuse gliomas for instance. In some cases (i.e., ependymoma, medulloblastoma) the understanding is high because single or few driver mutations have been defined. The European Union has launched European Reference Networks (ERNs) dedicated to support advances on the clinical side of rare diseases including rare cancers. The ERN for rare solid adult tumors is termed EURACAN. Within EURACAN, Domain 10 brings together the European patient advocacy groups (ePAGs) and physicians dedicated to improving outcomes in rare primary CNS tumors and also aims at supporting research, care and teaching in the field. In this review, we discuss the relevant biological and clinical characteristics, clinical management of patients, and research directions for the following types of rare primary CNS tumors: medulloblastoma, pineal region tumors, glioneuronal and rare glial tumors, ependymal tumors, grade III meningioma and mesenchymal tumors, primary central nervous system lymphoma, germ cell tumors, spinal cord tumors and rare pituitary tumors.

BackgroundsThe incidence of germline mutations in the newly discovered cryptic exon (E1’) of VHL gene in patients with von Hippel-Lindau (VHL) disease and in patients with paraganglioma or pheochromocytoma (PPGL) is not currently known.MethodsWe studied a large international multicentre cohort of 1167 patients with a previous negative genetic testing. Germline DNA from 75 patients with a single tumour of the VHL spectrum (‘Single VHL tumour’ cohort), 70 patients with multiple tumours of the VHL spectrum (‘Multiple VHL tumours’ cohort), 76 patients with a VHL disease as described in the literature (‘VHL-like’ cohort) and 946 patients with a PPGL were screened for E1’ genetic variants.ResultsSix different genetic variants in E1' were detected in 12 patients. Two were classified as pathogenic, 3 as variants of unknown significance and 1 as benign. The rs139622356 was found in seven unrelated patients but described in only 16 patients out of the 31 390 of the Genome Aggregation Database (pConclusionsVHL E1’ cryptic exon mutations contribute to 1.32% (1/76) of ‘VHL-like’ cohort and to 0.11% (1/946) of PPGL cohort and should be screened in patients with clinical suspicion of VHL, and added to panels for Next Generation Sequencing (NGS) diagnostic testing of hereditary PPGL. Our data highlight the importance of studying variants identified in deep intronic sequences, which would have been missed by examining only coding sequences of genes/exomes. These variants will likely be more frequently detected and studied with the upcoming implementation of whole-genome sequencing into clinical practice.

Background 1p/19q-codeleted anaplastic gliomas have variable clinical behavior. We have recently shown that the common 9p21.3 allelic loss is an independent prognostic factor in this tumor type. The aim of this study is to identify less frequent genomic copy number variations (CNVs) with clinical importance that may shed light on molecular oncogenesis of this tumor type. Materials and Methods A cohort of 197 patients with anaplastic oligodendroglioma was collected as part of the French POLA network. Clinical, pathological, and molecular information was recorded. CNV analysis was performed using single-nucleotide polymorphism arrays. Computational biology and feature selection based on the random forests method were used to identify CNV events associated with overall survival and other clinical-pathological variables. Results Recurrent chromosomal events were identified in chromosomes 4, 9, and 11. Forty-six focal amplification events and 22 focal deletion events were identified. Twenty-four focal CNV areas were associated with survival, and five of them were significantly associated with survival after multivariable analysis. Nine out of 24 CNV events were validated using an external cohort of The Cancer Genome Atlas. Five of the validated events contain a cancer-related gene or microRNA: CDKN2A deletion, SS18L1 amplification, RHOA/MIR191 copy-neutral loss of heterozygosity, FGFR3 amplification, and ARNT amplification. The CNV profile contributes to better survival prediction compared with clinical-based risk assessment. Conclusion Several recurrent CNV events, detected in anaplastic oligodendroglioma, enable better survival prediction. More importantly, they help in identifying potential genes for understanding oncogenesis and for personalized therapy. Implications for Practice Genomic analysis of 197 anaplastic oligodendroglioma tumors reveals recurrent somatic copy number variation areas that may help in understanding oncogenesis and target identification for precision medicine. A machine learning multivariable model built using this genomic information enables better survival prediction.

We aimed to describe the characteristics, patterns of care and predictive geriatric factors of elderly patients with IDH-mutant (IDHm) high-grade gliomas (HGG) included in the French POLA network, dedicated to HGG (including 68% of IDHm HGG). For IDHm HGG patients over the age of 70 years, geriatric features were collected: G8 score items (appetite, weight loss, mobility, neuropsychological disorders, body mass index, medications, self-rated health, age), Activities and Instrumental Activities of Daily Living (ADL, IADL) scores, Charlson’s comorbidity Index (CCI) and biological markers. Out of the 1433 HGG patients included in the POLA Network, 119 (8.3%) occurred in patients ≥ 70 years. Among them, 39 presented with IDHm HGG. Of these 39 patients, estimated G8 score was ≤ 14/17 for 16 patients (64%), ADL score was < 6 for 33.3%, IADL score was < 4 for 47% and CCI was ≥ 5 for 72%. Regarding treatment feasibility, 6 of the 19 patients treated by temozolomide prematurely discontinued chemotherapy including 2 for toxicity and 4 for progression. Five of the 10 patients treated by PCV prematurely discontinued chemotherapy, all for toxicity. In multivariate analysis, loss of mobility (p=0.018; p=0.008), severe neuropsychological disorders (p=0.005; p=0.047), body mass index < 21 kg/m2 (p=0.002; p=0.006) and ADL score < 6 (p=0.002; p=0.01) were significantly predictive of poor PFS and OS. Then we generated a specific brain geriatric score including these four items with a sensibility, specificity and AUC for long term survivor (≥ 48 months) of 100%, 83% and 0.948 respectively. Using a cutoff of < 10/13, this score was significantly correlated to PFS and OS (p< 0.001 both). In conclusion, geriatric predictive factors may contribute to the elderly management improvement: the brain geriatric score must now be validated in a prospective independent cohort including IDHm and IDHwt elderly patients.

BACKGROUND There is a need to develop new treatments in IDH-mutant high-grade gliomas recurring after radiotherapy and chemotherapy. Based on preclinical studies showing that IDH-mutant tumors could be vulnerable to PARP inhibition we launched a phase II study to test the efficacy of olaparib (Lynparza) monotherapy in this population. METHODS Adults with recurrent high-grade IDH-mutant gliomas after radiotherapy and at least one line of alkylating chemotherapy (PCV or TMZ), KPS > 60, normal organ function were enrolled. The primary endpoint was 6 months PFS according to RANO criteria. Patients were treated with olaparib 300 mg twice daily. We used a single-stage Fleming design with p0 = 30%, p1 = 50%, a type I unilateral error rate of 5% and a power of 80%. RESULTS 35 patients with recurrent IDH-mutant gliomas (IDH1R132H-mutant n = 32, other IDH mutation n = 3, 1p/19 codeleted n = 16, 1p/19q non-codeleted n = 14) were enrolled (malignantly transformed low-grade gliomas n = 21, anaplastic gliomas n = 8, glioblastomas n = 6). Median time since diagnosis was 7.4 years (1–22 years), median time since radiotherapy was 2.8 years (0.6–18 years), median number of previous chemotherapy lines was 2 (1–5). With a median follow-up of 11 months, 30 patients had stopped treatment due to tumor progression and 2 patients were still on treatment 16 to 18 months after treatment start. At 6 months, 11/35 patients were progression-free (31 %). According to RANO criteria, based on local investigator analysis, 2 patients (5%) had a partial response and 14 patients a stable disease (37%) with a median duration of response of 9 months (4–18+). Median PFS and OS were 2.3 and 15.9 months and were similar in 1p/19q codeleted and non-codeleted patients. A grade 3 olaparib-related adverse event was observed in 5 patients (14%, lymphopenia n = 3, fatigue n = 2, diarrhea n = 1) and a grade 2 in 15 patients (43%), most frequently consisting in fatigue (23%), gastrointestinal disorders (20%) and lymphopenia (20%). No patient definitively stopped olaparib due to side effects. CONCLUSIONS In this heavily pre-treated population of recurrent IDH-mutant gliomas, olaparib monotherapy was well tolerated and resulted in some activity supporting its evaluation in association with alkylating chemotherapy in recurrent IDH-mutant gliomas in future studies.

BACKGROUND Hypermutation is an emerging biomarker for predicting response to immunotherapy in cancer patients, however its clinical value in gliomas is not established. We sought to assess the determinants of hypermutation in gliomas, and its value for predicting response to standard of care and immune checkpoint blockade (ICB). METHODS We performed comprehensive genomic characterization of 2,420 clinically annotated gliomas. We assessed the clinical and molecular characteristics associated with hypermutation and relationships between hypermutation and response to cancer treatments. RESULTS Hypermutation occurred predominantly as an adaptive resistance mechanism to temozolomide in gliomas and was most prevalent in recurrent gliomas with MGMTpromoter methylation (33.8%), IDH1/2mutation (41.0%) or 1p/19q co-deletion (59.5%). Hypermutation was almost always associated with molecular defects in DNA mismatch repair (MMR), and was associated with shorter survival after its appearance based on multivariate analysis (hazard ratio 1.91; 95% CI 1.24–2.94; P=0.004). The molecular mechanisms whereby gliomas undergo hypermutation during therapy with alkylating agents were dissected using patient-derived glioma models in vitro and in vivo. Outcomes of hypermutated gliomas treated with immune checkpoint blockade or with standard of care agents will be presented at the conference. CONCLUSIONS Using the largest set of hypermutated gliomas described to date, this study establishes that mutational burden and mutation signatures are clinically and biologically significant biomarkers that can be used to predict therapy response and guide treatment decisions in gliomas

BACKGROUND About 10% of IDH-mutant gliomas harbor non-canonical IDH mutations (non-R132H IDH1 and IDH2 mutations). The aim of the present study was to analyze the characteristics of these gliomas in comparison to those of IDH1 R132H mutant gliomas. MATERIAL AND METHODS We retrospectively analyzed the characteristics of a multicentric series of 161 gliomas with non-canonical IDH mutations and compared them to those of consecutive series of 109 IDH1 R132H mutant gliomas. Medical, radiological and pathological were reviewed. RESULTS Median age at diagnosis was 35 years in gliomas with a non-canonical IDH1 mutation, 42 years in those with an IDH2 mutation and 44 years in those with an IDH1R132H mutation. A familial history of cancer was more frequent in gliomas with a non-canonical IDH mutation than in those with an IDH1 R132H mutation (22,3% vs 5,5%, p CONCLUSION Gliomas with non-canonical IDH mutations are associated with distinct clinical, radiological and histological characteristics. Their prognosis, however, is similar to that of gliomas with canonical IDH mutations.

Background The 2016 WHO classification of the central nervous system tumors stratifies IDH-mutant gliomas into two major groups depending on the presence or absence of 1p/19q-codeletion. However, the grading system remains unchanged and it is now controversial whether it can be still applied to this updated molecular classification. Methods In a large cohort of 911 high grade IDH-mutant gliomas from the French national POLA network (including 428 IDH-mutant gliomas without 1p/19q-codeletion and 483 anaplastic oligodendrogliomas, IDH-mutant and 1p/19q-codeleted), we investigated the prognostic value of CDKN2A gene homozygous deletion as well as WHO grading criteria (mitoses, microvascular proliferation and necrosis). In addition, we also searched for other retinoblastoma pathway gene alterations (CDK4 amplification and RB1 homozygous deletion) in a subset of patients. CDKN2A homozygous deletion was also searched in an independent series of 40 grade II IDH-mutant gliomas. Results CDKN2A homozygous deletion was associated with dismal outcome among IDH-mutant gliomas lacking 1p/19q-codeletion (p Conclusions Our study pointed out the utmost relevance of CDKN2A homozygous deletion as an adverse prognostic factor in the two broad categories of IDH-mutant gliomas stratified on 1p/19q-codeletion and suggest to refine the grading of these tumors.

Purpose: The blood–brain barrier (BBB) limits the efficacy of drug therapies for glioblastoma (GBM). Preclinical data indicate that low-intensity pulsed ultrasound (LIPU) can transiently disrupt the BBB and increase intracerebral drug concentrations. Patients and Methods: A first-in-man, single-arm, single-center trial (NCT02253212) was initiated to investigate the transient disruption of the BBB in patients with recurrent GBM. Patients were implanted with a 1-MHz, 11.5-mm diameter cranial ultrasound device (SonoCloud-1, CarThera). The device was activated monthly to transiently disrupt the BBB before intravenous carboplatin chemotherapy. Results: Between 2014 and 2016, 21 patients were registered for the study and implanted with the SonoCloud-1; 19 patients received at least one sonication. In 65 ultrasound sessions, BBB disruption was visible on T1w MRI for 52 sonications. Treatment-related adverse events observed were transient and manageable: a transient edema at H1 and at D15. No carboplatin-related neurotoxicity was observed. Patients with no or poor BBB disruption (n = 8) visible on MRI had a median progression-free survival (PFS) of 2.73 months, and a median overall survival (OS) of 8.64 months. Patients with clear BBB disruption (n = 11) had a median PFS of 4.11 months, and a median OS of 12.94 months. Conclusions: SonoCloud-1 treatments were well tolerated and may increase the effectiveness of systemic drug therapies, such as carboplatin, in the brain without inducing neurotoxicity. See related commentary by Sonabend and Stupp, p. 3750

High tumor mutational burden (hypermutation) is observed in some gliomas; however, its mechanisms of development and whether it predicts immunotherapy response are poorly understood. Here, we comprehensively analyze the molecular determinants of mutational burden and signatures in 10,294 gliomas including AACR Project GENIE and institutional datasets. We delineate two main pathways to hypermutation: a de novo pathway associated with constitutional defects in DNA polymerase and mismatch repair (MMR) genes, and a more common post-treatment pathway associated with acquired resistance driven by MMR defects in chemotherapy-sensitive gliomas that recur after temozolomide treatment. Experimentally, the mutational signature of post-treatment hypermutated gliomas was only recapitulated by temozolomide-induced damage in cells harboring MMR deficiency. MMR-deficient gliomas exhibited unique features including the lack of prominent T-cell infiltrates, extensive intratumoral heterogeneity, poor survival and low response rate to PD-1 blockade. Moreover, while microsatellite instability in MMR-deficient gliomas was not detected by bulk analyses, single-cell whole-genome sequencing of post-treatment hypermutated glioma cells demonstrated microsatellite mutations. This study shows that chemotherapy can drive acquisition of hypermutated populations without promoting response to PD-1 blockade and supports diagnostic use of mutational burden and signatures in cancer. Citation Format: Mehdi Touat, Yvonne Y. Li, Adam N. Boynton, Liam F. Spurr, Bryan Iorgulescu, Craig L. Bohrson, Isidro Cortes-Ciriano, Jack E. Geduldig, Kristine Pelton, Mary J. Lim-Fat, Sangita Pal, Shakti H. Ramkissoon, Frank Dubois, Charlotte Bellamy, Naomi Currimjee, Kenin Qian, Seth Malinowski, Aniket Shetty, Kin-Hoe Chow, Maïté Verreault, Erell Guillerm, Samy Ammari, Frédéric Beuvon, Karima Mokhtari, Agusti Alentorn, Caroline Dehais, Caroline Houillier, Florence Laigle-Donadey, Dimitri Psimaras, Alexandre Carpentier, Philippe Cornu, Laurent Capelle, Bertrand Mathon, Jill S. Barnholtz-Sloan, Arnab Chakravarti, Wenya L. Bi, Garrett M. Frampton, Marc Sanson, Brian M. Alexander, Andrew Cherniack, Patrick Y. Wen, David A. Reardon, Aurelien Marabelle, Peter J. Park, Ahmed Idbaih, Rameen Beroukhim, Pratiti Bandopadhayay, Franck Bielle, Keith L. Ligon. Mechanisms and therapeutic implications of hypermutation in gliomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5705.

and the POLA network; International audience; Diffuse gliomas are classified according to the 2016 WHO Classification of Tumors of the Central Nervous System, which now defines entities by both histology and molecular features. Somatostatin receptor subtype 2A (SSTR2A) expression has been reported in various solid tumors as associated with favorable outcomes. Its expression has been reported in gliomas with uncertain results regarding its prognostic value. The objective of this study was to assess the prognostic impact of SSTR2A protein expression in a large cohort of grade III and IV gliomas classified according to the updated 2016 WHO classification. We further validated our result with an independent cohort of low grade glioma using dataset generated by The Cancer Genome Atlas (TCGA) Research Network. We analyzed clinical and molecular data from 575 patients. SSTR2A protein expression was evaluated using immunohistochemistry on tissue microarrays. High expression of SSTR2A protein associated with the anaplastic oligodendroglioma IDH-mutant and 1p/19q-codeleted subgroup (p < 0.001). Among these tumors, SSTR2A protein expression was significantly associated with a lower proliferative index, the absence of microvascular proliferation and the absence of necrosis (p < 0.001). Furthermore SSTR2A protein expression associated with better overall survival (p = 0.007) and progression-free survival (p = 0.01) in both univariate and multivariate analysis when adjusted by the age, the presence of necrosis and the mitotic index. Similar results were obtained regarding SSTR2 mRNA expression in the TCGA low grade glioma, subtype IDH-mutant and 1p/19q-codeleted, dataset. SSTR2A might represent an attractive biomarker and therapeutic target in anaplastic oligodendroglioma IDH-mutant and 1p/19q-codeleted specific subgroup. Understanding the implicated molecular pathways may represent a step forward to improve therapeutic approaches.

Objectives: We aimed to study the potential clinical relevance of 9p allelic loss, with or without copy number variation, in 1p/19q codeleted anaplastic oligodendroglial tumors (AOTs). Methods: This study enrolled 216 patients with 1p/19q codeleted AOT. The prognostic value of 9p allelic loss was investigated using a French nation-wide prospective registry, POLA (prise en charge des tumeurs oligodendrogliales anaplasiques) and high-density single nucleotide polymorphism arrays. We validated our results using the Repository of Molecular Brain Neoplasia Data (REMBRANDT) dataset. Results: The minimal common region of allelic loss in chromosome arm 9p was 9p21.3. Allelic loss of 9p21.3, detected in 41.7% of tumors, was associated with shorter progression-free and overall survival rates in univariate ( p = 0.008 and p p = 0.009 and p = 0.009, respectively). This finding was validated in the REMBRANDT dataset in univariate and multivariate analysis ( p = 0.01 and p = 0.01, respectively). Conclusion: Our study highlights a novel potential prognostic biomarker in 1p/19q codeleted AOT. Further prospective studies are warranted to investigate our finding.

BACKGROUND: Although major advances have been accomplished over the last years in their characterization, 1p/19q-codeleted anaplastic gliomas have variable clinical behavior and mysterious 1p/19q-codeletion “driven” molecular oncogenesis. We have recently shown that the most common alteration (i.e. 9p21.3 allelic loss detected in 42% of cases) is an independent prognostic factor in this tumor type. However, less frequent Genomic Copy Number Variations (CNV) may also have clinical value and may shed light on molecular oncogenesis of this tumor type. METHODS: A cohort of 197, 1p/19q-codeleted grade III gliomas was collected as part of the French POLA network. Clinical, pathological and molecular information were recorded and the patients were clinically followed up. CNV analysis was performed using SNP arrays. Computational biology and machine learning analysis were applied to identify less common additional CNV events associated with overall survival and other clinical-pathological variables Results: Recurrent chromosomal events were identified in chromosomes 4, 9, and 11. 46 focal amplification events and 22 focal deletion events were identified. 12 of the focal events overlapped with known cancer related genomic regions. 24 focal CNV areas were associated with survival and five of them were significantly associated with survival after multivariate analysis. 9/24 signals, detected in 3 to 26 percent of patients, were validated using an external cohort of gliomas of the Cancer Genome Atlas. Five of the validated signals contain a cancer related gene or MIR: CDKN2A deletion, SS18L1 amplification, RHOA/MIR191 copy-neutral loss of heterozigosity, FGFR3 amplification, and ARNT amplification. The CNV profile enables better survival prediction compared to clinical risk assessment. Conclusions: Several recurrent CNV events are characteristics for 1p/19q-codeleted grade III gliomas. These genomic regions are associated with survival and enable better survival prediction. More important, they may help identifying potential genes for understanding oncogenesis and for personalized therapy.

BACKGROUND Circulating proteins released by tumor cells have recently been investigated as potential single surrogate biomarkers for glioblastoma multiforme (GBM). The aim of the current hypothesis-generating study was to evaluate the diagnostic and prognostic role of preoperative insulin-like growth factor-binding protein 2 (IGFBP-2), chitinase-3-like protein 1 (YKL-40), and glial fibrillary acidic protein (GFAP) plasma levels in patients with GBM, both as single markers and as a combined profile. METHODS Plasma samples from 111 patients with GBM and a subset of 40 patients with nonglial brain tumors were obtained preoperatively. Plasma from 99 healthy controls was also analyzed. IGFBP-2, YKL-40, and GFAP levels were determined using enzyme-linked immunoadsorbent assay tests. Their association with histological and radiological variables was assessed. RESULTS Circulating levels of all 3 proteins were found to be significantly higher in patients with GBM compared with healthy controls (P < .01). Only YKL-40 and GFAP were found to demonstrate significant differences between patients with GBM and nonglial brain tumors (P = .04). GFAP was undetectable (

Introduction: Despite the identification in the early 90’s that anaplastic oligodendroglial tumours (AOT) were chemosensitive, the role and optimal timing of chemotherapy in these tumours had remained subject of debate until recently. Areas covered: Based on the long-term results of two Phase III trials – one by the Radiation Therapy Oncology Group (RTOG) and the other by the European Organization for Research and Treatment of Cancer (EORTC) – current and future treatment options for AOT are reviewed. Expert opinion: The up-dated results of the RTOG and EORTC trials have defined radiotherapy (RT) plus PCV (Procarbazine, CCNU, Vincristine) as the new standard of care for 1p/19q co-deleted AOT. In these tumors, both studies demonstrated that initial treatment with RT plus PCV was associated with an important increase of median overall survival compared to RT alone. In addition, the up-dated results of the RTOG trial suggest that non co-deleted isocitrate dehydrogenase (IDH) mutated AOT, in contrast to IDH w...

Background The characteristics of elderly patients with IDH-mutant (IDHm) high-grade gliomas (HGG) remain to be described. This study aims to describe characteristics and patterns of care of elderly patients with IDHm HGG included in the French POLA network dedicated to HGG. Methods The characteristics and patterns of care of elderly (≥70 years) patients IDHm HGG were compared to those of younger patients ( Results Out of the 1433 HGG patients included, 119 (8.3%) occurred in elderly patients. Histology consisted of 1p/19q codeleted anaplastic oligodendroglioma (71.8%), anaplastic IDHm astrocytomas (12.8%) and IDHm glioblastoma (15.4%). Median age at diagnosis was 74 years (70.2-87.1), median Karnofsky Performans Status (KPS) was 80 (50-100). Treatments consisted of a wait and scan policy (7.7%), radiotherapy (RT) alone (7.7%), chemotherapy (CT) alone (41%), RT-CT (RT-TMZ: 25.6%, RT-PCV: 15.4%) or palliative care (2.6%). The clinical, radiological and histological presentations of elderly patients IDHm HGG were different from those of elderly patients IDHwt HGG. Compared to elderly patients IDHwt HGG, elderly patients IDHm were less frequently associated with cognitive impairment (p = 0.045), contrast enhancement (p = 0.01) and had a lower proliferative index (Ki67) (p = 0.005). In contrast, there was no difference regarding clinical, radiological and histological presentations of elderly and younger patients IDHm HGG but their management was different. Elderly patients IDHm less frequently underwent gross total resection (p = 0.002) and radiotherapy (p Conclusions IDHm HGG in elderly show prolonged survival. However, their poorer outcome compared to younger IDHm gliomas may results from patient or tumor characteristics or from under-treatment, suggesting a role for geriatric assessment. Legal entity responsible for the study French POLA network. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

BACKGROUND Lower-grade gliomas (LGG) are divided into three histo-molecular groups: i) IDH-wildtype, ii) IDH mutant and 1p19q intact and iii) IDH mutant and 1p19q co-deleted. The current classification has improved the clinical stratification and its reproducibility. However, LGGs are still associated with an important degree of clinical heterogeneity. We sought to analyze the cross-talk between the spatial distribution and the quantitative imaging features (radiomics) with the clinical evolution and their molecular background (radiogenomics). MATERIAL AND METHODS We performed a retrospective multicentric study from 4 cohorts of high-grades gliomas (POLA Network, TCGA, REMBRANDT and LGG-1p19q), totaling 900 gliomas. We performed N4 and WhiteStripe imaging corrections to standardize MRI intensities. We used ITK-SNAP to obtain a mask of the different habitats of the tumor. Then we used PyRadiomics to obtain 2616 radiomic features per sample. We used plsRcox for fitting several Cox model in high-dimensional settings. We assessed the performance of the difference Cox model with the Harrel’s concordance index. We used a Sparse Canonical Correlation analysis to analyze the spatial distribution of the tumors. RESULTS Radiomics features allow identification in an unsupervised manner IDH-mutant gliomas with a median AUC of 0.96 [0.92–0.98]. Interestingly, in the analysis of survival, radiomics features provided additional information to clinical or genetics covariates and the model with only radiomics features obtained a C-Index of 0.78 [0.72–0.82]. In addition, survival model with the best performance in the prediction of overall survival was the one combining radiomics, clinics and genetics features with a C-Index 0.85 [0.82–0.92] and was validated in the other cohorts. The analysis of spatial distribution showed a very strong distribution of 1p19q co-deleted oligodendrogliomas in the frontal lobes. CONCLUSION Radiomics features may provide additional relevant clinical information by improving the prognosis of LGG. Radiomics allow non-invasive prediction of the most relevant molecular alterations of LGG.

BACKGROUND Although patients with 1p/19q codeleted anaplastic oligodendrogliomas (AO) usually have a prolonged survival, some patients have a poorer outcome. The aim of the present study was to analyze their characteristics. MATERIAL AND METHODS The characteristics of AO patients with a survival < 5 years included in the POLA network were analyzed and compared to those of AO patients with a survival > 5 years. RESULTS In January 2019, among the 519 patients AO patients included in the POLA network, 55 patients were short-term survivors and 146 patients had a survival > 5 years. Among the 55 AO short-term survivors, 44 patients (80%) died from tumor progression and 11 patients (20%) from another cause (suicide n=2, toxicity n=2, intercurrent disease n=6, other n=1). Compared to > 5 years survivors, short-term survivors were older (57 years vs 48 years, p 5 years survivors, short-term survivors less frequently underwent a surgical resection (64% vs 89% p CONCLUSION AO short-term survivors are associated with distinct clinical, radiological, histological and molecular characteristics at diagnosis.

2041 Background: Grade II and III Oligodendroglioma associate mutations of isocitrate deshydrogenase 1 or 2 genes and the whole-arm chromosomal loss of 1p and 19q and have a better prognosis than other gliomas. However, even if the preferred treatment consists of a combination of radiotherapy (RT) and chemotherapy, some patients will less respond to this treatment and will relapse faster , in part because of an heterogeneity in the response to RT. In the aim to identify factors of response to RT, we analyzed clinical and molecular data of patients with grade II-III oligodendroglioma exclusively treated with RT in the POLA cohort. Methods: Gene expression profiles on Affymetrix expression arrays of patients from the POLA cohort with co-deleted 1p/19q grade II/II gliomas treated by exclusive RT were used to identify a gene expression set predictive of radiation sensitivity. The primary endpoint was the progression free survival (PFS), defined as the time from treatment start until progression or death. A supervised approach with penalized regression was applied to select most informative predictors, and then a risk score was created based on the linear predictor given by the multivariable model. Results: Forty-five patients corresponded to the study criteria, with a median age at diagnosis of 45 (range 23- 64). The supervised approach allowed identifying a three-gene prognostic set including Semaphorin -3C (SEMA3C), Neuronal Pentraxin 2 (NPTX2 ) and the Metabotropic Glutamate Receptor 5 (GRM5), involved in proliferation, migration and inflammation. The risk score associated to these three genes was statistically associated to PFS (HR = 2.72, p = 0.00005) and remains significant when adjusted on clinical covariates age at diagnosis, necrosis, endothelial proliferation and type of surgery (complete, partial or subtotal surgery) (HRadj = 2.36, p = 0.001). Conclusions: We report an independent three genes SEMA3C-NPTX2-GRM5 risk score signature of response to radiotherapy in patients with oligodendroglioma, which highlights the heterogeneous response in this reputed good prognosis population. This signature could help in determining the adapted treatment as well as potential new targets to address.

BACKGROUND: The aim of this study was to correlate MRI features and molecular characteristics in anaplastic oligodendrogliomas (AOs). METHODS: The MRI characteristics of 50 AO patients enrolled in the French national network for high-grade oligodendroglial tumors were analyzed. The genomic profiles and IDH mutational statuses were assessed using high-resolution single-nucleotide polymorphism arrays and direct sequencing, respectively. The gene expression profiles of 25 1p/19q-codeleted AOs were studied on Affymetrix expression arrays. RESULTS: Most of the cases were frontal lobe contrast-enhanced tumors (52%), but the radiological presentations of these cases were heterogeneous, ranging from low-grade glioma-like aspects (26%) to glioblastoma-like aspects (22%). The 1p/19q codeletion (n = 39) was associated with locations in the frontal lobe (P = .001), with heterogeneous intratumoral signal intensities (P = .003) and with no or nonmeasurable contrast enhancements (P = .01). The IDH wild-type AOs (n = 7) more frequently displayed ringlike contrast enhancements (P = .03) and were more frequently located outside of the frontal lobe (P = .01). However, no specific imaging pattern could be identified for the 1p/19q-codeleted AO or the IDH-mutated AO. Within the 1p/19q-codeleted AO, the contrast enhancement was associated with larger tumor volumes (P = .001), chromosome 9p loss and CDKN2A loss (P = .006), genomic instability (P = .03), and angiogenesis-related gene expression (P < .001), particularly for vascular endothelial growth factor A and angiopoietin 2. CONCLUSION: In AOs, the 1p/19q codeletion and the IDH mutation are associated with preferential (but not with specific) imaging characteristics. Within 1p/19q-codeleted AO, imaging heterogeneity is related to additional molecular alterations, especially chromosome 9p loss, which is associated with contrast enhancement and larger tumor volume.

The new WHO classification of diffuse gliomas has been refined and now includes the 1p/19q codeletion, IDH1/2 mutation, and histone H3-K27M mutation. Our objective was to assess the prognostic value of the updated 2016 WHO classification in the French POLA cohort. All cases of high-grade oligodendroglial tumors sent for central pathological review and included into the French nationwide POLA cohort were reclassified according to the updated 4th WHO classification. In total, 1041 patients were included, with a median age at diagnosis of 50.4 years (range 17.1–84.4). Based on the new histomolecular classification, diagnoses included anaplastic oligodendroglioma IDH mutant and 1p/19q-codeleted (32.5 %), anaplastic astrocytoma IDH mutant (IDH mut) (11.0 %), anaplastic astrocytoma IDH wild type (IDH wt) (5.3 %), glioblastoma IDH mut (17.1 %), and glioblastoma IDH wt (33.2 %). Ten patients presented with a diffuse midline tumor, H3 K27M mutant. The new WHO classification was prognostic for progression-free survival (PFS) and overall survival (OS) (p

BACKGROUND: Low-grade gliomas (LGG) are divided into three histo-molecular groups: i) IDHwt, ii) IDHmut and 1p19q intact and iii) 1p19q co-deleted with IDH1 mutation. The current classification has improved the clinical stratification and its reproducibility. However, LGGs are still associated with an important degree of clinical heterogeneity.We sough to analyze the genomic and genetic heterogeneity by re-analyzing next-generation sequencing data of two different cohorts of LGG to dissect the potential role of clonal architecture on the clinical evolution of LGG. MATERIAL AND METHODS: We have re-analyzed whole-exome sequencing (WES) using LGG TCGA dataset and a cohort of 40 LGG analyzed by WES from the POLA Network. We have obtained the clonal architecture, the mutation burden, the number of clones, the clonal and subclonal distribution of genetic and genomic alterations and the distribution of the somatic signatures. In addition, we have also analyzed 5 1p19q co-deleted samples at different timepoints to further dissect the clonal evolution of this entity. RESULTS: As expected, the mutation burden of LGG is low (median somatic mutation per sample 34). Surprisingly, the number the subclones was higher in the 1p19q co-deleted subgroup.LGG were enriched in somatic signatures associated with hydrolytic deamination of methylated CpG and with deficiency of mismatch repair. Interestingly, only within 1p19q co-deleted gliomas, the number of subclones, the mutant-allele tumor heterogeneity (MATH) score and the signature associated with hydrolytic deamination of methylated CpGwere associated with poorer outcome in univariate analysis. Finally, only the enrichment of the mutational signature associated with hydrolytic deamination of methylated CpG had prognostic impact in 1p19q co-deleted LGG in Cox multivariate analysis afteradjusting by age, mutational clones number, MATH score and loss of CDKN2A loss. CONCLUSION: The clonal architecture of LGG may provide additional clinical relevant data within 1p19q co-deleted tumors. The enrichment of a somatic signature associated with hydrolytic deamination of methylated CpG is independently associated with poor overall survival.

Optimal treatment of anaplastic oligodendrog- lial tumors (AOT) in elderly patients is debatable. We report a retrospective study of 44 consecutive patients aged 70 years or older (median age: 74 years; median Karnofsky performance status (KPS): 70) treated with up-front che- motherapy using temozolomide (TMZ) at conventional doses until tumor progression. O 6 -methylguanine-DNA methyltransferase promoter (MGMTP) methylation was assessed in 38 patients. Of the 41 evaluable patients, partial response (PR) was seen in 13 (32%) patients, 17 (41%) patients achieved stable disease, while the disease pro- gressed in 11 (27%) patients. Median progression-free survival (PFS) and overall survival (OS) were 6.9 and 12.4 months, respectively. Hematoxicity grades 3-4 occurred in nine patients (20%). MGMTP was methylated in 50% of patients and was associated with both longer PFS (8.7 versus 5.7 months, P = 0.01) and longer OS (16.1 versus 12.4 months, P = 0.05). The rate of responders to chemotherapy was similar in MGMTP-methylated (38%) and in MGMTP-unmethylated patients (31%), but duration of response was significantly longer in responders with methylated MGMTP than in responders with unmethylated MGMTP (16.1 versus 9.6 months, P = 0.0004). This study demonstrates that a substantial number of elderly patients with AOT can achieve prolonged survival with up-front chemotherapy using TMZ. Further investigation is needed to determine whether this treatment is preferable to initial radiation therapy.

2016Background: The BBB limits the efficacy of many chemotherapies in GBM patients by blocking the passage of drugs to the brain. Two to four minutes of LIPU in combination with injection of micron...

L’interet pour les lymphomes primitifs du systeme nerveux central (LPSNC) est lie a l’augmentation importante de son incidence observee aussi bien chez l’immunocompetent que chez l’immunodeprime et aux progres realises ces dernieres annees dans le pronostic de ces tumeurs. Le traitement de reference repose sur l’adjonction d’une chimiotherapie (CT) a base de methotrexate (MTX) intraveineux a forte dose a la radiotherapie (RT) encephalique, autorisant une mediane de survie de trois a quatre ans et un taux de longs survivants de 30 %. Chez les patients âges (> 60 ans) qui constituent la moitie des patients, la RT de consolidation n’est plus recommandee en cas d’obtention d’une remission complete avec la CT seule en raison d’un haut risque de leucoencephalopathie. L’intensification de la CT avec greffe de cellule souche peripherique constitue une perspective therapeutique tres prometteuse dans les recidives ou, eventuellement, en alternative a la RT dans le traitement initial.

BACKGROUND. There is a need to improve the current, controversial, and poorly reproducible classification of anaplastic gliomas, which represent a highly heterogeneous entity in terms of survival. METHODS. The impact of the most common genetic alterations on survival was investigated based on 156 anaplastic gliomas: Among the patients who were included, the gender ratio was 1.32, the median age was 45.5 years (range, 20–83 years), and the median Karnofsky performance status was 70 (range, 40–100). Genetic analysis included a search for loss of heterozygosity (LOH) on chromosomes 1p and 19q; amplification of chromosomes 9p and 10q and of the epidermal growth factor receptor (EGFR), cyclin-dependent kinase 4 (CDK4) and mouse double-minute (MDM2) genes; and p53 expression. RESULTS. The median survival was 33.5 months, and the median progression-free survival was 15.8 months. In a univariate analysis, LOH on 1p and 19q was correlated with longer survival, whereas p53 expression, LOH on 9p, LOH on 10q, amplified EGFR, and deleted CDKN2A were correlated with shorter survival. LOH on 1p and 19q were associated with oligodendrogliomas, LOH on 10q was related to EGFR amplification, and LOH on 1p and 19q was mutually exclusive with EGFR amplification and LOH on 10q. In a multivariate analysis, the significant prognostic factors were age, histology, LOH on 1p and 19q, and P16/CDKN2A deletion. Recursive partitioning analysis (RPA) divided the whole group hierarchically into 3 distinct prognostic subgroups: Group A with 1p19q codeletion (median survival, 98 months), Group B with EGFR amplification (median survival, 17 months), and Group CC (median survival, 31 months), providing a basis for a genetically based prognostic subclassification for patients with Grade III gliomas. CONCLUSIONS. The search for 1p19q codeletion and EGFR receptor amplification provides a simple, clinically relevant prognostic subclassification of grade III gliomas. Cancer 2006. © 2006 American Cancer Society.

2034 Background: The BBB prevents the passage of most drugs from the blood to the brain and may be responsible for the limited efficacy of current chemotherapies in GBM patients. Two to four minutes of LIPU in combination with injection of micron-sized microbubbles has been shown to be a safe method for disrupting the BBB for a duration of 6 hours to increase the passage of drugs such as carboplatin by 5 to 7 fold in normal brain. Methods: Patients with recurrent GBM were implanted with a 1 MHz, 10-mm diameter pulsed ultrasound device in a burr hole during additional debulking surgery or during a dedicated procedure under local anesthesia. Ultrasound dose was escalated using a 3+3 Simon design. The device was activated monthly in combination with injection of a sulfur hexafluoride microbubble to transiently disrupt the BBB in 5 cm3 of the tumor field before IV administration of carboplatin chemotherapy (AUC4-6). Patients received 150-270 seconds of pulsed ultrasound < 1 hour prior to chemotherapy. BBB disruption was visualized using contrast-enhanced T1w MRI, and patients were monitored clinically and with T2, FLAIR, DWI and SWI sequences. Tumor progression was evaluated using the RANO criteria. Results: Nineteen patients were treated by LIPU until tumor progression. In 65 ultrasound sessions, 52 showed BBB disruption. The median number of monthly sonications per patient was 3 and ranged from 1-10. No significant adverse events related to ultrasound sonications were observed. Six patients (31%) had long PFS (19, 20, 35, 38, 40, 52 weeks). When tumor recurrence occurred, it was predominantly outside of the ultrasound sonication field. Conclusions: This trial has demonstrated that LIPU is a safe modality for disrupting the BBB in GBM patients and may increase the effectiveness of drug therapies in the brain. The sonication of larger volumes of brain may further increase the effectiveness of this therapy in patients with GBM. Clinical trial information: NCT02253212.

BACKGROUND: The aim of this study was to correlate histological features and molecular characteristics in anaplastic oligodendrogliomas (AO). METHODS: The histological characteristics of 203 AO patients enrolled in the French national network POLA were analyzed. The genomic profiles of 191 cases were studied using genomic arrays. IDH mutational status was assessed by immunohistochemistry and direct sequencing. RESULTS: 1p/19q co-deletion was present in 79% of cases and was associated with alpha-internexin expression (p < 10-4), IDH1/2 mutation (p < 10-4), chromosome 4 loss (p < 10-3), and better overall survival (p < 10-4). Based on mitotic index, microvascular proliferation (MVP) and necrosis, 3 groups of 1p/19q co-deleted AO were identified: AO with more than 5 mitoses per 10-HPF, no MVP and no necrosis, (1), AO with MVP and no necrosis (2) and AO with MVP and necrosis (3). Compared to group 1, group 2 and 3 AO had a higher mean Ki-67 proliferation index and a higher rate of 9p and 9q losses. Compared to group 2, group 3 AO had a higher number of chromosomal alterations including chromosome 4 loss. In the subgroup of 157 1p/19q co-deleted AO, chromosomal instability was associated with shorter progression free survival (p = 0.024) and shorter overall survival (p = 0.023). CONCLUSIONS: The present study shows that oligodendroglioma with classic histological features remains a molecularly heterogeneous entity and should be stratified according to 1p/19q status because of its major prognostic relevance. Moreover, 1p/19q co-deleted AO are also heterogeneous. Interestingly, mitotic index, MVP and necrosis help to classify them into three groups associated with distinct genomic alterations.

2015Background: The upcoming WHO classification of gliomas will be refined taking into account the robust molecular alterations of gliomagenesis: the 1p19q codeletion and IDH1/2mutations. Methods: ...

International audience; Anaplastic oligodendrogliomas (AOD) are rare glial tumors in adults with relative homogeneous clinical, radiological and histological features at the time of diagnosis but dramatically various clinical courses. Studies have identified several molecular abnormalities with clinical or biological relevance to AOD (e.g. t(1;19)(q10;p10), IDH1, IDH2, CIC and FUBP1 mutations).To better characterize the clinical and biological behavior of this tumor type, the creation of a national multicentric network, named "Prise en charge des OLigodendrogliomes Anaplasiques (POLA)," has been supported by the Institut National du Cancer (InCA). Newly diagnosed and centrally validated AOD patients and their related biological material (tumor and blood samples) were prospectively included in the POLA clinical database and tissue bank, respectively.At the molecular level, we have conducted a high-resolution single nucleotide polymorphism array analysis, which included 83 patients. Despite a careful central pathological review, AOD have been found to exhibit heterogeneous genomic features. A total of 82% of the tumors exhibited a 1p/19q-co-deletion, while 18% harbor a distinct chromosome pattern. Novel focal abnormalities, including homozygously deleted, amplified and disrupted regions, have been identified. Recurring copy neutral losses of heterozygosity (CNLOH) inducing the modulation of gene expression have also been discovered. CNLOH in the CDKN2A locus was associated with protein silencing in 1/3 of the cases. In addition, FUBP1 homozygous deletion was detected in one case suggesting a putative tumor suppressor role of FUBP1 in AOD.Our study showed that the genomic and pathological analyses of AOD are synergistic in detecting relevant clinical and biological subgroups of AOD.

BACKGROUND: In grade II and codeleted grade III gliomas, the procarbazine-CCNU-vincristine (PCV) combination increase survival when added to radiotherapy as first line treatment, despite the important toxicity of this treatment schedule. Our objective was to analyze the tolerance, feasibility and impact of dose intensity of the PCV regimen on outcome for patients with OG. METHODS: We retrospectively reviewed all grade III OG patients receiving PCV (CCNU:110mg/m2) who were referred to our two institutions. The total dose and dose adaptation, cycle delay, dose intensity, toxicity and premature discontinuation of CCNU were analyzed. Impact of these factors on patient outcome was evaluated. RESULTS: Between 2007 and 2011, 89 patients received PCV. Only 37% completed 6 cycles, whereas 13.4% prematurely discontinued PCV because of toxicity. Cycle delay and dose reduction were observed for 62% and 70% patients, respectively. Grade 3 and 4 toxicities were observed in 38% and 8% patients, respectively. Among patients who did not progress under PCV regimen, by multivariate analysis, premature discontinuation for toxicity was significantly correlated with poor PFS (p = 0.023, Hazard ratio (HR):2.354) and OS (p = 0.021, HR:5.093). By univariate analyses, absence of CCNU dose adaptation was correlated to poor PFS (p = 0.032). For OS, pejorative factors were high total CCNU dose (p = 0.029), absence of cycle delay (p = 0.009), absence of CCNU dose adaptation (p = 0.020) and grade 3/4 toxicities (p = 0.013). High CCNU dose-intensity tended to poorly impact PFS (p = 0.053) and OS (p = 0.112). By multivariate analysis, absence of CCNU dose adaptation remained significant for PFS (p = 0.001), while OS was negatively impacted by the absence of cycle delay (p = 0.049) and grade 3/4 toxicities (p = 0.045). CONCLUSION: Despite the efficacy of the PCV regimen, significant toxicity is associated with this schedule, which appears to impact its feasibility and efficacy. The optimal PCV schedule should be redefined taking into account this finding.

Anaplastic or WHO grade III oligodendrogliomas (AO) are a heterogeneous subgroup of diffuse glial tumors in adults. Three major histomolecular subtypes with clinical relevance have been individualized: (i) 1p/19q co-deleted AO -80% of cases-, (ii) non 1p/19q co-deleted and IDH mutated AO -10% of cases- and (iii) non 1p/19q co-deleted and IDH wild-typeAO -10% of cases-. 1p/19q co-deleted AO, and to a lesser extent IDH mutated AO, have better prognosis and better response to treatment with a median survival of more than 10 years, as shown in two phase III international trials. We have recently shown that loss of heterozygosity (LOH) in chromosome arm 9p, with copy number loss -CL LOH- or without -Copy Neutral LOH- is a frequent event in AO. Interestingly, 9p CN LOH, inducing gene under-expression, has biological significance. In the present study, we address the prognostic value of 9p loss in 1p/19q co-deleted AO. In the present study, 228 AO exhibiting 1p/19q co-deletion were included. All tumors were centrally reviewed in the setting of the French national network for high-grade oligodendroglial tumors (POLA network) that recruits prospectively newly diagnosed anaplastic oligodendroglial tumors. Tumor DNA was analyzed using high-resolution single nucleotide polymorphism array analysis. In the entire series, 70/228 (1/3) harbored 9p loss including CN-LOH, homozygous loss or CL-LOH. 9p loss was associated with a worse prognosis in 1p19q co-deleted AO in univariate analysis (3-years OS of 98% vs. 74%, p < 0.001) whereas PFS at three years was not significantly different (3-years PFS of 88% vs. 66% p = 0.1). After adjustment for age, KPS, and treatment, multivariate analysis demonstrated 9p loss to be an independent prognostic factor for OS, p-value = 0.03, HR = 4.9 [1.2-16], but not for PFS. 1p19q co-deleted AO harboring 9p loss have shorter overall survival compared to their non 9p-lost counterparts in this prospective cohort. Further studies are needed to validate our findings.

The neuronal intermediate filament alpha internexin (INA) is expressed in most gliomas with 1p19q codeletion and could represent a valuable prognostic marker in clinical routine. INA expression was analysed on 409 gliomas and correlated with histology, progression free survival (PFS), overall survival (OS), genomic profile assessed by CGH-array, IDH1/IDH2 mutation and p53 expression. INA was expressed in 59% of grade II oligodendrogliomas (n=73), 45% of grade III oligodendrogliomas (n=133), 15% of grade II oligoastrocytomas (n=61), 12% of grade III oligoastrocytomas (n=41), 23% of glioblastomas with oligodendroglial component (n=31), 0% of grade I astrocytomas (n=3), 0% of grade II astrocytomas (n=14), 6% of grade III astrocytomas (n=17) and 0% of glioblastomas (n=36). INA expression was detected in 85% of gliomas with complete 1p19q codeletion ('true 1p19q signature') (n=85) versus 15% of gliomas without 1p19q codeletion (n=245), including 14% of gliomas with variable/partial 1p19q deletion ('false 1p19q signature') (n=72) (p

The prognosis of low-grade gliomas (LGGs) varies widely, with overall survival (OS) ranging from a few years to decades. Defining reliable prognostic factors in LGGs has been difficult, but the importance of clinical factors, including gender, age, Karnofsky performance status (KPS), symptoms at diagnosis, tumor size, and extent of tumor resection, has been recently recognized.1–4 To date, the only identified molecular alteration of prognostic importance in LGGs is the 1p–19q co-deletion.5,6 Loss of heterozygosity (LOH) on chromosomes 9p and 10q is rare in LGGs. These alterations are classically associated with high-grade tumors (anaplastic gliomas and glioblastomas)7 and have been found to be of prognostic significance in anaplastic gliomas8 but not in glioblastomas.9 In this study, we analyzed the prognostic impact of LOH on 9p and 10q in a series of LGGs.

There is a growing evidence of using Temozolomide as upfront therapy for progressive low grade gliomas. No data exist on the efficacy of nitrosoureas as an alternative to radiotherapy in those patients who progress after Temozolomide. We retrospectively reviewed 30 patients with median age of 46 years. Twenty-one patients had pure oligodendrogliomas. Thirteen patients had a non-enhancing tumor at progression after Temozolomide. The chromosomes 1p/19q were co-deleted in 5 cases and retained in 10 cases. Response rate was 10% (3 minor responses achieved in non-enhancing tumors). Tolerance was acceptable (17% grade III and IV myelosupression). Median PFS was 6.5 months. Median OS from start of salvage treatment was 23.4 months. Tumors without contrast enhancement demonstrated a better prognosis than those with contrast enhancement both in term of PFS (P = 0.0003) and OS (P = 0.0006). Chromosomes 1p/19q codeletion was not predictive for objective response to salvage treatment but correlated with a better PFS (P = 0.02). In conclusion, salvage NU chemotherapy provide disappointing results in TMZ-pretreated low grade gliomas (LGG), which should be treated in priority by conventional radiotherapy especially in LGG that display contrast enhancement at progression.