Prognosis of glioblastoma patients improves significantly over time interrogating historical controls

BACKGROUND

Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time.

METHODS

To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.e. Karnofsky Performance Status -KPS- above 70%) and treated in our department according to the standard of care (SOC) between 2005 and 2018. Patients were divided into two groups according to the year of diagnosis (group 1: from 2005 to 2012; group 2: from 2013 to 2018).

RESULTS

Characteristics of patients and tumors of both groups were very similar regarding confounding factors (age, KPS, MGMT promoter methylation status and treatments). Follow-up time was fixed at 24 months to ensure comparable survival times between both groups. Group 1 patients had a mOS of 19 months ([17.3-21.3]) while mOS of group 2 patients was not reached. The recent period of diagnosis was significantly associated with a longer mOS in univariate analysis (HR=0.64, 95% CI [0.51 - 0.81]), p < 0.001). Multivariate Cox analysis showed that the period of diagnosis remained significantly prognostic after adjustment on confounding factors (adjusted Hazard Ratio (aHR) 0.49, 95% CI [0.36-0.67], p < 0.001).

CONCLUSION

This increase of mOS over time in newly diagnosed GBM patients could be explained by better management of potentially associated non-neurological diseases, optimization of validated SOC, better management of treatments side effects, supportive care and participation in clinical trials.

OS07.1.A A threshold of mitotic activity and post-surgery residual volume are independant prognostic factors in astrocytoma IDH-mutant

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 of grade 2 versus 3 have not been updated since the WHO 2007 classification. There is no consensus on the method of evaluation of the mitotic activity or a cut-off of mitoses separating grade 2 and grade 3 tumors. The objectives were to evaluate the maximal mitotic activity on a series of resected astrocytoma IDH-mutant and assess its prognostic impact on survival.

Material and Methods

Maximal mitotic activity on consecutive high power fields corresponding to 3 mm2 was examined in 118 lower-grade astrocytoma IDH-mutant. The prognostic value for time-to-treatment (TTT) and overall survival (OS) of mitotic activity and other putative prognostic factors (including age, performance status, pre-surgical tumor volume, plurilobar involvement, post-surgical 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%) of tumors which had gone through observational follow-up after resection, the maximal mitotic activity, the post-surgical residual volume and the plurilobar involvement were independent prognostic factors of TTT (p &lt; 0.0001). A threshold of mitotic activity for grade 2 was fitted on TTT and OS prognosis. 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 &lt; 1 cm3 was associated with longer OS (113 months versus 88 months, p = 0.0021).

Conclusion

Mitotic activity and post-surgical residual volume can be combined to evaluate prognosis in resected astrocytoma IDH-mutant and could select the best candidates for observational follow-up.

KS02.4.A Olaparib in Recurrent IDH-mutant High-Grade Glioma (OLAGLI)

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 &gt; 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.

PL02.4.A Chromosome 1p19q codeletion frequency, but not survival, varies according to the IDH mutation subtypes: analysis of 1050 IDH-mutated diffuse gliomas

BACKGROUND

recurring hotspot mutations in isocitrate dehydrogenase (IDH) 1 enzymes, and to a lesser extent IDH2, are the main oncogenic alteration in most of lower-grade diffuse gliomas and a subset of grade 4 gliomas. Although most commonly represented by the IDH1R132H mutation, non-canonical IDH1/2-nonR132H mutations are present in about 10% of cases. As the neomorphic enzymatic activity can vary depending on the type of the hotspot mutation, a different biological behaviour may be inferred. Nevertheless, the prognostic significance of the different IDH1/2 mutations remains a matter of debate.

MATERIAL AND METHODS

we queried the OncoNeuroTek tumor bank (Pitié-Salpêtrière Hospital, Paris) to identify all registered cases of IDH-mutated diffuse gliomas. Most relevant clinical and molecular data were collected.

RESULTS

We identified 1050 IDH mutated diffuse gliomas (481 grade 2 [46%], 459 grade 3 [44%], and 110 grade 4 [10%]), of which 1007 (96%) were IDH1 mutated (934 IDH1R132H [89%] and 73 IDH-nonR132H [7%]) and 43 (4%) were IDH2 mutated (24 IDH2R172K [2%] and 19 IDH2-nonR172K [2%]). The chromosomes 1p/19q codeletion was more frequent in IDH2-mutated tumors (25/42 [60%] versus 350/918 [38%] in IDH1-mutated cases, p=0.005). Nevertheless, only IDH2R172K mutation was associated with the codeletion (18/24 [75%], versus 7/18 [39%] in IDH2-nonR172K-mutated tumors, p=0.02). IDH1-nonR132H tumors showed the lowest rate of 1p/19q codeletion (9/69 [13%], versus 341/849 [40%] in IDH1R132H-mutated cases, p&lt;0.001). At the time of observation, 536 patients were deceased (51%), with a median overall survival (OS) of 115 months (mo., 95% CI 108–125 mo.). Median follow up for censored patients was 77 mo. Codeleted patients had a significantly longer OS compared to non-codeleted ones (179 vs. 96 mo., p&lt;0.001). No significant differences in survival were seen when stratifying according to IDH mutation type (115 mo. for IDH1R132H vs. 136 mo. for IDH1-nonR132H vs. 112 mo. for IDH2R172K vs. 150 mo. for IDH2-nonR172K, p=0.8). No differences were seen when restricting the analysis to codeleted or not-codeleted patients only, respectively. In a multivariate analysis including the main prognostic factors (age, sex, preoperative performance status, tumor grade, surgical resection, midline location, 1p/19q codeletion, and p16 homozygous deletion), no survival difference was associated with any of the IDH mutation subtype.

CONCLUSION

although significantly different rates of 1p/19q codeletion were seen according to the four main IDH mutation subgroups, these groups does not associate with different survival profiles in our cohort.

OS05.2.A MGMT promoter status in IDH1/2 mutant anaplastic astrocytoma patients assessed by DNA methylation profiling and qMS-PCR: a report from the EORTC Brain Tumor Group

BACKGROUND

Temozolomide (TMZ) efficacy in high-grade glioma is related to O 6-methylguanine DNA methyltransferase promoter (MGMTp) methylation. We compared the prognostic and predictive effect of MGMTp between DNA methylation profiling (the MGMT-STP27 model) and quantitative methylation specific polymerase chain reaction (qMS-PCR) in isocitrate dehydrogenase 1 and 2 (IDH1/2) mutant (mt) anaplastic astrocytoma patients.

MATERIAL AND METHODS

The 2x2 factorial design phase III CATNON trial randomized 751 adult patients with newly diagnosed 1p/19q non-codeleted anaplastic glioma to 59.4 Gy radiotherapy (RT), RT with concurrent TMZ, RT with 12 cycles of adjuvant TMZ, or RT with concurrent and adjuvant TMZ. MGMTp methylation status was assessed with the MGMT-STP27 model using 850k EPIC data, and qMS-PCR. IDH1/2 mutation status was determined with a next-generation sequencing panel. Overall survival (OS) was measured from date of randomization.

RESULTS

We identified 444 IDH1/2mt anaplastic astrocytoma patients of which MGMT-STP27 data was available for 440 patients (99.1%), qMS-PCR data for 361 patients (81.3%), and both for 357 patients (80.4%). MGMTp was methylated in 365 patients (83.0%) for the MGMT-STP27 model, and 168 patients (46.5%) for qMS-PCR. The agreement between the MGMT-STP27 model and qMS-PCR is 59.9% with a Cohen’s Kappa score of 0.229. At database lock, 289 patients with MGMT-STP27 data were still alive and 236 patients with qMS-PCR data. The median OS of MGMTp methylated glioma patients was 9.1 yrs [95 % confidence interval (CI) 7.5-not reached] for the MGMT-STP27 model, and not reached [95 % CI 9.1-not reached] for the qMS-PCR data. For MGMTp unmethylated glioma patients, the median OS was 6.9 yrs [95% CI 6.2-not reached] for the MGMT-STP27 model, and 6.8 yrs [95% CI 6.2–9.7] for the qMS-PCR data. The hazard ratio (HR) for OS based on MGMTp methylation was 0.88 [95% CI 0.58–1.31] for the MGMT-STP27 data, and 0.72 [95% CI 0.50–1.03]) for the qMS-PCR data. The HR for OS after RT with any TMZ vs RT alone for the MGMT-STP27 model was 0.53 [95% CI 0.37–0.78] for MGMTp methylated, and 0.54 [95% CI 0.25–1.18] for MGMTp unmethylated glioma patients; and for the MS-PCR data was 0.34 [95% CI 0.19–0.61] for MGMTp methylated, and 0.53 [95% CI 0.33–0.85] for MGMTp unmethylated glioma patients.

CONCLUSION

MGMTp methylation, regardless of assay, was neither prognostic nor predictive for outcome to temozolomide in IDH1/2mt anaplastic astrocytoma patients.

Prognostic significance of genome-wide DNA methylation profiles within the randomised, phase 3, EORTC CATNON trial on non-1p/19q deleted anaplastic glioma

Background

Survival in patients with IDH1/2-mutant (mt) anaplastic astrocytomas is highly variable. We have used the prospective phase 3 CATNON trial to identify molecular factors related to outcome in IDH1/2mt anaplastic astrocytoma patients.

Methods

The CATNON trial randomized 751 adult patients with newly diagnosed 1p/19q non-codeleted anaplastic glioma to 59.4 Gy radiotherapy +/− concurrent and/or adjuvant temozolomide. The presence of necrosis and/or microvascular proliferation was scored at central pathology review. Infinium MethylationEPIC BeadChip arrays were used for genome-wide DNA methylation analysis and the determination of copy number variations (CNV). Two DNA methylation-based tumor classifiers were used for risk stratification. Next-generation sequencing (NGS) was performed using 1 of the 2 glioma-tailored NGS panels. The primary endpoint was overall survival measured from the date of randomization.

Results

Full analysis (genome-wide DNA methylation and NGS) was successfully performed on 654 tumors. Of these, 432 tumors were IDH1/2mt anaplastic astrocytomas. Both epigenetic classifiers identified poor prognosis patients that partially overlapped. A predictive prognostic Cox proportional hazard model identified that independent prognostic factors for IDH1/2mt anaplastic astrocytoma patients included; age, mini-mental state examination score, treatment with concurrent and/or adjuvant temozolomide, the epigenetic classifiers, PDGFRA amplification, CDKN2A/B homozygous deletion, PI3K mutations, and total CNV load. Independent recursive partitioning analysis highlights the importance of these factors for patient prognostication.

Conclusion

Both clinical and molecular factors identify IDH1/2mt anaplastic astrocytoma patients with worse outcome. These results will further refine the current WHO criteria for glioma classification.

miR-379 links glucocorticoid treatment with mitochondrial response in Duchenne muscular dystrophy

Duchenne Muscular Dystrophy (DMD) is a lethal muscle disorder, caused by mutations in the DMD gene and affects approximately 1:5000-6000 male births. In this report, we identified dysregulation of members of the Dlk1-Dio3 miRNA cluster in muscle biopsies of the GRMD dog model. Of these, we selected miR-379 for a detailed investigation because its expression is high in the muscle, and is known to be responsive to glucocorticoid, a class of anti-inflammatory drugs commonly used in DMD patients. Bioinformatics analysis predicts that miR-379 targets EIF4G2, a translational factor, which is involved in the control of mitochondrial metabolic maturation. We confirmed in myoblasts that EIF4G2 is a direct target of miR-379, and identified the DAPIT mitochondrial protein as a translational target of EIF4G2. Knocking down DAPIT in skeletal myotubes resulted in reduced ATP synthesis and myogenic differentiation. We also demonstrated that this pathway is GC-responsive since treating mice with dexamethasone resulted in reduced muscle expression of miR-379 and increased expression of EIF4G2 and DAPIT. Furthermore, miR-379 seric level, which is also elevated in the plasma of DMD patients in comparison with age-matched controls, is reduced by GC treatment. Thus, this newly identified pathway may link GC treatment to a mitochondrial response in DMD.

PL3.3 Second interim and first molecular analysis of the EORTC randomized phase III intergroup CATNON trial on concurrent and adjuvant temozolomide in anaplastic glioma without 1p/19q codeletion

BACKGROUND

The 1st interim analysis of the CATNON trial showed benefit from adjuvant (adj) temozolomide (TMZ) on overall survival (OS) but remained inconclusive about concurrent (conc) TMZ. A 2nd interim analysis was planned after 356 events.

MATERIAL AND METHODS

The 2x2 factorial design phase III CATNON trial randomized 751 adult patients with newly diagnosed non-codeleted anaplastic glioma to either 59.4 Gy radiotherapy (RT) alone; the same RT with concTMZ; the same RT and 12 cycles of adjTMZ or the same RT with both concTMZ and adjTMZ (doi: 10.1016/S0140-6736(17)31442-3). MGMT promoter methylation (MGMTmeth) status was re-assessed with the Infinium Methylation EPIC Beadchip using the MGMT_STP27 model. Isocitrate dehydrogenase 1 and 2 (IDH) mutation (mt) status was assessed with glioma targeted Agilent SureSelect baits sequence using an Illumina HiSeq2500 Rapid PE100.

RESULTS

With a median follow-up of 56 months and 356 events, the hazard ratio (HR) for OS adjusted for stratification factors after concTMZ was 0.968 (99.1% CI 0.73, 1.28). 5-year OS was 50.2% with and 52.7% without concTMZ (95% CI [44.4, 55.7] and [46.9, 58.1]). An IDHmt was found in 335 of 480 assessed cases (70%). Median OS was 19 mo (95% CI 16.3, 22.3) in IDHwt tumors and 116 mo (95% CI 82.0, 116.6) in IDHmt tumors. The interaction test based on IDH status was significant (p=0.016) in the univariate HR analysis for OS after concTMZ (IDHwt, n=145, events=120, HR = 1.27, 95% CI 0.89, 1.82, p=0.19; IDHmt, n=335, events=92, HR= 0.67, 95% CI 0.44, 1.03, p=0.06). IDHmt was predictive of benefit from adjTMZ (IDHmt HR: 0.41, 95% CI 0.27, 0.64; IDHwt: HR 1.05, 95% CI 0.73, 1.52; interaction test p = 0.001). In IDHmt patients that received adjTMZ, the HR for OS after concTMZ was 0.71 (95% CI 0.35, 1.42, p=0.32). MGMTmeth was found in 288 of 410 assessed cases (70%), interaction test for concTMZ (p = 0.092) and adjTMZ (p = 0.166) did not reach statistical significance.

CONCLUSION

In the entire study cohort, concTMZ did not increase OS. However, in IDHmt tumors a trend towards benefit of concTMZ is present. AdjTMZ increased OS in IDHmt but not in IDHwt tumors. Further analyses and follow-up will allow full assessment of efficacy in the molecular subgroups.

OS4.3 Feasibility and benefit of Molecular Profiling to Guide Enrollment of Patients with Recurrent Gliomas in Early Phase Trials

BACKGROUND

Participation of glioma patients in early phase clinical trials has recently shown to be safe, although clinical benefits reported in this population were marginal. We aimed to evaluate whether an enrichment strategy based on molecular profiling associates with improved outcome in gliomas patients participating in early phase trials.

MATERIAL AND METHODS

Records of patients enrolled in early phase trials of cytotoxic therapies, small molecule inhibitors or monoclonal antibodies from 2008 to 2017 were analyzed for clinicopathological characteristics, toxicity, response, median progression-free survival (PFS) and overall survival (OS). The primary objective was to evaluate the feasibility and benefit of using molecular profiling to guide enrollment.

RESULTS

Ninety-one patients were enrolled, of whom 47/91 (51.6%) were molecularly oriented. Molecular targets included IDH1/2 (n=15) and BRAF (11) mutations, FGFR1-3 fusions (n= 10) and mutations (n = 4), mismatch repair deficiency (8), and MDM2 amplification (1). Grade 3/4 adverse events were reported in 9/91 (9.9%) patients. In patients with IDH1/2-wild-type high-grade glioma (n=45), the overall response rate (24.0% [95% CI 11.5–43.4] vs 0.0% [95% CI 0.0–16.1], P=0.027) was significantly higher in molecularly-oriented vs non-molecularly-oriented patients. Updated outcome results, and clinical and molecular factors associated with response, PFS and OS in multivariate analyses will be presented at the conference.

CONCLUSION

Using molecular profiling to guide enrollment in early phase trials is feasible and offers potential benefit to gliomas patients. Further studies are warranted to identify the population most likely to benefit from this approach.

OS8.5 How to assess meningioma therapy activity: The CEVOREM independent central review experience

BACKGROUND

Meningioma therapy efficiency is used to being assessed by 6 months progression survival rate (PFS6), which remains the most consensual criterion. Nevertheless, different patterns of meningiomas intrinsic aggressiveness and growth rates directly impact the PFS6 leading to unreliability of drug effect assessment. Moreover, therapeutic response remains rare in meningiomas. These points lead to consider classical and updated RANO criteria as not fully adapted to meningiomas. Based on phase II CEVOREM trial experience, we aim to improve the assessment of drugs efficiency in meningiomas via the determination of growth rate before and under treatment.

MATERIAL AND METHODS

Twenty patients were included in Cevorem trial which tested the combination of octreotide and everolimus as previously described. MRI assessment was performed in the 3 to 6 preinclusion months, at inclusion then every 3 months. Progression was assessed by investigators according to RANO criteria. An independent central review was performed with 2 reviewers and 1 adjudicator: largest diameter, 2D maximal area as 3D volume were assessed by autosegmentation software (Brainlab). Results from central review were correlated to investigators assessment. 3D volume growth rate (3DVGR) was calculated using 2 different processes (one simple and one complex). Comparison of 3DVGR before vs. under treatment was performed. Meningioma growth under treatment was compared to theoretical meningioma growth based on preinclusion data using a model of meningioma growth.

RESULTS

PFS6 assessed via the independent central review was in accordance with PFS6 assessed by investigators following RANO criteria. Then, we analyzed 3DVGR before and during therapy. Standard deviation was higher using the complex 3DVGR calculation process. A decrease of more than 50% of the 3DVGR was observed in 30/36 tumors at 3 months with the both calculation modes and could be considered as a threshold of drugs activity. Median volume growth rate decreased from 88.3 or 17.2%/3 months before inclusion to -2.2 or à -0.6 %/3mo at 3 months depending of the calculation mode (p <0.0002). Nevertheless, in our study, decrease in 3DVGR was associated with a prolonged free progression period when 3DVGR decreased around 0 or negative. Comparison of theoretical meningioma growth curve based on preinclusion data with under treatment growth curve is ongoing. Some limits remain: 3DVGR calculation remains directly related to the volume assessment accuracy and 3DVGR can be very high particularly in case of very small initial tumor which cannot be mitigated by current mathematical models.

CONCLUSION

3DVGR measurement during versus before seems as a sensitive and reliable tool which provides valuable comparison in a phase 2 study to assess drugs activity in meningioma in complement to PFS6. 3DVGR assessment should be considered in future clinical trials.

OS9.7 Telomere length, TERTp mutation and ALT status in adult diffuse gliomas

BACKGROUND

The current classification of adult diffuse gliomas integrates two alternative telomere maintenance mechanisms: reactivation of telomerase activity by TERT promoter (TERTp) mutations or ATRX mutations associated with alternative length telomere (ALT). We investigated here the relation between these two mechanisms, telomere length, and outcome in a large series of diffuse gliomas.

MATERIAL AND METHODS

We performed C-circle assay (CCA) to determine ALT status, determined telomere length in tumor (RTLt) and leukocyte (RTLl) in a cohort of 354 adult diffuse gliomas, and sequenced ATRX gene. We calculated an age-adjusted telomere score considering tumor and leukocyte (blood) telomere length and corrected by age. This score was used in univariate and multivariate survival analyses to evaluate the potential impact of telomere length on the prognosis of gliomas. We used the TCGA LGG-GBM dataset to validate our findings in an independent cohort.

RESULTS

RTLl and RTLt were associated with ATRX mutation and ALT phenotype, and negatively associated with age and TERTp mutations. ATRX mutations (found in 52% (64/123) of samples) were mostly transitions (C>T or T>C), and were associated with ALT phenotype. None of 1p/19q co-deleted oligodendrogliomas harbored an ALT phenotype. No patients with TERTp mutations had ALT phenotype except for a very small subgroup of patients (3/87, 3.4%) suggesting that multiple ways of telomere maintenance, may co-exist in a single tumor, probably expressed in different clones. Telomere age-adjusted score was independently associated with better outcome (HR= 0.73 [95% CI 0.56–0.97], p-value 0.03 adjusted for age, TERTp mutation, IDH mutation, 1p/19q co-deletion and WHO grade). These results were validated using the LGG-GBM TCGA dataset.

CONCLUSION

We unravel the relation between RTLl and RTLt, TERTp mutation and ALT phenotype and describe a novel telomere age-adjusted score independently associated with better prognosis in adult diffuse gliomas.

P04.10 IDH-wildtype low grade gliomas: overall survival and prognostic indicators

BACKGROUND

IDH-wildtype WHO grade II diffuse gliomas represent a rare subgroup of low grade tumors characterized by poor prognosis. The clinical and molecular profile associated with these tumors has not been fully elucidated yet, and the ongoing uncertainties regarding their biological behavior hamper to establish a standard of treatment. The aim of this study is to define the median overall survival and the main prognostic factors associated with this rare tumor entity.

MATERIALS AND METHODS

We performed a retrospective research in our center for all patients diagnosed with diffuse WHO grade II and III gliomas from 1976 to 2018. WHO grade II and III gliomas were divided into three molecular subgroups according to the IDH1/2 mutation and the 1p/19q codeletion status (1: IDH-mutant, 1p/19q codeleted; 2: IDH-mutant, 1p/19q non codeleted; 3: IDH-wildtype). We analyzed the clinical and molecular characteristics of the three subgroups, and then the clinical, radiological, histological and molecular features of IDH-wildtype WHO grade II gliomas.

RESULTS

We identified 445 patients with diffuse WHO grade II gliomas, including 59 IDH1/2-wildtype tumors. IDH-wildtype grade II gliomas affected more frequently male (75% vs. 55%, p = 0.004) and older (mean age: 50.0 vs. 39.6 years, p<0.0001) patients, had frequent fronto-temporo-insular location (41%) and commonly underwent biopsy (53%) rather than resection. We found TERT promoter mutations (18/42, 43%), chromosome 7q gains (12/30, 40%), chromosome 10q losses (12/44, 27%), chromosome 9p losses (7/47, 15%), EGFR amplifications (5/51, 10%) and p16 deletions (4/50, 8%) but no P53 (0/16) mutations. Median overall survival was 46 months (vs. 98 for IDH-mutant non codeleted and 175 for IDH-mutant codeleted WHO grade II gliomas (p<0.0001); vs. 20 months for IDH-wildtype WHO grade III gliomas (p = 0.001)). Survival was not significantly influenced by age, preoperative KPS, tumor location, extent of resection or adjuvant treatment schemes. Chromosome 9p loss had a strong negative impact on overall survival (p=0.002).

CONCLUSION

The median overall survival associated with IDH-wildtype WHO grade II gliomas does not exceed 4 years from diagnosis. As some genetic alterations seem to have a strong prognostic impact, an exhaustive genetic assessment can be helpful in this rare tumor group for purposes of prognostic stratification and treatment decision.

PL1.2 Multiparametric assessment of factors influencing 2 HG accumulation in diffuse brain gliomas

BACKGROUND

2-hydroxyglutarate (2HG) can be detected non-invasively in IDH-mutant gliomas by in vivo magnetic resonance spectroscopy (MRS). We investigated factors affecting 2 HG accumulation and explored the prognostic value of 2 HG detection in IDH mutant gliomas and 2 HG variations during anti-cancer therapies.

MATERIAL AND METHODS

We prospectively scanned by MEGA-PRESS 70 glioma patients (24 before surgery and 46 IDH mutant operated glioma) and measured 2HG. CRLB cut-off was 50%. We followed up 9 IDH mutant patients during radiotherapy and chemotherapy.We analyzed radiological parameters (tumor and cystic/necrotic volumes, fractions of VOI filled with tumor, spectroscopic profile, “infiltrative” versus “expansive” morphology, contrast-enhancement) and genetic profile (IDH1, IDH2, 1p19q codeletion). 2HG concentrations in plasma, urine, and surgical obtained samples were measured by gas chromatography-mass spectrometry (GC-MS).

RESULTS

MEGA-PRESS sequence detected 2HG with a sensitivity of 95% in untreated patients, and of 69% in pre-treated patient. Positive predictive value was 100% in both groups. 2HG was lower in pre-treated IDH mutant gliomas (1.1 versus 2.3 mM, P=0.02) and decreased rapidly during radiotherapy and chemotherapy before any radiological change. 2HG detection was positively correlated with tumor volume (P=0.02), choline measurements (r=0.58 P<0.0001), cellular density (measured by restricted diffusivity, Pearson r -0.40 P=0.01), “expansive” presentation, mutated reads/total reads ratio by NGS and was inversely correlated with Myo-inositol (Pearson R -0.29 P=0.03) and cystic/necrotic areas (P=0.04). 2HG by MRS positively correlated with urine 2HG (r=0.80 P=0.003). 2 HG was higher in IDH2 mutant (4.7 versus 2.4 Mm, P=0.02) and lower in non R132H IDH1 mutant (1.12 mM P=0.004). Among IDH mutant glioma patients, 2 HG detection was associated with longer survival (HR 0.09; 95%CI 0.018–0.52).

CONCLUSION

Tumor volume, cellular density, previous radio- and chemotherapy and genetic features determine 2 HG detection in IDH mutant gliomas. 2 HG detection is associated with better outcome and can be reliably monitored during anti-cancer treatments.

P04.12 Characteristics of IDH-mutant gliomas with non-canonical IDH mutations

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<0.05). In both IDH1 R132H-mutant and non-canonical IDH-mutant gliomas the most frequent location was the frontal lobe. Yet, compared to IDH1R132H-mutant gliomas those with a non-canonical IDH mutation had more frequently an infratentorial location (5,5% vs 0% p<0,05) and were more frequently multicentric (4,9%, versus 0.9%, p<0.05). Compared to IDH1R132H-mutant gliomas, gliomas with a non-canonical IDH1 mutation were more frequently astrocytomas (65.7% vs 45%, p<0.05) while those with an IDH2 mutation were more frequently oligodendrogliomas (82% vs 55%, p<0.05). The median overall survival in IDH1 R132H-mutant and non-canonical IDH-mutant gliomas was similar (122 versus 120 months).

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.

Antineoplastic agents exacerbating Charcot Marie Tooth disease: red flags to avoid permanent disability

BACKGROUND

Charcot Marie Tooth (CMT) disease is the most common form of hereditary neuropathy. Due to the high prevalence of mild and undiagnosed forms, patients with CMT disease may be exposed to severe neurotoxicity following the administration of neurotoxic chemotherapies. The aim of this report is to alert oncologists to the potential to precipitate severe irreversible peripheral neuropathies when administering neurotoxic compounds to undiagnosed CMT patients.

MATERIAL AND METHODS

A retrospective research in the OncoNeuroTox database was performed (2010-2016), searching for patients with the diagnosis of chemotherapy-induced peripheral neuropathy (CIPN) and CMT disease. A comprehensive literature review for previously published cases was performed using the Pubmed and Cochrane databases (1972-2017).

RESULTS

Among 428 patients with CIPN, we identified eight patients with concomitant CMT disease. Seven patients out of the eight had no previous diagnosis of CMT disease, although accurate familial history disclosed mild signs of peripheral neuropathy in five cases. Patients themselves had minor stigmata of long-standing peripheral damage. Patients received chemotherapy regimens based on vinca alkaloids, taxanes or a combination of vinca alkaloids and platinum compounds. In two cases, cumulative doses were below or equal to the expected neurotoxic threshold. Following chemotherapy administration, patients developed severe length-dependent sensory-motor deficits. Despite early drug discontinuation, most patients remained severely disabled.

CONCLUSION

A brief checklist to disclose long-standing signs of peripheral neuropathy could be helpful to detect patients with undiagnosed hereditary neuropathies who could be at risk of developing severe irreversible neurotoxicity following the administration of neurotoxic agents.

Glioblastoma targeted therapy: updated approaches from recent biological insights

Glioblastoma (WHO grade IV astrocytoma) is the most frequent primary brain tumor in adults, representing a highly heterogeneous group of neoplasms that are among the most aggressive and challenging cancers to treat. An improved understanding of the molecular pathways that drive malignancy in glioblastoma has led to the development of various biomarkers and the evaluation of several agents specifically targeting tumor cells and the tumor microenvironment. A number of rational approaches are being investigated, including therapies targeting tumor growth factor receptors and downstream pathways, cell cycle and epigenetic regulation, angiogenesis and antitumor immune response. Moreover, recent identification and validation of prognostic and predictive biomarkers have allowed implementation of modern trial designs based on matching molecular features of tumors to targeted therapeutics. However, while occasional targeted therapy responses have been documented in patients, to date no targeted therapy has been formally validated as effective in clinical trials. The lack of knowledge about relevant molecular drivers in vivo combined with a lack of highly bioactive and brain penetrant-targeted therapies remain significant challenges. In this article, we review the most promising biological insights that have opened the way for the development of targeted therapies in glioblastoma, and examine recent data from clinical trials evaluating targeted therapies and immunotherapies. We discuss challenges and opportunities for the development of these agents in glioblastoma.

Adenovirus related lymphohistiocytic hemophagocytosis: Case report and literature review

INTRODUCTION

Adenoviral infection is a classic cause of lymphohistiocytic hemophagocytosis (LH) in bone marrow transplantation but is rare outside this setting.

CASE REPORT

A 31-year-old female, with a history of treated mesencephalic astrocytoma, was hospitalized for fever, pancytopenia, elevated liver enzymes, hyperferritinemia and hypertriglyceridemia. Adenovirus viral load in blood was 7.3×10(9) copies/mL. Bone marrow aspirate examination confirmed LH. The patient recovered without specific LH or adenovirus-directed treatment.

CONCLUSION

Adenovirus-related LH, common in bone marrow transplant recipients, should also be considered in patients with chemotherapy in solid tumors.

LRP1B deletion is associated with poor outcome for glioblastoma patients

INTRODUCTION

Deletion of the tumor suppressor gene LRP1B has been reported in glioblastoma, the most aggressive primary brain tumor in adults. Our objective was to analyze frequency and prognostic impact of LRP1B deletion and expression levels.

METHODS

We retrospectively included all the primary IDH1/2 wild-type GBM patients with available clinical follow-up, DNA and RNA from our database. Deletions were analyzed by SNP-array. LRP1B mRNA expression was analyzed by reverse transcription quantitative polymerase chain reaction.

RESULTS

178 patients were included with a median age of 62.36 years. LRP1B deletions were observed for 10.1% of patients (complete: 2.8%, partial: 7.3%). LRP1B deletions were associated with poor progression-free survival (PFS) (p=0.004) and overall survival (OS) (p=0.001). By multivariate analysis, LRP1B deletions remained significant for both PFS (p=0.003, hazard ratio (HR): 2.261) and OS (p=0.001, HR: 2.609). LRP1B was down expressed with a mean relative expression of 46% comparatively to normal tissue. No association between LRP1B mRNA and patient outcome was observed. No correlation was found between the deletions and the mRNA down-expression. These results were validated using GBM TCGA data.

CONCLUSION

LRP1B presents with frequent molecular alterations which impact patient outcome, highlighting the potential interest of this gene for glioblastoma patients.

TERT promoter mutations in gliomas, genetic associations and clinico-pathological correlations

BACKGROUND

The role of telomerase reverse transcriptase (TERT) in gliomagenesis has been recently further strengthened by the frequent occurrence of TERT promoter mutations (TERTp-mut) in gliomas and evidence that the TERT SNP genetic rs2736100 influences glioma risk. TERTp-mut creates a binding site for Ets/TCF transcription factors, whereas the common rs2853669 polymorphism disrupts another Ets/TCF site on TERT promoter.

METHODS

We sequenced for TERTp-mut in 807 glioma DNAs and in 235 blood DNAs and analysed TERT expression by RT-PCR in 151 samples. TERTp-mut status and TERTp polymorphism rs2853669 were correlated with histology, genomic profile, TERT mRNA expression, clinical outcome and rs2736100 genotype.

RESULTS

TERTp-mut identified in 60.8% of gliomas (491 out of 807) was globally associated with poorer outcome (Hazard ratio (HR)=1.50). We defined, based on TERTp-mut and IDH mutation status, four prognostic groups: (1) TERTp-mut and IDH-mut associated with 1p19q codeletion, overall survival (OS)>17 years; (2) TERTp-wt and IDH-mut, associated with TP53 mutation, OS=97.5 months; (3) TERTp-wt and IDH-wt, with no specific association, OS=31.6 months; (4) TERTp-mut and IDH-wt, associated with EGFR amplification, OS=15.4 months. TERTp-mut was associated with higher TERT mRNA expression, whereas the rs2853669 variant was associated with lower TERT mRNA expression. The mutation of CIC (a repressor of ETV1-5 belonging to the Ets/TCF family) was also associated with TERT mRNA upregulation.

CONCLUSIONS

In addition to IDH mutation status, defining the TERTp-mut status of glial tumours should afford enhanced prognostic stratification of patients with glioma. We also show that TERTp-mut, rs2853669 variant and CIC mutation influence Tert expression. This effect could be mediated by Ets/TCF transcription factors.

Registered Replication Report: Schooler and Engstler-Schooler (1990)

Trying to remember something now typically improves your ability to remember it later. However, after watching a video of a simulated bank robbery, participants who verbally described the robber were 25% worse at identifying the robber in a lineup than were participants who instead listed U.S. states and capitals-this has been termed the "verbal overshadowing" effect (Schooler & Engstler-Schooler, 1990). More recent studies suggested that this effect might be substantially smaller than first reported. Given uncertainty about the effect size, the influence of this finding in the memory literature, and its practical importance for police procedures, we conducted two collections of preregistered direct replications (RRR1 and RRR2) that differed only in the order of the description task and a filler task. In RRR1, when the description task immediately followed the robbery, participants who provided a description were 4% less likely to select the robber than were those in the control condition. In RRR2, when the description was delayed by 20 min, they were 16% less likely to select the robber. These findings reveal a robust verbal overshadowing effect that is strongly influenced by the relative timing of the tasks. The discussion considers further implications of these replications for our understanding of verbal overshadowing.

Ongoing and prolonged response in adult low-grade gliomas treated with radiotherapy

The aim of the present study was to evaluate the impact of first-line radiotherapy on low-grade gliomas (LGGs) growth kinetics. The mean tumor diameter (MTD) of 39 LGGs was retrospectively measured on serial magnetic resonance images before (n = 16) and after radiotherapy onset (n = 39). After radiotherapy, a decrease of the MTD was observed in 37 patients. Median duration of the MTD decrease was 1.9 years (range 0-8.1 years). According to RANO criteria, the rates of partial and minor responses were 15 and 28 % at the first evaluation after radiotherapy and 36 and 34 % at the time of maximal MTD decrease. The presence of a 1p19q codeletion and the absence of p53 expression were associated with longer durations of MTD decrease (5.3 vs 1 years, p = 0.02 and 2.4 vs 1.8 years, p = 0.05, respectively) while no association was observed between IDH1-R132H expression and duration of MTD decrease. In most patients, MTD decrease after radiotherapy occurred in two phases: an initial phase of rapid MTD decrease followed by a second phase of slower MTD decrease. Patients with a high rate of MTD decrease during the initial phase (>7 mm/year) had both a shorter duration of response (1.9 vs 5.3 years, p = 0.003) and a shorter overall survival (5.5 vs 11.6 years, p = 0.0004). LGGs commonly display a prolonged and ongoing volume decrease after radiotherapy. However, patients who respond rapidly should be carefully monitored because they are at a higher risk of rapid progression.