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.

Human pegivirus identified in severe myelitis and optic neuritis in immunocompromised patients: A pathogenic role for a forgotten virus?

The role of Human pegivirus (HPgV) in patients with encephalitis has been recently questioned. We present cases of 4 patients with similar clinical, biological, and radiological characteristics, including a past history of transplantation with long-term immunosuppression and a progressive course of severe and predominantly myelitis, associated in 3 cases with optic neuropathy causing blindness. Extensive workup was negative but analysis of the CSF by use of pan-microorganism DNA- and RNA-based shotgun metagenomics was positive for HPgV. This case series further supports the hypothesis of HPgV CNS infection and highlights the utility of metagenomic next-generation sequencing of CSF in immunocompromised patients.

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.

P11.09.B Chemotherapy is an efficient treatment in primary CNS MALT lymphoma

Background

Mucosae-associated lymphoid tissue (MALT) lymphomas are a rare and still poorly understood form of primary central nervous system lymphoma (PCNSL). The aim of this study was to better describe these tumors and their management, and to better appreciate their long-term prognosis after treatment.

Material and Methods

Adult immunocompetent patients with primary CNS MALT lymphoma (PCNSML) were retrospectively selected from the database on PCNSL of the Pitié-Salpêtrière Hospital. All cases had double-read for pathology.

Results

Eleven PCNSML representing 1.7% of the 662 PCNSL included in the database were selected, There were 9 women and two men, all immunocompetent. Their median age was 56 years (min 29; max 78). The median time from first symptoms to diagnosis was 13 months and the median KPS at diagnosis was 90. Location was dural in 8 cases, suggestive of meningioma in 7 cases and of subdural hematoma in 1 case, and parenchymal in 3 cases. The disease was unifocal/localized in 4 cases and multifocal/diffuse in 7 cases. In 3 cases, it was the second reading that allowed making the diagnosis. In first-line treatment, all patients received chemotherapy (CT): “systemic” CT, i.e usually used in systemic MALT lymphomas, in 7 cases (n=7) and “CNS” CT, i.e usually used in CNS lesions in 4 cases. CT was preceded by surgery in 4 cases. No patient received radiotherapy in first line. According to the IPCG (International PCNSL Collaborative Group) criteria, the overall response rate was 7/11 (64%). At latest news, 5 patients had a persistent contrast enhancement, stable without any treatment since a median of 57 months, raising the question of complete response despite persisting contrast enhancement. No patient developed neurotoxicity except for one of the 2 patients who subsequently received radiotherapy. The median follow-up was 109 months. The median progression-free survival was 78.0 months (95% CI [43.4;NA[) and the 10-year overall survival rate was 90% (95% CI [0.7;1[).

Conclusion

This series confirms the classical clinical and radiological presentation of PCNSML. Compared to the literature where the treatment was based on radiotherapy in almost two thirds of cases, the therapeutic approach presented here appears unconventional. This is the first 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 their therapeutic response.

The TeloDIAG: how telomeric parameters can help in glioma rapid diagnosis and liquid biopsy approaches

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.

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.

OS02.6.A The TeloDIAG: How telomeric parameters can help in glioma rapid diagnosis and liquid biopsies approaches

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

P14.76 Characteristics of anaplastic oligodendrogliomas short-term survivors: a POLA network study

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<0.001) and less frequently presented with isolated seizures (9% vs 33%, p=0.0017). They presented with tumors that more frequently involved multiple lobes (66% vs 47%, p=0.03), had a higher rate of nuclear atypia (80% vs 48%, p<0.001), a higher proliferative index (Ki67, 26% vs 18%, p<0.001), a higher level of p53 expression (10.8% vs 3.9% p<0.001), and had a higher rate of chromosomal abnormalities (91% vs 71% p=0.008). Compared to > 5 years survivors, short-term survivors less frequently underwent a surgical resection (64% vs 89% p<0.001) and their initial treatment more frequently consisted in temozolomide chemotherapy alone (41% vs 20% p=0.008).

CONCLUSION

AO short-term survivors are associated with distinct clinical, radiological, histological and molecular characteristics at diagnosis.

OS9.2 Radiomics analysis of lower-grade gliomas, a POLA Network study

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.

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.

Supratentorial low-grade gliomas in older patients

BACKGROUND

Low-grade gliomas (LGG) are thought to be very rare in elderly patients (>60 years) and have not been thoroughly studied.

METHODS

A series of 62 elderly (>or=60 years of age) LGG patients were identified in a department database collecting information on pathologically identified adult supratentorial LGG. The clinical, radiologic, pathologic, and therapeutic data of these patients were analyzed and compared to those of 704 younger LGG patients (<60 years).

RESULTS

Comparisons between older and younger groups showed that elderly patients more often presented with a clinical deficit (p < 0.0001), a lower Karnofsky performance status (p = 0.0002), a larger tumor on MRI (p = 0.03), and a lower rate of tumor resection (p < 0.0001). Chemotherapy was more often used as first line treatment (p = 0.001). Among the patients who died of progressive disease, 55% of the elderly patients had not received radiotherapy compared to 11% in the younger group (p < 0.0001). Survival was shorter in older patients (p < 0.0001), with a 5-year survival rate of 40%. An astrocytic phenotype (p = 0.0097), increasing age (p = 0.0049), and a tumor crossing the midline (p = 0.028) were negative prognostic factors in the older group.

CONCLUSION

We found that 8% of low-grade gliomas (LGG) occur in older patients (>or=60 years of age). The clinical-radiologic picture of LGG in the elderly population differs from younger patients. Although long-term survival occurs, the course is generally more severe because elderly patients accumulate negative prognostic factors and because they are probably undertreated.

alpha-Internexin expression identifies 1p19q codeleted gliomas

BACKGROUND

alpha-Internexin (INA) is a proneural gene encoding a neurofilament interacting protein that is upregulated in some gliomas, particularly oligodendrogliomas.

METHODS

INA expression was evaluated by immunohistochemistry in a series of 122 gliomas, and correlated to the 1p19q codeletion, a favorable prognostic marker of oligodendroglial tumors.

RESULTS

INA expression was strong (>10% positive cells) in 22 cases (22 oligodendroglial tumors and 0 astrocytic tumors), weak (<10% cells) in 14 cases (12 oligodendroglial tumors, 2 glioblastoma with an oligodendroglial component, and 0 astrocytic tumors), and negative in 86 cases (49 oligodendroglial tumors, 9 glioblastoma with an oligodendroglial component, and 28 astrocytic tumors). Among the 27 tumors exhibiting the 1p19q codeletion (all with an oligodendroglial phenotype), INA was detected in 96% (26/27, 18 strong, 8 weak) as compared to 11% (10/95, 4 strong, 6 weak) in the tumors without 1p19q codeletion (with an oligodendroglial or an astrocytic phenotype) (p < 0.001). In oligodendroglial tumors, INA expression specificity for 1p19q codeletion was 86%, sensitivity 96%, positive predictive value 76%, and negative predictive value was 98%. The prognostic impact of INA expression could be evaluated in grade III oligodendroglial tumors. Similar to 1p19q deletion, positive INA expression was correlated with better progression-free survival (52.6 vs 8.7 months [p = 0.001]) and overall survival (121.1 vs 31.4 months [p = 0.0001]).

CONCLUSION

alpha-Internexin (INA) expression appears to be a simple, reliable prognostic marker and a surrogate marker of 1p19q codeletion.

[Bilateral papilledema: prospective study of fifty patients]

In this prospective study, we report fifty consecutive cases of bilateral papilledema without neurosurgical or obvious ophthalmologic etiology, referred to our institution between January 2005 and March 2007. Lumbar puncture with opening CSF pressure measurement distinguished two groups of patients: Group 1 (n=39) with and Group 2 (n=11) without intracranial hypertension. In Group 1, 9/39 patients presented secondary intracranial hypertension mainly due to cerebral venous thrombosis. In 30 patients, after complete investigations, a diagnosis of idiopathic intracranial hypertension was made: as commonly reported, patients were predominantly overweight (96.7% with body mass index>25kg/m2) young (mean age=27.6 years) and women (96.7%). Eleven patients with intracranial hypertension had no headaches. In Group 2, the most common diagnosis was bilateral non-arteritic anterior ischemic optic neuropathy, but rare causes have been identified.

[Sudden bilateral hearing loss disclosing meningeal carcinomatosis]

We report the case of a patient presenting a sudden bilateral hearing loss. Four years before, a bladder carcinoma was resected and a chemotherapy was started. Gadolinium-enhanced magnetic resonance images revealed enhancement of both acoustic nerves. Cerebrospinal fluid analysis showed malignant cells consistent with the initial bladder cancer. Meningeal metastases from bladder carcinoma are extremely rare. Systemic chemotherapy and its low meningeal diffusion may enhance the incidence of this complication. Bilateral hearing loss is a rare initial manifestation of meningeal carcinomatosis.