bluuebunny/crossref_metadata_2025 huggingface dataset:
OS01.5.A Neuron-specific enolase (NSE) and S100 serum levels in patients with active brain metastases from HER2-positive breast cancer treated with trastuzumab-deruxtecan (T-DXd): A biomarker analysis from the TUXEDO-1 trial
Authors: Berghoff A S , Bartsch R , Furtner J , Marhold M , Bergen E S , Roider-Schur S , Starzer A M , Forstner H , Rottenmanner B , Dieckmann K , Bago-Horvath Z , Widhalm G , Ilhan-Mutlu A , Minichsdorfer C , Fuereder T , Singer C F , Weltermann A , Haslacher H , Szekeres T , Puhr R , Preusser M
Published: September 2022

Background

T-DXd is a novel antibody-drug conjugate with high activity in HER2-positive metastatic breast cancer. The prospective, single-arm, single-centre phase II TUXEDO-1 trial showed clinically relevant activity of T-DXd in HER2-positive BC pts with active BM with an intracranial response rate of 73.3%. This biomarker sub-study of TUXEDO-1 aimed to investigate changes in the extent of metastases-induced brain damage in patients with and without response to therapy by measuring the serum levels of two proteins constitutively expressed in the human brain and measurable upon brain damage in the blood serum: NSE and S100.

Material and Methods

We assessed serum NSE (sNSE) and serum S100 (sS100) levels in a total of 37 blood samples drawn at cycles 1, 4 and end of treatment (EOT) in all patients of the intent-to-treat population of the TUXEDO-1 trial using commercially available ELISA assays. Intracranial radiological response was centrally assessed by a board-certified neuro-radiologist using RANO criteria. sNSE and sS100 levels were compared between responders and non-responders using the Mann Whitney U test and a significance level of 0.05.

Results

At baseline, we detected no significant difference of sNSE or sS100 levels between T-DXd responders and non-responders, respectively. Baseline median sNSE level was 10.6 ng/ml (interquartile range (IQR) 8.6-12.2) in T-DXd responders as compared with median 12.5 ng/ml (IQR 12.2-12.9) in the non-responder group (n.s.). At cycle 4, corresponding numbers were 8.1 ng/ml in responding patients (IQR 7-11.2) and 12.7 ng/ml (IQR 12.2-12.9) in non-responders, respectively (p=0.009). No differences in sS100 levels were observed between the groups at any time point.

Conclusion

In patients showing intracranial objective response to T-Dxd, sNSE levels were significantly lower at cycle 4 as compared with non-responders, suggesting a reduction in metastases-induced brain damage as a direct treatment effect. sNSE may be a clinically useful biomarker for longitudinal assessment of brain metastasis burden.
OS01.6.A Through the Looking Glass: CSF Proteomics for Glioma Monitoring and Response Assessment
Authors: Riviere-Cazaux C , Burns T
Published: September 2022

Background

The development of novel glioma therapies necessitates rapid, longitudinal, and individualized feedback from each patient's tumor. Due in part to the relative inaccessibility of dynamic gliomas, little information is available regarding mechanisms of in situ therapeutic response and resistance which may be needed to iteratively develop candidate therapies and combinations thereof. To address this challenge, we are performing glioma biomarker discovery by serial cerebrospinal fluid (CSF) sampling from Ommaya reservoirs to determine how the CSF proteome can reveal early longitudinal intelligence regarding glioma status, biology, and therapeutic response.

Material and Methods

Global proteomic analysis of CSF was performed on the Somalogic platform -- an aptamer-based technology for highly sensitive and specific analyses of over 7,000 proteins. Discovery analysis comprised of the top-500 ranked proteins in CSF from seven patients with high-grade gliomas (HGG) versus non-glioma controls. The top-500 HGG proteins were then preliminarily filtered to include only proteins that met two additional criteria: 1) decrease with lower tumor burden as defined by tumor resection, and 2) increase with greater tumor burden as defined by recurrence in individual paired patient samples.

Results

Proteomic enrichment analysis revealed a conserved HGG CSF proteomic signature defined by 79 proteins, including ones known to be over-expressed in solid tumor malignancies, such as retinoblastoma binding protein 4, heat shock protein 90, and sorcin. When queried in an independent validation cohort, the HGG proteomic signature was consistently enriched across 13 gliomas diverse in primary versus recurrent status, subtype, and grade, when compared to control CSF samples. In two patients for whom CSF was available prior to and immediately after resections, proteins in the HGG signature decreased as indicated by a lower tumor burden. Interestingly, the glioma CSF proteomic signature was highly enriched for blood-associated proteins (as defined by two paired sets of CSF samples with low vs. high hemoglobin), despite these patients' samples containing little-to-no hemoglobin proteins.

Conclusion

Global CSF proteomics acquired from longitudinal neurosurgical access to unique gliomas has the promise to yield biomarkers which may be used to gain insights regarding glioma biology, tumor burden, and evolution throughout a patient's disease and treatment course.
OS02.6.A Lacosamide in monotherapy in brain tumour-related epilepsy (BTRE): results from an Italian multicentre retrospective study
Authors: Bruno F , Mo F , Meletti S , Belcastro V , Quadri S , Napolitano M , Bello L , Dainese F , Scarpelli M , Florindo I , Mascia A , Pauletto G , Pellerino A , Giovannini G , Polosa M , Sessa M , Conti Nibali M , Di Gennaro G , Gigli G , Cavallieri F , Pisanello A , Rudà R
Published: September 2022

Background

Lacosamide (LCM) is a third-generation anti-seizure medication (ASM) approved for focal onset epilepsy in patients aged ≥4 years. Previous studies have reported an efficacy of LCM as add-on treatment in brain tumour-related epilepsy (BTRE). To date, there are no studies in the literature focusing on lacosamide used in monotherapy to treat BTRE. In our retrospective study we investigated efficacy and tolerability of LCM in monotherapy in a multicentre national cohort of primary brain tumour patients.

Patients and Methods

Adult patients who were treated with LCM in monotherapy were collected from 12 Italian Centres (either mainly involved in neuro-oncology or in epileptology). Main inclusion criteria were diagnosis of primary brain tumour; at least two focal-onset seizures in the disease course; LCM used either as primary or secondary monotherapy after withdrawal of previous ASMs. For each patient, we evaluated seizure freedom at 3 and 6 months (primary endpoints), side effects and drop-out rate (secondary endpoints).

Results

We collected 132 patients. The majority of patients had a diagnosis of diffuse gliomas, being those with lower-grade glioma 66 (50.0%) and those with glioblastoma 33 (25.0%). Overall, LCM led to seizure-freedom in 64.4% of patients at 3 months and 55% at 6 months. Patients who used two or more ASMs before LCM had a worse seizure control than patients in monotherapy with LCM as first choice.In 14 patients, we observed seizure control despite tumour progression on magnetic resonance (MRI). Multivariate analysis showed that gross-total resection at diagnosis and use of steroids were significantly associated with higher seizure freedom rate at 6 months. Side effects were mainly mild (grade 1-2 according to the CTCAE classification), and the drop-out rate was low (1.5%). The main side effects were dizziness and somnolence.

Conclusion

This is the first study on the role of LCM in monotherapy in BTRE. The study has shown a good efficacy and tolerability of LCM with more than a half of patients becoming seizure-free at 6 months and with a very low rate of drop-out. Further studies are needed to confirm these preliminary data in a prospective manner, adding quality of life and neurocognitive functions as endpoints.
OS03.4.A In vivo dynamics and anti-tumor effects of EpCAM-directed CAR T-cells against brain metastases from lung cancer
Authors: Xu T , Karschnia P , Cadilha B , Dede S , Lorenz M , Seewaldt N , Nikolaishvili E , Müller K , Blobner J , Teske N , Langer S , Obeck H , Lorenzini T , Mulazzani M , Zhang W , Ishikawa-Ankerhold H , Buchholz V R , Subklewe M , Thon N , Straube A , Tonn J , Kobold S , von Baumgarten L
Published: September 2022

Background

Lung cancer patients are at a particularly high risk for brain metastases, and a considerable number of affected patients succumb due to their intracranial disease. Chimeric Antigen Receptor (CAR) T-cells emerged as a powerful class of cell-based immunotherapy for hematological malignancies. However, it remains unclear whether CAR T-cells also represent a safe and effective therapeutic option for brain metastases.

Material and Methods

A fully syngeneic orthotopic cerebral metastasis model in mice was established by combining a chronic cranial window with repetitive intracerebral two-photon laser scanning microscopy. This approach enabled the in vivo characterization of red fluorescent CAR T-cells and tumor cells on a single-cell level over weeks. Intraparenchymal injection of Lewis lung carcinoma cells (expressing the tumor cell-antigen EpCAM) was performed, and CAR T-cells directed against EpCAM (EpCAMCAR T-cells) were injected into the adjacent brain parenchyma after solid brain tumors have formed.

Results

All mice had visible tumor take four days after the intracranial tumor cell injection, and rapid growth of solitary lesions was seen in the following days. No toxicities mediated by intracranially injected EpCAMCAR T-cells were encountered. In mice treated with EpCAMCAR T-cells, we initially observed substantial CAR T-cell accumulation within the tumor compared to controls (median number: 1700 versus 939 cells/mm2; p = 0.007). This was paralleled by lower velocities of EpCAMCAR T-cells, characterizing T-cell receptor (TCR)-mediated antitumor cytotoxicity due to long-lasting contacts between effector immune cells and tumor cells. Consequently, treatment with EpCAMCAR T-cells resulted in reduced tumorous growth as determined per in vivo microscopy (median tumor area on day 10: 1.8 versus 10.8 mm2; p = 0.001) and immunohistochemistry of excised brains (median tumor volume on day 10: 3.6 versus 33.2 mm3; p = 0.001). However, the number of EpCAM-directed CAR T-cells within the tumor markedly decreased during the observation period, pointing towards insufficient persistence of EpCAM-directed CAR T-cells. In line with these findings, survival was prolonged in mice receiving EpCAMCAR T-cells but long-lasting remission was rare (median survival: 15 versus 13 days; p = 0.012).

Conclusion

Our findings indicate that CAR T-cells injected into the cerebral parenchyma may induce relevant anti-tumor effects in brain metastases from lung cancer. Due to the translational nature of our study, prospective clinical cohorts appear warranted. Strategies improving the intratumoral persistence of CAR T-cells in brain metastases may be utilized to further boost the success of such promising therapy.
OS03.7.A Clinical characteristics, treatment and long-term outcome of patients with brain metastases from thyroid cancer - an analysis of the Vienna Brain Metastasis Registry
Authors: Wolff L , Steindl A , Dieckmann K , Gatterbauer B , Widhalm G , Berghoff A , Preusser M , Raderer M , Kiesewetter B
Published: September 2022

Background

The incidence of brain metastases (BM) in patients with thyroid cancer (TC) depends on the histological subtype. About 1% of patients with differentiated (DTC), 3% with medullary (MTC) and up to 10% with anaplastic thyroid cancer (ATC) develop BM. The diagnosis of BM drastically worsens the prognosis of TC. Given the rare incidence, little is known about the presentation and outcome of this cohort.

Material and Methods

Patients with a histologically verified diagnosis of TC and BM were identified from the Vienna Brain Metastasis Registry, a comprehensive database managed by the Division of Oncology, Medical University of Vienna, including patients with cerebral metastasis since 1990. Data were obtained from medical records comprising clinicopathological features, treatment, BM-specific characteristics and outcome.

Results

20/6074 patients included in the registry had a diagnosis of TC and radiologically verified BM. 13/20 (65%) were female and the median age at diagnosis of TC and manifestation of BM was 56 years (range 21-75) and 68 years (range 45-75), respectively. In terms of histology, 18/20 (90%) had DTC, one MTC and one ATC. Interestingly, 10/18 DTC presented with follicular histology which underlines the more aggressive course of this rare subtype. 6/20 (30%) had BM at primary diagnosis (DTC n=5, ATC n=1), while the remaining developed BM during follow-up. The median time to diagnosis of BM was 2.6 years for DTC (range 0-42), 22 years in the MTC patient and 2 months for ATC. Regarding BM-specific characteristics, all but one patient had symptoms due to BM (neurological deficits n=11, increased intracranial pressure n=5, seizures n=3). Most patients (13/20) had a singular BM, commonly located in the left hemisphere (8/13), and only one had more than three BMs. Upfront treatment for BM was local therapy (resection n=9, stereotactic radiosurgery n=7, whole brain radiotherapy n=3); one patient received supportive care only. The median overall survival (mOS) from diagnosis of TC was 6 years for DTC (range 2.5 months-42 years), 33 years for the MTC and 9 months for the ATC. The mOS from diagnosis of BM was 14 months for DTC (1.8 months-16 years), 22 years for the MTC and 3 months for the ATC.

Conclusion

Few patients with TC develop BM, which present commonly as single lesion. While in general BM constitute a poor prognostic factor, individual patients experience long-term survival following local therapy. More information about the optimal management of BM in TC is needed to enable guideline recommendations.
OS05.5.A Glioblastoma-instructed microglia transit to heterogeneous phenotypic states with dendritic cell-like features in patient tumors and patient-derived orthotopic xenografts
Authors: Yabo Y A , Pires-Afonso Y , Moreno-Sanchez P M , Oudin A , Kaoma T , Nazarov P V , Skupin A , Niclou S P , Michelucci A , Golebiewska A
Published: September 2022

Background

A major contributing factor to Glioblastoma (GBM) development and progression is its ability to evade the immune system by creating an immune-suppressive tumor microenvironment (TME). GBM-associated myeloid cells, including resident microglia, macrophages and other peripheral immune cells are generally geared towards tumor-supportive roles. It is however unclear whether such recruited myeloid cells are phenotypically and functionally identical. Here, we aim to understand the heterogeneity of the GBM TME, using an unbiased, marker-free approach to systematically characterize cell type identities at the molecular and functional levels.

Material and Methods

We applied single-cell RNA-sequencing, multicolor flow cytometry, immunohistochemical analyses and functional studies to examine the heterogeneous TME instructed by GBM cells. GBM patient-derived orthotopic xenografts (PDOXs) representing different tumor phenotypes were compared to glioma mouse GL261 model and patient tumors.

Results

We show that PDOX models recapitulate major components of the TME found in human GBM. Human GBM cells reciprocally interact with mouse cells to create a GBM-specific TME. The most prominent transcriptomic adaptations are found in tumor-associated macrophages (TAMs), which are largely of microglial origin. We reveal inter-patient heterogeneity of TAMs and identify key signatures of distinct phenotypic states within the microglia-derived TAMs across distinct GBM landscapes. GBM-educated microglia adapt expression of genes involved in immunosuppression, migration, phagocytosis and antigen presentation, indicating functional cross-talk with GBM cells. We identify novel phenotypic states with astrocytic and endothelial-like features. Identified gene signatures and phenotypic states are confirmed in GBM patient tumor tissue. Finally we show that temozolomide treatment leads to transcriptomic adaptation of not only the GBM tumor cells but also adjacent TME components.

Conclusion

Our data provide insights into the phenotypic adaptation of the heterogeneous TME instructed by GBM tumor. We confirm a crucial role of microglia in supporting the immunosuppressive TME and show that PDOXs allow to monitor the highly plastic GBM ecosystem and its phenotypic adaptations upon treatment. This work further confirms the clinical relevance of PDOX avatars for testing novel therapeutics including modalities designed to target the myeloid compartment.
OS07.1.A A threshold of mitotic activity and post-surgery residual volume are independant prognostic factors in astrocytoma IDH-mutant
Authors: Tran S , Thomas A , Touat M , Karachi C , Lozano F , Mokhtari K , Dehais C , Feuvret L , Carpentier C , Giry M , Doukani H , Lerond J , Marie Y , Sanson M , Idbaih A , Carpentier A , Hoang-Xuan K , Capelle L , Bielle F
Published: September 2022

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 < 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 < 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.
OS07.5.A Report from the pooled analysis of the randomized trials NORDIC, NOA-8 and CE.6 on elderly patients with glioblastoma
Authors: Gorlia T , Oppong F , O′Callaghan C , Wick W , Laperriere N , Weller M , Perry J , Reifenberger G , Tavelin B , Malmström A E
Published: September 2022

Background

The majority of patients diagnosed with glioblastoma are over 60 years old. Three randomized trials addressed the roles of radiotherapy (RT) and temozolomide (TMZ) for these patients. Two, the NORDIC and NOA-08 (N&N) compared RT versus TMZ head-to-head, the third, CE.6, randomized between hypofractionated RT and the combination of RT+TMZ. All showed significant benefit for the TMZ arms, especially for patients with MGMT promoter methylated tumors. An ongoing pooled analysis of these three trials focuses on identifying significant baseline prognostic factors and assess their value for predicting outcome in relation to treatment. The aim is improved selection of elderly patients with glioblastoma for their optimal treament; RT alone, TMZ with or without concomitant RT or palliative care.

Methods

The data of two phase 3 studies (N&N) were pooled to build a large dataset and findings are compared to CE.6 trial data. A re-assessment of the clinically most relevant MGMT cut-off is performed. The prognostic value of baseline clinical factors and quality of life scores, determined by the EORTC QLQ-30 and BN-20 questionnaires, are investigated. Data is also analysed to account for a possible impact of sex.

Results

The N&N dataset includes 715 and the comparative dataset (CE.6) 562 patients. Median age for N&N is 71 years and 73 for CE.6. In N&N and CE.6 respectively, 66.2% versus 70.5% underwent resection and 50.9% and 75.3% were on steroids at the time of study inclusion. In N&N, 401 patients received RT alone and 281 in CE.6, while 314 were randomized to TMZ alone in N&N and 281 to concomitant RT and TMZ in CE.6. For N&N MGMT promoter methylation status was successfully determined for 412 (57.6%) and 354 (63.0%) for CE.6. In a first report, patients with the combination of the comorbidities hypertension, diabetes and/or cerebrovascular insult had poorer prognosis when treated with TMZ.

Conclusion

An ongoing pooled analysis of the trials NORDIC, NOA-08 and CE.6 is expected to identify factors that will improve personalized medicine for elderly patients with glioblastoma. Reanalyzed MGMT promoter methylation data and the role of baseline quality of life for outcome will be reported.
OS07.9.A Gliocova: Impact of surgeon and centre volume on 30-day mortality, readmission and risk of complication after first surgical intervention in brain tumour patients in England diagnosed between 2013-2018
Authors: Mauricaite R , Williams M
Published: September 2022

Background

The Gliocova dataset uses linked English national cancer data on all 51,775 adult primary brain tumour patients diagnosed between 2013-2018. Here we are investigating the effect of surgeon and centre volume on post-surgical outcomes such as 30-day mortality, readmission and risk of complication.

Material and Methods

We selected patients from our dataset that have undergone surgical debulking or biopsy for the first time. We calculated surgeon and centre volume per 6 year period. To exclude non-tumour surgeons who might do occasional tumour cases as an emergency, we removed those that performed less than 12 operations over the 6 year period and to remove newly qualified/ near retirement surgeons we removed those that did not perform at least 1 operation within the 6 first months of 2013 and last 6 months of 2018. We developed univariate regression models to link surgeon and centre volume with 30-day mortality, readmission and risk of complication and are currently working on multivariate models including other predictors such as age, sex, Elixhauer comorbidity index, deprivation status, type of intervention (biopsy vs surgical debulking), and tumour type (i.e., Glioblastoma versus other types of brain tumours).

Results

We identified 29,258 patients (out of 51,775) that have undergone a surgical intervention (28,173 surgical debulking; and 1,207 biopsy). In-hospital mortality was 0.99% (N = 289), 30-day mortality was 2.3% (N = 677) and 30-day readmission was 12.7% (N = 3,725). No surgeons performed less than 1 operation during the first 6 months of 2013 or last 6 months of 2018. In univariate analyses, centre volume predicted the risk of 30-day mortality (p-value<0.01) and risk of complication (p-value<0.001), whereas surgeon volume only significantly predicted risk of complication (p-value<0.001). Neither surgeon volume nor centre volume were statistically significant predictors of 30-day readmission in univariate analysis.

Conclusion

As most surgeon and centre volume studies in brain tumour patients come from the United States, our study is one of a few in Europe to investigate this in a large adult brain tumour population. In our future work we will refine the model to account for patient factors, and assess the cost of complications and variation of these across centres, tumour types and other patient and hospital level characteristics. More information about the Gliocova project can be accessed here: https://blogs.imperial.ac.uk/gliocova/about-gliocova/. GlioCova is supported by the Imperial/NIHR BRC, and the members of the GlioCova EAG. This work uses data provided by patients and collected by the NHS as part of their care and support
OS08.2.A Three layers of neuronal-like mechanisms driving brain tumor invasion
Authors: Venkataramani V , Wick W , Kuner T , Winkler F
Published: September 2022

Background

Glioblastoma are characterized by their infiltration into the whole brain. Membrane protrusions of glioma cells called tumor microtubes are subcellular structures contributing to glioma cell invasion. They are the anatomical building block to build a functional and therapy-resistant tumor cell network interconnected by tumor microtubes (TMs) that characterizes a glioblastoma cell subpopulation, while other subpopulations appear unconnected to other glioma cells. The biological role of glioblastoma cells lacking connections with each other remains unclear. Furthermore, how neurogliomal synapses influence this subpopulation is unclear.

Material and Methods

Time-lapse in vivo two-photon microscopy and single-cell RNA-sequencing are combined to characterize functional different subpopulations of glioblastoma cells. Intravital, augmented microscopy, three-dimensional calcium imaging, electrophysiology and volume electron microscopy are used to investigate the role of neuronal invasion mechanisms and the role of neurogliomal synapses for tumor microtube generation and dynamics.

Results

In-vivo imaging revealed that glioblastoma cells lacking connections to other tumor cells and astrocytes were the main subpopulation driving glioblastoma invasion invasion. These glioblastoma cells were characterised with single-cell RNA-sequencing. This revealed that this subpopulation is enriched for neuronal, neural progenitor-like, and non-mesenchymal-like cell states as previously described. Sparse regions enriched with such tumor-cell and astrocyte-unconnected, invasive glioblastoma cells evolve over time into regions with tumor-cell and astrocyte-connected, glioblastoma cell networks reflected by molecular cell state changes that are reflected in cell state changes in different regions of human glioblastoma. In addition, mechanisms of glioblastoma cell invasion resembled neuronal and neural progenitor patterns during brain development. Lastly, neuronal activity stimulated neurogliomal synapses and subsequently increased glioblastoma cell invasivieness by stimulating generation of new tumor microtubes and enhanced tumor microtube dynamics.

Conclusion

This study uncovers three novel layers of neuronal features driving glioblastoma cell invasion. We are able to connect molecular, cellular heterogeneity and functional glioblastoma cell states interlinking heterogeneity and dissemination of glioblastoma, two important hallmarks of this disease. Lastly, this study delineates a potential roadmap to clinical translation with the multidimensional characterisation of human glioblastoma.
OS08.3.A Distinct systemic and tumor microenvironment immune landscapes discriminate across sellar tumor types and controls through a methylation-based deconvolution method
Authors: Herrgott G , Asmaro K , Thomas B , Nelson K , Cazacu S , Hasselbach L , Transou A , deCarvalho A , Mukherjee A , Robin A , Lee I , Kalkanis S , Rock J , Rock J , Noushmehr H , Castro A
Published: September 2022

Background

Systemic (Sys) and tumor microenvironment (TME) immune milieus play a pivotal role in tumor development, outcome and immunotherapy response predictions across a variety of central nervous system tumors. Genome-wide methylation profiling can reliably discriminate and estimate immune cell proportions present in the blood and within the tumor and has not been reported across sellar tumor types (STT).

Material and Methods

We estimated cell composition in liquid biopsy (LB, serum/plasma) and tissue specimens from 42 STT collections (i.e., pituitary neuroendocrine tumors [PitNETs; n=37] and craniopharyngiomas [CP; n=5]), and 26 nontumor controls (LB: 11; Tissue: 15) using MethylCIBERSORT, a methylation-based deconvolution algorithm and established immune cell signatures as reference. LB methylation was profiled with EPIC array. Correlations between estimated cell proportions across sample sources were explored (Spearman). Immune cell proportion hierarchical k-means clustering was performed across tissue and LB specimens. Similarly, mean comparisons between and across sample types and subgroups of interest were performed [Non-parametric Kruskal-Wallis, Wilcoxon rank-sum tests; p<0.05].

Results

We identified three immune-clusters across tissue specimens which distinguished controls (k3-cluster) from sellar tumor specimens (k1- and k2- clusters), primarily attributable to differential B-cell and monocyte proportions. Interestingly, a subset of PitNET and CP, belonging to the k2-cluster, presented a distinct immune profile compared to their K1-sellar tumor counterparts. Analysis of plasma-derived immune clusters revealed that PitNETs were distributed across four distinct immune patterns and CP clustered together with controls and a PitNET subset. One of the PitNET clusters was enriched with patients that died during follow-up and presented an enrichment of CD4-(including the regulatory subtype), CD8 and CD56-T and depletion of natural killer cells. Differences across serum- and tissue-derived clusters were present but less prominent than their plasma counterparts. No correlation between immune cell proportions across other clinicopathological features within each tumor type (sex, age, histotypes, invasion etc) was observed.

Conclusion

Our results suggest that PitNETs are characterized by differential TME and systemic immune subtypes which also distinguish these tumors from CP and controls. Additionally, distinct systemic immune composition between tissue and LB sources, more readily observed in plasma, suggest that the systemic response to the presence of the tumor is distinct from the immune response noted in the TME. Tumor immune subtyping may allow the stratification of STT according to immunotherapy response vulnerabilities.
OS08.4.A Analysis of melanoma brain metastasis immune microenvironment through multiplex gene expression profiling
Authors: Ricci A A , Collemi G , Orlando G , Tampieri C , Senetta R , Pellerino A , Bruno F , Melcarne A , Garbossa D , Rudà R , Soffietti R , Ribero S , Quaglino P , Cassoni P , Bertero L
Published: September 2022

Background

Novel immunotherapies based on targeting of specific immune checkpoints enabled a significant improvement of melanoma outcome, but melanoma brain metastases (BM) remain an unmet oncological need with an overall 2-year survival rate lower than 10%. Tumour immune microenvironment has been demonstrated to play a key role in BM establishment and development, but data regarding the specific milieu of melanoma BM is limited.

Material and Methods

Gene expression profiles of 55 samples of primary melanoma and BM were evaluated using the nCounter PanCancer IO 360 Panel (NanoString Technologies) targeting 770 mRNA involved in tumor immune microenvironment modulation. The case series consisted of 10 primary melanomas and their 10 matched BM, 25 unmatched BM, and 10 locally advanced control melanomas without evidence of BM after >5 year follow up.

Results

Among BM samples, most patients (25/45) were males and median age at BM diagnosis was 61,2 years with a median time to BM development of 2,1 years. Median OS from BM diagnosis was 1,3 years. Several genes resulted significantly downregulated in BM compared to primary melanomas, including SERPINB5 (p<0.001), ARG1 (p=0.0067), S100A8 (p<0.001), S100A9 (p<0.001), S100A12 (p=0.0037), IL1RN (p=0.0012), CCL21 (p=0.0012), CCL22 (p=0.0012) and CCL13 (p=0.037) and SELE (p=0.026); conversely, C7 was upregulated (p<0.001). Downregulated signatures in BM involved those associated with multiple immune cell populations, including neutrophils, dendritic cells, mast cells and Treg, as well as inflammatory chemokines, the CTLA4 immune checkpoint and ARG1 enzyme function; conversely, MAGEs-related signature was upregulated. Comparison between primary melanomas which developed BM and those which did not showed a significant overexpression of RRM2 (p=0.0247) and TNFRSF1A (p=0.032) genes in the latter group and an upregulation of the PD-1 pathway. Analysis according to tumour mutational status showed an upregulation of signatures associated with inflammatory chemokines, dendritic and myeloid cells and neutrophils. No differences were observed according to time to BM development and survival from BM diagnosis.

Conclusion

Our findings show that melanoma BM harbor distinct immunosuppressive mechanisms compared to primary tumors: this data elicits the importance of investigating the heterogeneity of BM microenvironment. Genes and pathways selectively overexpressed or downregulated in melanoma BM should be validated to be possibly considered as novel therapeutic targets.
OS08.5.A Adenovirus-mediated delivery of the MHC-II Transactivator CIITA gene induces tumor cell killing in immunocompetent glioblastoma organoids
Authors: Salvato I , Klein E , Forlani G , Poli A , Oudin A , Baus V , Golebiewska A , Accolla R , Niclou S P , Marchini A
Published: September 2022

Background

Although immunotherapies represent an encouraging approach against cancer, to date none translated to the clinical benefit in Glioblastoma (GBM). One aspect contributing to this failure is the highly immunosuppressive GBM microenvironment. Our approach to overcome immunosuppression is to increase anti-tumor immune responses via adenovirus (AdV)-mediated delivery of the MHC-II Transactivator (CIITA) gene. CIITA-induced MHC-II expression is anticipated to convert GBM cells into surrogate antigen presenting cells able to prime T helper cells, therefore promoting CD4+ and CD8+ mediated immunity.

Material and Methods

We generated AdVs containing wild type CIITA (Ad-CIITA) using a replication-defective serotype5 adenoviral backbone. AdVs containing a mutated, non-functional version of CIITA (Ad-CIITA mutant) and an empty CMV promoter (Ad-null) were used as controls. AdV-mediated MHC-II expression was monitored at mRNA, protein and cell surface level. For the functional assessment of anti-tumor immune responses, we developed an advanced human GBM organoid model system consisting of tumor organoids co-cultured with either human peripheral blood mononuclear cells (PBMCs) or isolated CD3+ T cells. T cell mediated tumor cell killing was monitored over time via live cell imaging and flow cytometry.

Results

We successfully constructed and produced a CIITA-armed AdV that induces MHC-II expression in infected GBM cells, indicating the efficient expression of transcriptionally active CIITA for at least six days post infection. In immunocompetent human GBM organoids, Ad-CIITA infection of tumor cells led to prominent organoid disruption and tumor cell death, an effect that was not observed in the absence of PBMCs or CD3+ T cells. Tumor organoids infected with Ad-CIITA mutant remained intact, demonstrating the implication of cell surface MHC-II molecules in the observed phenotype.

Conclusion

Our results demonstrate that AdV-mediated delivery of CIITA is a promising strategy to increase T cell mediated immunity against glioblastoma.
OS08.7.A Lomustine and the immunocytokine L19TNF are a promising treatment combination for recurrent glioblastoma
Authors: Look T , Puca E , Stucchi R , Luca R , Roth P , Neri D , Weller M , Hemmerle T , Weiss T
Published: September 2022

Background

Treatment options for recurrent glioblastoma are limited and with the possible exception of regorafenib, no agent has demonstrated superior activity to lomustine. Therefore, there is an urgent need for more effective treatment strategies for recurrent glioblastoma. Here, we investigated different treatment combinations based on the tumor-stroma targeting antibody-cytokine fusion protein L19TNF in preclinical glioma models and translated the most effective treatment combination to patients with recurrent glioblastoma.

Material and Methods

Orthotopic immunocompetent mouse glioma models were used to study the anti-glioma activity of L19TNF in combination with anti-PD1, bevacizumab or lomustine. Tumor growth was monitored by MRI. Flow cytometry and microscopy were used to characterize tumor-infiltrating-immune cells. MHC immunoaffinity purification and mass spectrometry were used to characterize the MHC immunopeptidome. Genetic mouse models were used to study immune-dependent effects. Subsequently, we translated the most efficient treatment combination to patients with recurrent glioblastoma within a phase I/II clinical trial (NCT04573192).

Results

The combination of L19TNF and lomustine demonstrated strong synergistic anti-tumor activity in two immunocompetent orthotopic glioma models and cured a majority of tumor-bearing mice. In contrast, combinations with anti-PD-1 or bevacizumab had only limited anti-glioma activity. Furthermore, compared to the monotherapies, the combination of L19TNF and lomustine led to the strongest increase in tumor-infiltrating lymphoid cells as demonstrated by flow cytometry and microsopy and to the highest number of peptides presented in the context of MHC-I. The treatment effect was abrograted in different genetic immunodeficient mouse models. The treatment combination of L19TNF and lomustine was well tolerated in the first patients treated within a phase I/II clinical trial and we observed partial tumor responses also in patients with an unmethylated MGMT promoter.

Conclusion

The combination of L19TNF and lomustine demonstrated promising anti-glioma activity and patients are currently recruited within a phase I/II clinical trial for patients with recurrent glioblastoma.
OS08.8.A Integrin-specific CAR T cells for the treatment of glioblastoma
Authors: Villars D , Hänsch L , Silginer M , Weiss T , Weller M , Roth P
Published: September 2022

Background

Current standard of care for glioblastoma patients has limited therapeutic efficacy and novel innovative treatment strategies are urgently needed. One such strategy is chimeric antigen receptor (CAR) T cell therapy that has shown great success in hematological malignancies. αv integrins are overexpressed in several neoplasms and have already been used as therapeutic targets for small molecule inhibitors and antibodies, which did not cause major toxicities. Herein, we propose αv integrins as an ideal target for CAR T cell therapy in glioblastoma.

Material and Methods

CAR T cells targeting specific heterodimers (αvβ3, αvβ5 or αvβ8) were generated by transducing primary human T cells from healthy donors with a lentiviral vector expressing a second-generation CAR. Activity and specificity of CAR T cells was determined by co-culture assays with different glioma cells. Efficacy of CAR T cells to control tumor growth in vivo was investigated in clinically relevant orthotopic xenograft glioma mouse models. Additionally, we generated CAR T cells from T cells from a glioblastoma patient and measured their activity against the patient’s autologous tumor cells.

Results

All newly generated integrin-targeting CAR T cells exerted strong anti-glioma activity in vitro. Long-term and repetitive killing assays as well as cytokine-release measurements demonstrated highest activity of αvβ5 and αvβ8 integrin-specific CAR T cells. Antigen specificity of these cells was confirmed, as glioma cells with a CRISPR/Cas9-mediated knockout of the target antigen were resistant to CAR T cell-mediated cytotoxicity. Intratumoral injection of αvβ5 or αvβ8 CAR T cells significantly prolonged the survival and cured a substantial fraction of glioma-bearing mice in two different xenograft models. When used in a patient-derived setting, matched CAR T cells exerted strong anti-glioma activity.

Conclusion

We show strong and integrin-specific anti-glioma activity of CAR T cells developed from healthy donor T cells and glioblastoma-patient-derived T cells in vitro. αvβ5- and αvβ8-specific CAR T cells exerted the best therapeutic activity in two different xenograft glioma models in vivo. These data support the evaluation of integrin-specific CAR T cells as a therapeutic strategy in clinical neuro-oncology.
OS09.4.A Cognitive functioning of patients with diffuse glioma during stable disease
Authors: Gorter M , Röttgering J G , Belgers V , van Lingen M R , De Witt Hamer P C , Douw L , Klein M
Published: September 2022

Background

Glioma patients often experience cognitive problems, which are associated with decreased functional independence and health-related quality of life. However, the prevalence and nature of cognitive impairment in these patients is relatively underreported, particularly during stable disease. In this study we determine the prevalence of cognitive deficits and explore distinct cognitive profiles of patients with diffuse glioma at least two months after tumor treatment.

Material and Methods

A total of 112 patients (mean age: 43 years) without clinical or radiological progression with a grade II-IV glioma were included in this observational cohort study. Cognitive functioning was assessed in five cognitive domains (attention, information processing speed, verbal memory, working memory, and executive functioning). Cognitive impairment was defined as a z-score of 1.5 SD below that of healthy controls. Hierarchical cluster analysis was used to examine cognitive profiles.

Results

In total, 46 patients (41%) had cognitive impairment. More than one domain was impaired in 25 of these patients (54%). The domains were affected in decreasing order of frequency: working memory in 31%, information processing speed in 22%, attention in 19%, verbal memory in 12%, and executive functioning in 11% of the patients. A clustered heatmap revealed three prominent cognitive clusters with an increasing number of cognitive domains impaired. The first cluster displayed patients with only working memory deficits, patients in the second cluster also had deficits in information processing speed, and the last cluster showed patients with impairments across all domains.

Conclusion

Cognitive impairment is highly prevalent in patients with diffuse glioma during stable disease. Working memory and information processing speed are most frequently affected. Importantly, our analyses show evidence for three subgroups in cognitively impaired glioma patients. Working memory seems an important driver in cognitive impairment given the involvement in all subgroups.
OS11.4.A Intrathecal delivery of dendritic cell vaccine eradicates tumor growth and protects against leptomeningeal disease re-inoculation in immunocompetent HER2+ and triple negative breast cancer leptomeningeal disease xenograft models
Authors: Law V , Kodumudi K , Snyder C , Czerniecki B , Forsyth P
Published: September 2022

Background

Leptomeningeal disease (LMD) occurs in ~5% of patients with breast cancer (BC) and has a median survival of 2-4 months. We found a loss of the anti-HER2 and anti-HER3 CD4 Th1 immune responses in BC patients. In pre-clinical and clinical trials the administration of class II HER2 peptide-pulsed dendritic cell vaccine (HER2-DCV) partially restores anti-HER2 Th1 immune responses with pathologic complete responses in HER2+ BC patients. Here, we examined the intrathecal (IT) delivery of HER2/HER3-DCV in BC-LMD immunocompetent animal models.

Material and Methods

Luciferase-labeled HER2+ TUBO BCs were injected into the cisterna magna of BALB/c mice to produce LMD. We used our Murine Ommaya (mimics an Ommaya reservoir clinically in patients) for the IT administration of DCVs into the cerebral spinal fluid (CSF).

Results

BC-LMD mice were randomized into following groups: 1) HER2-DCV IT 2) HER3-DCV IT 3) HER2/HER3-DCV IT. The median survival of untreated (control) group was 15 days. All groups given DCV IT prolonged survival (p<0.001). Interestingly, HER2-/HER3-DCV IT was able to rescue disease mice (71% in HER2+ BC-LMD and 28% in triple negative breast cancer-LMD) and showed complete tumor regression. Some surviving mice were immune to subsequent tumor rechallenge. In mice CSF, we found evidence of CD4+ and CD8+ T-cells infiltration, and robust IFN-gamma and IL18 response upon DCV treatment.

Conclusion

Our preclinical data supported a clinical trial (submitted) of the IT delivery of DCV in BC patients with LMD.
OS11.5.A Utility of lumbar puncture (LP) and cerebrospinal fluid (CSF) profile in the diagnosis of neoplastic meningitis (NM): a retrospective cohort study and meta-analyses
Authors: Tuohy K J , Major K , Aregawi D , Glantz M
Published: September 2022

Background

CSF cytology remains the gold standard for diagnosing NM, but the sensitivity of this test is low (approximately 50% with one LP). Little is known about the predictive value of routine CSF and clinical findings for a positive cytology. We addressed these questions by analyzing 337 consecutive patients at our institution, and by conducting exhaustive evidence-based literature reviews and meta-analyses of relevant research.

Material and Methods

337 consecutive patients at a single institution were evaluated. Of these, 210 met criteria for NM (a positive CSF cytology on at least one of four pre-treatment samples) or no NM (four consecutive negative CSF cytologies). CSF white blood cell count, glucose, protein, and lactate were collected, as well as the presence of neurological symptoms. Optimal threshold values were identified using ROC curves. Sensitivity (Sn), specificity (Sp), and likelihood ratios were calculated for each variable. Two PRISMA-compliant meta-analyses were also performed: one analyzed studies reporting the cytology results of multiple LPs, and one analyzed the frequency of abnormal CSF findings as predictors of NM.

Results

All published results describe outcomes in patients with known NM. These results are, therefore, strongly distorted by spectrum bias, which artificially inflates the apparent sensitivity and specificity of those outcomes. Thus, 25 studies report the yield of positive CSF cytology on the first, second, and third LP as 73%, 87%, and 94%, but also do not describe the parameters of the procedure. Our series in patients with suspected NM (the cohort most relevant to the practicing physician) reports 74%, 85%, and 92% for immediately processed, 10 mL or greater, lumbar and ventricular specimens. Similarly, while 50 studies suggested that low CSF glucose, high CSF protein, and suggestive symptoms are associated with NM, we found very poor Sn/Sp for elevated protein (61%/61%), low glucose (35%/85%), elevated lactate (35%/91%), and symptoms consistent with NM (74%/73%). Of these values, only an elevated lactate and symptoms were even marginally helpful in predicting a positive CSF cytology. No variable predicted a negative cytology, and 22.8% of patients with a positive CSF cytology had completely normal CSF findings.

Conclusion

Generally accepted concepts about the frequency of CSF and clinical findings in patients with suspected NM are based on biased estimates in the literature. No CSF chemistry or clinical finding reliably predicts the presence of NM, and almost a quarter of patients with cytologically proven NM have completely normal findings. In patients with positive CSF cytologies, about 73% are detected after one LP, and more than 90% after 3, but again these findings represent overestimates because of pervasive spectrum bias and differences in sample acquisition/handling. Better diagnostic techniques are desperately needed.