bluuebunny/crossref_metadata_2025_split huggingface dataset:
P11.73.B The diagnostic value of frame-based stereotactic biopsies in the age of precision oncology: A cross-sectional study
Authors: Alhalabi O T , Sahm F , Unterberg A W , Jakobs M 
Published: September 2022

Abstract

Background
For non-resectable, eloquent, multifocal and deep-seated intracranial lesions, stereotactic frame-based biopsies can deliver a finite amount of tissue for neuropathology studies. With the increasing role of molecular genetics in the diagnostics of intracranial tumors, sufficient tissue for sequencing studies is of paramount importance. This study explored the rate of successful diagnosis after stereotactic frame-based biopsies of intracranial lesions in a high-throughput neurooncology center

Material and Methods
145 consecutive patients undergoing frame-based stereotactic biopsies in 2020 and 2021 at our neurosurgical department were included in this retrospective analysis. Aspects of histological and molecular (methylomics, panel-sequencing) neuropathology analysis in addition to clinical and radiological variables were analyzed. Cases were classified as conclusive, likely-conclusive (sufficient diagnosis with non-satisfying sequencing information), and inconclusive neuropathological diagnosis.

Results
Of 145 cases analyzed, astrocytic tumors were suspected in n= 94 (67%) of patients. In n= 122 cases (84%), a conclusive diagnosis was possible. For 14 (11%) cases, a likely-conclusive diagnosis was established Diagnoses comprised mainly WHO 4 glioblastomas (56%), WHO 3 gliomas (2%) in addition to WHO 1 and 2 gliomas (n=7, 5%), CNS lymphomas (n=23, 16%), inflammatory diseases (n=10, 7%) and normal or reactive tissue (n=4, 3%). Methylomics were pivotal in providing an integrated diagnosis in 30% of the cases (panel sequencing in 14%). In n= 12 (8%) of the cases further testing was hindered by insufficient tissue sample DNA. Only in 3 out of 12 cases this resulted in a final inconclusive diagnosis.

Conclusion
Although stereotactic frame-based biopsies deliver a limited amount of tissue, they bear an excellent histopathological and molecular genetic diagnostic yield, with rare cases of missing molecular data or rarely insufficient diagnosis. Optimizing the number and representativeness of cell and DNA-rich stereotactic biopsy specimen might enhance the diagnostic and therapeutic potential of precision oncology even further.
P11.76.A Retrospective evaluation of Overall Survival and Progression Free Survival in patients with glioblastoma comparing 6 vs 12 cycles of Adjuvant Temozolomide
Authors: Martinez Perez, 1993 D , Debén Méndez, 1993 B , Rodríguez Roldán M , Garrido Botella, 1993 M , García Cuesta, 1993 J , Pedregosa Barbas, 1993 J , Vilches Aguirre Y , Martinez Marin V 
Published: September 2022

Abstract

Background
The standard of care for glioblastoma multiforme (GBM) is surgery followed by adjuvant concomitant chemo-radiotherapy and adjuvant temolomide (TMZ) for 6 cycles. Extending the duration of adjuvant TMZ did not demonstrate an overall survival (OS) benefit in a meta-analysis including 2214 GBM patients. A phase II randomized clinical trial including 166 GBM patients compared 6 vs 12 cycles of TMZ, showing no differences in progression-free-survival (PFS), although MGMT methylated patients showed better outcomes. The objective of this study is to analyze PFS and OS of GMB patients receiving 6 vs 12 cycles of adjuvant TMZ.

Material and Methods
Patients with a pathological diagnosis of GBM between 1 December 2016 and 31 December 2020 in a single center (Hospital Universitario La Paz) were retrospectively reviewed. Inclusion criteria were confirmed pathological diagnosis and patients receiving multimodality treatment (surgery, radiation and chemotherapy). Two cohorts were analyzed, cohort A patients receiving 6 cycles of adjuvant TMZ and cohort B patients receiving 12 cycles of adjuvant TMZ. Statistical analysis was performed via SPSS v.21 (differences between both cohorts were calculated using χ² and T Student and survival outcomes with Kaplan Meier curves, comparing its differences using log-rank test).

Results
Sixty-eight patients were included in the final analysis, with a median age of 58 years at diagnosis. Fourty-two patients (62%) received 6 cycles of adjuvant TMZ (cohort A), whereas 26 patients (38%) received 12 cycles (cohort B). Median OS was 10 months for cohort A and 20 months for cohort B (p&lt;0,001), median PFS was 8 months for cohort A and 19 months for cohort B (p=0,001). No significant differences were shown between both cohorts regarding age at diagnosis, being 60 years in cohort A and 54 years in cohort B (p = 0,06), and positive-margins after surgery (p=0,796), being 9,5% and 7,7% respectively in each cohort. Significant differences were found regarding MGMT methylation (30% in cohort A and 68% in cohort B).

Conclusion
In our study, patients receiving 12 cycles of adjuvant TMZ had better median OS and median PFS, compared to patients receiving 6 cycles, although the latter group had significantly less MGMT methylated patients, which is a known prognostic and predictive factor of response to TMZ.
P12.05.B Impact of GAP-43 and actin expression on the outcome and overall survival in diffuse and anaplastic gliomas
Authors: Krigers A , Demetz M , Moser P , Kerschbaumer J , Brawanski K R , Thomé C , Freyschlag C F 
Published: September 2022

Abstract

Background
Distant intercellular communication in gliomas is based on the expansion of tumor microtubuli (TMs), where actin forms cytoskeleton and GAP-43 mediates the axonal conus growth. We aimed to investigate the impact of GAP-43 and actin expression on overall survival (OS) as well as crucial epidemiologic, radiological and neuropathological prognostic factors.

Material and Methods
FFPE tissue of adult patients with diffuse and anaplastic gliomas, who underwent first surgery in our center between 2010 and 2019, were selected. GAP-43 and actin expression was analyzed using immunohistochemistry and semi-quantitatively ranked. Clinical, neuropathological as well as follow-up-data were gained from the institutional neuro-oncological database.

Results
118 patients with a median age of 46 years (IqR: 35 - 57) were evaluated. 48 (41%) presented with a diffuse glioma and 70 (59%) revealed anaplasia. 96 (82%) cases presented with intermediate or strong GAP-43 expression and 78 (67%) with no or light actin expression. Tumors with higher expression of GAP-43 (p=0.024, HR=1.71/rank) and actin (p&lt;0.001, HR=2.28/rank) showed significantly reduced OS. IDH wildtype glioma demonstrated significantly more expression of both proteins: GAP-43 (p=0.009) and actin (p&lt;0.001). The same was confirmed for anaplasia (GAP-43 p=0.028, actin p=0.029), higher proliferation rate (GAP-43 p=0.016, actin p=0.038), contrast-enhancement in MRI (GAP-43 p=0.023, actin p=0.037) and age (GAP-43 p=0.004, actin p&lt;0.001).

Conclusion
The intercellular distant communication network in diffuse and anaplastic gliomas formed by actin and GAP-43 is associated with a negative impact on overall survival and unfavorable prognostic features.
P12.08.A Uncovering the glioblastoma tumor-microenvironment by high-end multiplexing with imaging mass cytometry
Authors: Anand A , Harwood D S , Bishop C , Todd K , Ellis R , Ellis R , Poulsen F R , Kristensen B W 
Published: September 2022

Abstract

Background
Glioblastoma is one of the most aggressive cancers, and hypoxia plays an essential role in its tumor- microenvironment. Tumor-associated microglia and macrophages (TAMs) have been reported to constitute up to 30 % of the cells, a fraction that is even higher in hypoxic areas. Single-cell mRNA sequencing of glioblastoma tumors has revealed vast heterogeneity, but the spatial aspects are not entirely defined yet. The aim of this study was to uncover differences between the hypoxic and normoxic tumor-microenvironment of human glioblastoma by high-end multiplexing with imaging mass cytometry.

Material and Methods
A tissue microarray (TMA) with normoxic and hypoxic areas from 4 IDH-wildtype glioblastomas was prepared based on the hypoxia marker hypoxia-inducing factor 1 alpha (HIF1 alpha). The TMA was stained with 18 metal-tagged antibodies covering TAMs, lymphocytes, immune checkpoints, vessels, tumor cells and proliferation. The Hyperion-CYTOF technology was used to ablate the samples and the images were analyzed by MCD viewer, Visiopharm software, and customized R scripts.

Results
Single-cell analysis of 160 fields covering around 45,000 cells in the glioblastoma microenvironment revealed multiple cellular phenotypes. It was revealed that proliferating TAMs (IBA1+, Ki67+) were more frequent in hypoxia, whereas proliferating vessels (CD34+, Ki67+) were more frequent in normoxia. Additionally, proliferating stem-like tumor cells (OLIG-2+, Ki67+) were more frequent in normoxia regions.

Conclusion
Our study revealed multiple cellular phenotypes in the glioblastoma microenvironment. The TAMs, endothelial and tumor cell phenotypes revealed may play a critical role in glioblastoma biology however this needs to be elucidated in future studies.
P12.12.A Resolving the cellular architecture of infiltration zones in glioblastoma
Authors: Ritter M , Blume C , Patel A , Sievers P , Dogan H , Herold-Mende C , Wick W , von Deimling A , Sahm F 
Published: September 2022

Abstract

Background
Therapy resistance and infiltration still pose major challenges in the treatment of glioma. In the tumour border niche, an interaction between different healthy cell types and malignant cells leads to therapy resistance, acquisition of stem-cell like features, and recurrence. However, studying the tumour border is quite challenging due to the lack of specific glioma markers. Although single cell datasets contain information about the abundance of different cell types, they still lack the spatial arrangement at the border niche. Spatial transcriptomic approaches might overcome these problems, but are still limited by a low resolution or a limited number of detectable transcripts.

Material and Methods
We applied the Visium spatial transcriptomics platform on 18 FFPE and 11 fresh frozen gliomas to image the cellular architecture of the tumour border niche. In addition, the transcriptome of single nuclei isolated from the fresh frozen sections was also analysed. Using Seurat and a single cell reference set from Darmanis et al. (2017) the cell types were mapped onto the section and the copy number variation profile (CNV) was determined.

Results
Using a single cell reference set we were able to map different cell types onto different areas of the tumour border niche of gliomas. To control the mapping the expression of cellular markers was used to detect healthy brain cells and the CNV profile was used to identify the tumour. The mapping matched the expression of markers and the CNV profile and only showed minor differences. First analysis confirmed distinct distribution of oligodendrocytes and neurons at the tumour border. We could not detect an enrichment of any tumour subtypes at the tumour border so far. However, one sample showed an enrichment of the mesenchymal subtype at the perinecrotic region. CNVs also showed low intratumoural heterogeneity for most sections.

Conclusion
Although the first results of the mapping of different cell types look promising, a larger reference set including a larger variety of cell types and tumour subtypes could improve the mapping even further. Nevertheless, we were able to show the cell type distribution at the tumour border and generate robust CNVs for most sections using spatial transcriptomics.
P13.03.A Radiomics for the non-invasive assessment of the PDL-1 expression in patients with non-small cell lung cancer brain metastases
Authors: Meißner A , Gutsche R , Galldiks N , Kocher M , Jünger S , Eich M , Nogova L , Schmidt N , Ruge M , Goldbrunner R , Proescholdt M , Grau S , Lohmann P 
Published: September 2022

Abstract

BACKGROUND
The expression level of programmed cell death ligand 1 (PDL-1) might be an indicator for response to immunotherapy using checkpoint inhibitors in patients with non-small cell lung cancer (NSCLC). As intra-tumoral differences and discrepancies between the PDL-1 expression in the primary tumor and the brain metastases may occur, a method for a reliable non-invasive assessment of the intracranial PDL-1 expression would be of clinical value. We evaluated the potential of MRI radiomics for a non-invasive assessment of the PDL-1 expression in patients with NSCLC brain metastases.

PATIENTS AND METHODS
Fifty-three patients with brain metastases from NSCLC from two university brain tumor centers (group 1, 36 patients; group 2, 17 patients) underwent tumor resection with subsequent immunohistochemical assessment of the PDL-1 expression. Brain metastases were manually segmented on preoperative T1-weighted contrast-enhanced MRI. Group 1 was used for model training and validation, group 2 for model testing. After image pre-processing and radiomics feature extraction from T1-weighted contrast-enhanced MRI, a test-retest analysis was performed to identify robust features prior to feature selection. The radiomics model was trained and validated using five-fold cross validation. Finally, the best performing radiomics model was applied to the test data. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analyses.

RESULTS
An intracranial PDL-1 expression was found by immunohistochemistry in 18 of 36 patients (50%) in group 1, and 7 of 17 patients (41%) in group 2. Univariate analysis identified tumor volume as a significant clinical feature for PDL-1 expression (area under the ROC curve (AUC), 0.77). A random forest classifier using a four-parameter radiomics signature including tumor volume yielded an AUC of 0.83 ± 0.18 in the training data (group 1). Finally, the classifier achieved an AUC of 0.84 in the external test data (group 2).

CONCLUSION
The developed radiomics classifiers allows a non-invasive assessment of the intracranial PD-L1 expression in patients with NSCLC brain metastases with a high diagnostic performance.
P14.01.B Isolation and characterization of circulating tumor cells in a glioblastoma case with recurrence at distance and correlation with tumor mutational status
Authors: Lessi F , Morelli M , Aretini P , Menicagli M , Franceschi S , Pasqualetti F , Gambacciani C , Di Stefano A , Santonocito O , Mazzanti C M 
Published: September 2022

Abstract

Background
Circulating Tumor Cells (CTCs) are considered to be one of the important causes of tumor recurrence and distant metastasis. For many years, glioblastoma (GB) was thought to be restricted to the brain. Nevertheless, a growing body of evidence indicates that, like many other cancers, hematogenic dissemination is a reality. The absence of a procedural uniformity in literature prompted us to develop an innovative and sensitive method to obtain CTCs in GB. Our aim is to define the genetic background of single CTCs compared with the primary GB tumor and its recurrence to assess whether or not their presence in the peripheral circulation correlates with GB migration and dissemination.

Material and Methods
CTCs were enriched from whole blood of one patient with recurrent GB with Parsortix Cell Separation System and analysed on DEPArray system. After that, CTCs Copy Number Aberrations (CNAs) and sequencing analysis was performed to compare CTCs genetic background with the same patient’s primary and recurrence tissues, analysed by NextSeq 500 (whole exome sequencing).

Results
We obtained 211 mutations in common between primary and recurrence tumor. Among these, three somatic mutations (c.430 G&gt;A in PRKCB gene, c.815 C&gt;T in TBX1 gene and c.1554 T&gt;G in COG5 gene) were selected to investigate their presence in recurrence CTCs. Almost all of the sorted CTCs (9/13) had at least one of the mutations tested.

Conclusion
In confirmation of the hypothesis, the CTCs detected in the patient's blood were actually cancer cells deriving from GB tumor.
P14.04.A TrackingTERTpromoter andIDH1mutations in liquid biopsies - suitable biomarkers for disease monitoring in glioma patients?
Authors: Bruckner K , Madlener S , Lang A , Kiesel B , Furtner-Srajer J , Hainfellner J , Haberler C , Spiegl-Kreinecker S , Dorfer C , Slavc I , Gojo J , Rössler K , Lötsch-Gojo D 
Published: September 2022

Abstract

Background
Mutations within the telomerase reverse transcriptase promoter (TERTprom) and isocitrate dehydrogenase (IDH) account for the most common genetic alterations in gliomas. Each of these mutations impact clinicopathologic diagnosis and course of diseases. While TERTprom mutations are frequently detected in glioblastoma, IHD mutations are assigned to astrocytoma of grade 2-4, thus mostly associated with better prognosis. In the era of precision oncology, molecular profiling and continuous monitoring of treatment response or relapse are of increasing importance. Accordingly, this study aims to detect TERTprom and IDH mutations in plasma-derived cell-free (cf)DNA of gliomas. The mutant allele frequencies (MAF) will be compared retrospectively to clinico-pathological parameters including extent of resection and tumor progression.

Material and Methods
Digital droplet PCR (ddPCR) analyses were performed using the QX200TM Digital Droplet System from BioRad. First, to evaluate probes for ddPCR, genomic DNA of several brain tumor cell models (n=6) and tumor tissue (n=1), as well as cfDNA of plasma (n=3) from samples with known TERTprom and IDH mutation status was investigated. For detection of IDH mutations, the unique assay ID dHSaMDV2010055 (IDH1p.R132H) and for TERTprom mutations the TaqMan dPCR Liquid Biopsy Assays for C228T (Hs000000092) and C250T (Hs000000093) were used. The results of ddPCR were analyzed with QuantaSoftTM software and the MAF was calculated

Results
To validate the detection method for IDH1R132H, we analyzed the MAF in one tissue and corresponding plasma sample of a confirmed IDH1-mutated astrocytoma. In addition, plasma from one astrocytoma grade 2-3 as well as from an IDH1-mutated glioblastoma was tested. Interestingly, both astrocytoma cases exhibited undetectable or very low MAF ranging from 0.1 to 1% in tissue as well as in plasma samples, while in plasma from the high-grade glioblastoma case, IDH1R132H was detected with a frequency of 1.9%. Due to the high GC content of the TERT promoter region, amplification steps are challenging. Accordingly, we first optimized ddPCR conditions for C228T and C250T probes by adding 7-deaza-2-deoxyguanosine-5-triphosphate (7-ddGTP) in varying concentrations to each ddPCR reaction. When using 4µM of 7-ddGTP per sample, a clear separation between mutant and wild-type droplets was reached, detecting MAF between 36-63% in DNA from cell culture models.

Conclusion
Within this pilot study we optimized the ddPCR method for the detection of IDH1R132H and TERTprom mutations in plasma and tissue samples. Subsequently, we hypothesize that these mutations are suitable liquid biomarkers correlating with extent of resection and tumor progression in gliomas.
P15.02.B Spatial habitat analysis in high-grade gliomas combining perfusion, diffusion, and hypoxia features derived from multiparametric MRI and 18F-FAZA PET
Authors: Bailo M , Pecco N , Callea M , Scifo P , Gagliardi F , Fallanca F , Picchio M , Mortini P , Falini A , Castellano A 
Published: September 2022

Abstract

Background
Heterogeneity represents one of the main issues in high-grade gliomas (HGGs) management and presumably is the key to understanding treatment failure. Spatial habitat imaging embodies a novel, non-invasive method to cluster different tumor biological microenvironments and characterize intratumoral heterogeneity through a quantitative radiomic approach. So far, habitat imaging has been chiefly explored on morphological magnetic resonance imaging (MRI): the aim of our study was to evaluate this technique on advanced imaging techniques as perfusion (PWI) and diffusion (dMRI) MRI, as well as 18F-FAZA PET, to subdivide the tumor into different biological compartments.

Materials and Methods
A preoperative PWI, dMRI, and 18F-FAZA PET acquisition was obtained in 17 HGG patients to assess intratumoral vascularization, cellularity, and hypoxia, respectively. A tumor mask was created including contrast-enhancing/necrotic regions on T1 imaging and surrounding FLAIR hyperintensity, and each parametric map (plasma volume from dynamic contrast-enhanced PWI, mean diffusivity from diffusion tensor imaging, and standardized uptake value from 18F-FAZA PET) underwent OTSU’s binary clustering by grouping together voxels with high and low-intensity values. Cluster intersections were then generated by combining all possible high and low-intensity regions of each map, and the final habitat map was composed. Habitats’ quantitative features, spatial distribution, and histopathological characteristics were analyzed.

Results
The eight habitats generated were carefully inspected, and their distribution pattern, in relation to morphological landmarks (as contrast-enhancing, necrotic, infiltrative and edematous areas), showed an excellent reproducibility among different HGGs, offering complementary data to conventional imaging. A consistent correlation was noted between each habitat’s awaited microenvironment and the corresponding histopathological characteristics among the ten patients for whom precise coordinates of stereotactic biopsies were available. Clusters considered more aggressive were more represented in WHO grade IV (vs. grade III) tumors. The habitat possibly representing edematous areas was significantly larger in IDH-1 wild-type (vs. IDH-1 mutated) tumors.
Conclusions: PET and MRI hypoxia, perfusion, and tissue diffusion habitat maps proved an excellent reproducibility among HGGs and correlation with expected histopathological features, making it a way to characterize intratumoral heterogeneity. However, further study is needed to elucidate clinical implications and confirm the spatio-temporal evolution of the identified habitats.

Funding
Italian Ministry of Health, grant number GR-2018-12365670; Italian Association for Cancer Research (grant IG 2014 Id.1524).