Methylation subgroup and molecular heterogeneity is a hallmark of glioblastoma: implications for biopsy targeting, classification and therapy

Background

Patients and methods

Results

Conclusions

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Glioblastoma exhibits significant heterogeneity, from epigenome-wide methylation phenotypes to single molecular targets.

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Phylogeny showed CDKN2A/B loss and gain of EGFR, PDGFRA, and CDK4 early in tumor development.

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Intratumoral heterogeneity is of utmost importance for molecular classification as well as for defining therapeutic targets.

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Assessing single biopsies underestimates the true molecular diversity in a tumor.

[Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]

BACKGROUND

Autopsies are a valuable tool for understanding disease, including COVID-19.

MATERIALS AND METHODS

The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs.

RESULTS

The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy.

CONCLUSIONS

Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.

Discrimination of Different Brain Metastases and Primary CNS Lymphomas Using Morphologic Criteria and Diffusion Tensor Imaging

Purpose: Brain metastases are a common complication of cancer and occur in about 15 - 40 % of patients with malignancies. The aim of this retrospective study was to differentiate between metastases from different primary tumors/CNS lymphyomas using morphologic criteria, fractional anisotropy (FA) and apparent diffusion coefficient (ADC). Materials and Methods: Morphologic criteria such as hemorrhage, cysts, pattern of contrast enhancement and location were reported in 200 consecutive patients with brain metastases/primary CNS lymphomas. FA and ADC values were measured in regions of interest (ROIs) placed in the contrast-enhancing tumor part, the necrosis and the non-enhancing peritumoral region (NEPTR). Differences between histopathological subtypes of metastases were analyzed using non-parametric tests, decision trees and hierarchical clustering analysis. Results: Significant differences were found in morphologic criteria such as hemorrhage or pattern of contrast enhancement. In diffusion measurements, significant differences between the different tumor entities were only found in ADC analyzed in the contrast-enhancing tumor part. Among single tumor entities, primary CNS lymphomas showed significantly lower median ADC values in the contrast-enhancing tumor part (ADC_lymphoma 0.92 [0.83 - 1.07] vs. ADC_{no_lymphoma} 1.35 [1.10 - 1.64] P = 0.001). Further differentiation between types of metastases was not possible using FA and ADC. Conclusion: There were morphologic differences among the main subtypes of brain metastases/CNS lymphomas. However, due to a high variability of common types of metastases and low specificity, prospective differentiation remained challenging. DTI including FA and ADC was not a reliable tool for differentiation between different histopathological subtypes of brain metastases except for CNS lymphomas showing lower ADC values. Biopsy, surgery and staging remain essential for diagnosis. Key Points: • Histopathological subtypes of brain metastases/CNS lymphomas show different morphologic features on MRI• Primary CNS lymphomas show significantly reduced ADC values• DTI is not a reliable tool for differentiation between brain metastases Citation Format: • Bette S, Wiestler B, Delbridge C et al. Discrimination of Different Brain Metastases and Primary CNS Lymphomas Using Morphologic Criteria and Diffusion Tensor Imaging. Fortschr Röntgenstr 2016; 188: 1134 - 1143.

Monoclonal antibody for identification of human duct cell carcinoma of pancreas

Monoclonal antibody to duct cell surface marker (HP-DU-1), produced by hybridoma, was shown to be specific to duct cell surface antigen when tested against normal adult and 12-20-week-old fetal human pancreases. There were no common HLA antigens for locus A, B, C and DR among the 10 pancreas donors; nor did HP-DU-1 reveal any affinity for lymphocytes of donors whose pancreases were used as antigen for immunization of BALB/c mice. Seven out of 7 human pancreas adenocarcinomas including a poorly differentiated human pancreatic tumor expressed surface determinants detectable by HP-DU-1. Cell lines CAPAN-1 and CAPAN-2, derived from human pancreatic adenocarcinoma, also revealed the same antigenic determinants.