Araştırma Çıktıları

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    Information theory approaches to improve glioma diagnostic workflows in surgical neuropathology
    (WILEY, 2022-01-01) Cevik, Lokman; Landrove, Marilyn Vazquez; Aslan, Mehmet Tahir; Khammad, Vasilii; Garagorry Guerra, Francisco Jose; Cabello-Izquierdo, Yolanda; Wang, Wesley; Zhao, Jing; Becker, Aline Paixao; Czeisler, Catherine; Rendeiro, Anne Costa; Sousa Veras, Lucas Luis; Zanon, Maicon Fernando; Reis, Rui Manuel; Matsushita, Marcus de Medeiros; Ozduman, Koray; Pamir, M. Necmettin; Danyeli, Ayca Ersen; Pearce, Thomas; Felicella, Michelle; Eschbacher, Jennifer; Arakaki, Naomi; Martinetto, Horacio; Parwani, Anil; Thomas, Diana L.; Otero, Jose Javier
    Aims Resource-strained healthcare ecosystems often struggle with the adoption of the World Health Organization (WHO) recommendations for the classification of central nervous system (CNS) tumors. The generation of robust clinical diagnostic aids and the advancement of simple solutions to inform investment strategies in surgical neuropathology would improve patient care in these settings. Methods We used simple information theory calculations on a brain cancer simulation model and real-world data sets to compare contributions of clinical, histologic, immunohistochemical, and molecular information. An image noise assay was generated to compare the efficiencies of different image segmentation methods in H\&E and Olig2 stained images obtained from digital slides. An auto-adjustable image analysis workflow was generated and compared with neuropathologists for p53 positivity quantification. Finally, the density of extracted features of the nuclei, p53 positivity quantification, and combined ATRX/age feature was used to generate a predictive model for 1p/19q codeletion in IDH-mutant tumors. Results Information theory calculations can be performed on open access platforms and provide significant insight into linear and nonlinear associations between diagnostic biomarkers. Age, p53, and ATRX status have significant information for the diagnosis of IDH-mutant tumors. The predictive models may facilitate the reduction of false-positive 1p/19q codeletion by fluorescence in situ hybridization (FISH) testing. Conclusions We posit that this approach provides an improvement on the cIMPACT-NOW workflow recommendations for IDH-mutant tumors and a framework for future resource and testing allocation.
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    Oligosarcomas, IDH-mutant are distinct and aggressive
    (SPRINGER, 2022-01-01) Suwala, Abigail K.; Felix, Marius; Friedel, Dennis; Stichel, Damian; Schrimpf, Daniel; Hinz, Felix; Hewer, Ekkehard; Schweizer, Leonille; Dohmen, Hildegard; Pohl, Ute; Staszewski, Ori; Korshunov, Andrey; Stein, Marco; Wongsurawat, Thidathip; Cheunsuacchon, Pornsuk; Sathornsumetee, Sith; Koelsche, Christian; Turner, Clinton; Le Rhun, Emilie; Muhlebner, Angelika; Schucht, Philippe; Ozduman, Koray; Ono, Takahiro; Shimizu, Hiroaki; Prinz, Marco; Acker, Till; Herold-Mende, Christel; Kessler, Tobias; Wick, Wolfgang; Capper, David; Wesseling, Pieter; Sahm, Felix; von Deimling, Andreas; Hartmann, Christian; Reuss, David E.
    Oligodendrogliomas are defined at the molecular level by the presence of an IDH mutation and codeletion of chromosomal arms 1p and 19q. In the past, case reports and small studies described gliomas with sarcomatous features arising from oligodendrogliomas, so called oligosarcomas. Here, we report a series of 24 IDH-mutant oligosarcomas from 23 patients forming a distinct methylation class. The tumors were recurrences from prior oligodendrogliomas or developed de novo. Precursor tumors of 12 oligosarcomas were histologically and molecularly indistinguishable from conventional oligodendrogliomas. Oligosarcoma tumor cells were embedded in a dense network of reticulin fibers, frequently showing p53 accumulation, positivity for SMA and CALD1, loss of OLIG2 and gain of H3K27 trimethylation (H3K27me3) as compared to primary lesions. In 5 oligosarcomas no 1p/19q codeletion was detectable, although it was present in the primary lesions. Copy number neutral LOH was determined as underlying mechanism. Oligosarcomas harbored an increased chromosomal copy number variation load with frequent CDKN2A/B deletions. Proteomic profiling demonstrated oligosarcomas to be highly distinct from conventional CNS WHO grade 3 oligodendrogliomas with consistent evidence for a smooth muscle differentiation. Expression of several tumor suppressors was reduced with NF1 being lost frequently. In contrast, oncogenic YAP1 was aberrantly overexpressed in oligosarcomas. Panel sequencing revealed mutations in NF1 and TP53 along with IDH1/2 and TERT promoter mutations. Survival of patients was significantly poorer for oligosarcomas as first recurrence than for grade 3 oligodendrogliomas as first recurrence. These results establish oligosarcomas as a distinct group of IDH-mutant gliomas differing from conventional oligodendrogliomas on the histologic, epigenetic, proteomic, molecular and clinical level. The diagnosis can be based on the combined presence of (a) sarcomatous histology, (b) IDH-mutation and (c) TERT promoter mutation and/or 1p/19q codeletion, or, in unresolved cases, on its characteristic DNA methylation profile.