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Permanent URI for this communityhttps://hdl.handle.net/20.500.14288/2
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Publication Restricted Identification of chromatin related genes regulating temozolomide resistance in GBM(Koç University, 2019) Şenbabaoğlu, Filiz; Önder, Tuğba Bağcı; 0000-0003-3646-2613; Koç University Graduate School of Health Sciences; 184359
Publication Metadata only Pleomorphic xanthoastrocytoma: multi-institutional evaluation of stereotactic radiosurgery(Lippincott Williams and Wilkins, 2024) Nabeel AM, Reda WA, Tawadros SR, Abdelkarim K, El-Shehaby AMN, Emad RM, Martínez Moreno N, Martínez Álvarez R, Mathieu D, Niranjan A, Lunsford LD, Wei Z, Shanahan RM, Liscak R, May J, Dono A, Blanco AI, Esquenazi Y, Dayawansa S, Sheehan J, Tripathi M, Shepard MJ, Wegner RE, Upadhyay R, Palmer JD, Peker S.; Düzkalır, Ali Haluk; ; School of Medicine; Koç University HospitalBackground and objectives: Pleomorphic xanthoastrocytoma (PXA) is a rare low-grade glial tumor primarily affecting young individuals. Surgery is the primary treatment option; however, managing residual/recurrent tumors remains uncertain. This international multi-institutional study retrospectively assessed the use of stereotactic radiosurgery (SRS) for PXA. Methods: A total of 36 PXA patients (53 tumors) treated at 11 institutions between 1996 and 2023 were analyzed. Data included demographics, clinical variables, SRS parameters, tumor control, and clinical outcomes. Kaplan-Meier estimates summarized the local control (LC), progression-free survival, and overall survival (OS). Secondary end points addressed adverse radiation effects and the risk of malignant transformation. Cox regression analysis was used. Results: A total of 38 tumors were grade 2, and 15 tumors were grade 3. Nine patients underwent initial gross total resection, and 10 received adjuvant therapy. The main reason for SRS was residual tumors (41.5%). The median follow-up was 34 months (range, 2-324 months). LC was achieved in 77.4% of tumors, with 6-month, 1-year, and 2-year LC estimates at 86.7%, 82.3%, and 77.8%, respectively. Younger age at SRS (hazard ratios [HR] 3.164), absence of peritumoral edema (HR 4.685), and higher marginal dose (HR 6.190) were significantly associated with better LC. OS estimates at 1, 2, and 5 years were 86%, 74%, and 49.3%, respectively, with a median OS of 44 months. Four patients died due to disease progression. Radiological adverse radiation effects included edema (n = 8) and hemorrhagic change (n = 1). One grade 3 PXA transformed into glioblastoma 13 months after SRS. Conclusion: SRS offers promising outcomes for PXA management, providing effective LC, reasonable progression-free survival, and minimal adverse events.Publication Open Access Towards development of a standard terminology of the World Health Organization Classification of tumors of the central nervous system in the Turkish Language, and a perspective on the practical implications of the WHO classification for low and middle income countries(Buluş Design, 2022) Söylemezoğlu, Figen; Öz, Büge; Eğilmez, Reyhan; Pekmezci, Melike; Bozkurt, Süheyla; Danyeli, Ayça Ersen; Öngürü, Önder; N/A; Tihan, Tarık; Kulaç, İbrahim; Other; Faculty Member; School of Medicine; 307927; 170305In our manuscript, we propose a common terminology in the Turkish language for the newly adopted WHO classification of the CNS tumors, also known as the WHO CNS 5th edition. We also comment on the applicability of this new scheme in low and middle income countries, and warn about further deepening disparities between the global north and the global south. This division, augmented by the recent COVID-19 pandemic, threatens our ability to coordinate efforts worldwide and may create significant disparities in the diagnosis and treatment of cancers between the “haves” and the “have nots”.Publication Restricted Understanding of tumor heterogeneity in glioblastoma multiforme cell lines with differential apoptotic threshold(Koç University, 2019) Cingöz, Ahmet; Önder, Tuğba Bağcı; 0000-0003-3646-2613; Koç University Graduate School of Health Sciences; 184359