COT-1 Clinical Questions and Answers about Glioma-Related Epilepsy (GRE): Real-world data in Wakayama Medical University Hospital

Introduction: In glioma patients, epilepsy not infrequently occurred and anti-epileptic drugs (AEDs) are commonly used. In this study, we revealed the real-world data on clinical practice of glioma-related epilepsy in Wakayama Medical University Hospital (WMUH). Methods. We collected clinical and molecular data of glioma patients operated at WMUH from January 1996 to December 2020 and analyzed the data to answer clinical questions as follows: 1) location/histology related GRE, 2) molecular features related GRE, 3) prophylactic AEDs and postoperative seizure, 4) tumor progression and convulsion, 5) GRE and survival. Results. Fifty-five of 113 glioma patients (49%) presented with seizure. CQ1. In tumors located at frontal, temporal and parietal lobe, the occurrence rate of GRE was 27/39 (69%), 13/19 (69%) and 9/14 (64%), respectively. Patients with glioblastoma, astrocytic tumors and oligodendroglial tumors presented with GRE at the rate of 26/54 (48%), 14/30 (47%) and 12/13 (92%), respectively. CQ2. GRE occurred in tumors with IDH mutated (16 cases, 29%), TERT mutated (32 cases, 58%) and MGMT methylated (32 cases, 58%). CQ3. Seizure in peri- or postoperative period occurred in 14 cases (12%); 4 cases in AED(+) group (4/29, 14%) and 10 cases in AED(-) group (10/84, 12%). CQ4. Tumor progression became apparent at the time of seizure in 12 cases (12/55, 22%). CQ5. According to the prognostic IDH/TERT classification of diffuse glioma cases (n = 94), overall survival (OS) times of GRE(+) cases tended to be longer than that of GRE(-) ones, especially in IDH wildtype/TERT mutated group (22.7 months vs. 8.3 months, p = 0.0397). Conclusion. GRE is likely associated with specific clinical and molecular features. Seizure in glioma patients can occur in specific situation regardless of the use of AEDs. Possible better prognosis of GRE(+) cases requires further investigation.