NCOG-50. CLINICAL AND GENOMIC FACTORS ASSOCIATED WITH SEIZURES IN MENINGIOMAS

Abstract Clinical and genomic sequencing data of 394 patients surgically treated for meningioma were reviewed to better understand the relationship between seizures and meningiomas. Correlations of clinical and genomic variables and occurrence of preoperative (PRESZ) and postoperative (POSTSZ) seizures were analyzed. 17% of patients presented with PRESZ and used AEDs preoperatively for 46.5 months on average as they were more likely to be treated in the setting of a recurrent tumor (p = 0.042). PRESZ patients were at higher risk for worse progression free survival (HR 2.68, 95% CI 1.30-5.50) and were also more likely to have meningiomas with an NF2-mutation (p = 0.032), higher grade (p = 0.030) and brain invasion (p = 0.009). On multivariate analysis, edema (OR 3.11, 95% CI 1.46-6.65; p = 0.003) and atypical histology (OR 2.00, 95% CI 1.03-3.90; p = 0.041) were positive predictors of PRESZ, while genomic subgroup was not, such that the effect of NF2 mutation was indirectly mediated through atypical histology and edema (p = 0.012). Seizure freedom was achieved in 83.3% of the cohort. 20% of all seizure-free patients were able to discontinue AED use postoperatively and they were more likely to have undergone a GTR (p = 0.031). Edema (OR 13.69, 95% CI 1.19-14.88; p = 0.026), recurrent tumors (OR 7.41, 95% CI 1.27-8.68; p = 0.015), and postoperative radiation (OR 6.37, 95% CI 1.16-7.53; p = 0.023) were significant predictors of POSTSZ. Hedgehog-pathway mutated tumors were associated with POSTSZ in Grade I meningiomas (p = 0.026). While NF2-mutated tumors are significantly associated with PRESZ, this appears due to corresponding edema and atypical histology. Patients who undergo radiation and/or suffer recurrence are at risk for POSTSZ, irrespective of extent of resection. PRESZ may portend a more potentially aggressive molecular entity and challenging clinical course with higher recurrence risk.