BIOM-68. OUTCOMES IN PATIENTS WITH HIGH-GRADE MENINGIOMA (HGM): A MULTI-INSTITUTIONAL STUDY

Abstract BACKGROUND High-grade meningiomas (HGMs) are associated with increased risk of recurrence after primary treatment. This study aimed to evaluate factors affecting survival. METHODS We performed a multi-institutional retrospective chart review study of patients with HGM (defined as grade 2 or 3 meningioma) whose tumor had undergone next-generation sequencing. Statistical testing was performed in Stata/MP version 16.1 (StataCorp, College Station, TX) on the patients’ demographic, anatomic, clinical, and survival data (using Kaplan-Meier survivor function and long-rank test). Data are presented as mean±SD, median [interquartile range], or percent. Age/time reported in years. RESULTS There were 46 patients (45.7% female) with an age of 57.9±14.0 at initial HGM diagnosis. The most frequent HGM sites were middle cranial fossa (37.0%), frontal (28.3%), parietal (15.2%), posterior fossa (13.0%), parasagittal (10.9%), and petrous (10.9%). The most common presenting symptoms were headache (37.0%), seizure (23.9%), weakness (21.7%), vision changes (19.6%), memory issues (10.9%), and diplopia (10.9%). The most frequent gene mutations were in NF2 (58.7%), CDKN2A (13.0%), and TERT (8.7%). Median follow-up was 2.85 [1.4-7], during which time 65.2% of patients experienced recurrence. mPFS was 2.7 [0.83-6]. Kaplan-Meier analysis showed a mPFS of 5 [1.2-9] and 2.3 [0.8-3] in females and males, respectively (p=0.26). Age and Ki67 proliferative index at diagnosis did not significantly predict PFS. mOS was not reached (NR) [7-NR]. NF2 mutation status and presence of extracranial invasion did not significantly separate the PFS Kaplan-Meier curves on log-rank testing. However, the presence of NF2 mutation [mOS NR (5.2-NR) vs. NR (7-NR), p<0.0001], extracranial invasion [mOS 10 (2.4-NR) vs. NR (NR-NR), p<0.0001], and HGM recurrence [mOS NR (2.7-NR) vs. NR (7-NR), p<0.0001], were associated with shorter mOS. CONCLUSIONS These HGM patients experienced a high recurrence rate during the follow-up period. The presence of NF2 mutation, extracranial invasion, and recurrent HGM were associated with shorter OS.