Hints for reclassification of meningiomas based on the fifth edition of WHO CNS.

Abstract

e14059 Background: Meningioma is the most common primary neoplasm of the central nervous system (CNS) in adults. Genetic variants ( NF2, AKT1, TRAF7 etc.) are strongly related to the subtypes of meningioma. TERT promoter mutation or homozygous CDKN2A and/or CDKN2B deletion are independent evidence for diagnosing WHO grade 3 meningioma according to 5th CNS WHO. Our study reclassifies meningiomas using a clinical and molecular real-world dataset. Methods: This study retrospectively analyzed the genomic alteration of 347 Chinese meningioma patients during 2019-2022. Next-generation sequencing (NGS) was performed to detect gene mutations in tumor samples. Results: TERT promoter mutation or CDKN2A/B deletion were identified in 11% (n = 39) of patients ( TERT 5.2%, CDKN2A 8.1%, CDKN2B 8.6%). Of these cases, histologic grade information was available for 26 patients, 14(53.8%) of whom were reclassified as WHO grade 3 meningiomas, including four histologic grade 1 and ten histologic grade 2. There is a male preponderance in reclassified patients (56.4% vs. 40.0%, p < 0.05), meanwhile the age showed no significant difference between them (average age: 54 vs 50, p = 0.11). The most frequently co-mutated gene was NF2. The proportion of TERT promoter mutation or CDKN2A/B deletion in NF2-mutant tumors was similar to NF2-wildtype tumors (10% vs. 11%, p > 0.05). Conclusions: In our study, 11% of Chinese adult meningioma patients found TERT promoter mutation or CDKN2A/B deletion and showed a male preponderance, among 53.8% of whom were reclassified as meningiomas WHO grade 3. Overall, these data advance the understanding of the significance of molecular profiling in the classification of meningioma patients according to the 5th WHO CNS.