Clinical and methylomic features of spinal meningiomas

Purpose: The objective of our study was to analyze methylomic and clinical features of a cohort of spinal meningiomas (SMs) resected at our institution. Methods: This is a retrospective study of patients undergoing SM resection at our institution between 2010 and 2023. Clinical and radiographic characteristics were reviewed and analyzed with standard statistical methods. A Partitioning Around Medoids approach was used to cluster SMs with methylation data in a combined cohort from our institution and a publicly available dataset by methylation profiles. Clinical variables and pathway analyses were compared for the resulting clusters. Results: Sixty-five SMs were resected in 53 patients with median radiographic follow-up of 34 months. Forty-six (87%) patients were female. The median age at surgery was 65 years and median tumor diameter was 1.9 cm. The five-year progression-free survival rate was 90%, with subtotal resection being associated with recurrence or progression (p =.017). SMs clustered into hypermethylation, intermediate methylation, and hypomethylation subgroups. Tumors in the hypermethylated subgroup were associated with higher WHO grade (p =.046) and higher risk histological subtypes (p <.001), while tumors in the hypomethylated subgroup were least likely to present with copy-number loss in chromosome 22q (p <.0001). SMs classified as immune-enriched under a previously developed intracranial meningioma classifier did not have increased leukocyte fractions or hypomethylation of genes typically hypomethylated in immune-enriched tumors. Conclusion: SMs are more benign than their intracranial counterparts, and gross-total resection results in long term PFS. Methylation profiling identifies subgroups with differences in clinical variables.