Extent of Resection as the Primary Independent Predictor of Progression- Free Survival in Atypical Intracranial Meningioma: A Retrospective Single- Center Study of 187 Patients

Abstract Purpose Atypical meningiomas (WHO grade 2) show considerable biological heterogeneity and substantial recurrence rates despite surgical treatment, while reliable prognostic markers remain limited. We aimed to identify clinical and radiographic predictors of progression-free survival (PFS) in a large single-center cohort. Methods We retrospectively analysed 187 patients with histopathologically confirmed atypical intracranial meningioma (2016–2023), categorised by extent of resection (gross total resection [GTR] vs subtotal resection [STR]) and treatment strategy (surgery alone vs surgery plus radiotherapy). Kaplan–Meier and univariate/multivariate Cox regression were applied to identify predictors of PFS. Results GTR was achieved in 168 patients (89.8%) and STR in 19 (10.2%); tumor progression or recurrence occurred in 25 patients (13.4%). On multivariate analysis, extent of resection was the only independent predictor of shortened PFS (adjusted HR 3.09, 95% CI 1.14–8.37; p = 0.026). Peritumoral edema showed a consistent, non-significant trend toward shortened PFS (adjusted HR 2.43, 95% CI 0.92–6.37; p = 0.072). Age (HR 0.84, 95% CI 0.37–1.92; p = 0.7) and radiotherapy (HR 0.99, 95% CI 0.43–2.26; p > 0.9) were not significantly associated with PFS. Edema was not associated with the extent of resection or radiotherapy administration. Conclusion Extent of resection is the strongest independent predictor of PFS in atypical intracranial meningioma, reaffirming maximal safe resection as the central surgical objective. Peritumoral edema showed a consistent but non-significant trend that warrants confirmation in larger, adequately powered multicenter cohorts.