Recurrence After Subtotal Resection of NF-2-Associated Versus Sporadic Vestibular Schwannomas: A Matched-Cohort Analysis.

Abstract

This study compares recurrence patterns after subtotal resection (STR) of neurofibromatosis type 2 (NF-2)-associated versus sporadic vestibular schwannomas (VSs) and aims to identify independent predictors of recurrence. Retrospective matched-cohort study. Single tertiary academic medical center. We identified patients who underwent STR for VS between 2004 and 2024. A cohort of 21 NF-2 patients was matched to 79 sporadic controls based on age, sex, and tumor size (Koos grade). Preoperative and postoperative tumor volumes were calculated and included as covariates in survival analyses. The primary outcome was recurrence-free survival, analyzed using Kaplan-Meier methods and Cox proportional hazards regression. The NF-2 cohort experienced a higher overall recurrence rate than the matched sporadic cohort (42.9% vs 16.5%). In a multivariable Cox regression model adjusting for clinical and volumetric covariates, NF-2 status emerged as a strong, significant independent predictor of recurrence (adjusted hazard ratio [aHR] 4.83; 95% CI 1.25-18.62; P = .022). This association was absent in the full, unmatched cohort, highlighting the importance of the matched design. No other variables, including postoperative adjuvant radiation, were significant predictors in the final matched model. In this matched-cohort analysis, the intrinsic biology of germline NF2 is a powerful, independent driver of tumor recurrence following STR. This finding, unmasked by controlling for key confounders, suggests that the elevated recurrence risk in NF-2 patients is a direct consequence of the underlying genetic disorder. These results underscore the distinct natural history of NF-2-associated tumors and support the need for lifelong surveillance.