Development and internal validation of a survival prediction model for grade II/III intracranial meningioma using NCDB data.

BACKGROUND: Meningiomas are the most common primary intracranial tumor, with high-grade (WHO grade II/III) meningiomas accounting for approximately 5% of cases. High-grade meningiomas have substantially worse survival compared to benign (grade I) meningiomas. Individualized prognostic tools for these tumors are scarce. In this study, we aimed to develop and internally validate a survival prediction model in patients with intracranial WHO grade II/III meningioma. METHODS: We conducted a retrospective cohort study using the National Cancer Database (NCDB) to identify adult patients diagnosed with WHO grade II or III intracranial meningioma between 2004 and 2023. A multivariable Cox proportional hazards model was developed using the full analytic cohort. Calibration was assessed at 1, 3, and 5 years by comparing predicted and observed overall survival (OS). Internal validation was performed with 300 bootstrap resamples. A prespecified treatment sensitivity model additionally examined radiotherapy (RT) and extent of surgery. RESULTS: The analysis included 1728 patients with WHO grade II or III meningioma (mean age, 59.6 years; 57.9% female). Of these patients, 1484 (85.9%) were grade II and 244 (14.1%) were grade III. Internal validation showed good discrimination, with an apparent concordance index (c-index) of 0.758 and an optimism-corrected c-index of 0.751. Optimism-corrected AUC scores were 0.774, 0.777, and 0.797 at 1, 3, and 5 years, respectively. Corresponding optimism-corrected Brier scores were 0.059, 0.111, and 0.143 at 1, 3, and 5 years, respectively. Global calibration was good (optimism-corrected calibration slope 0.966). A web-based calculator implementing the final model was developed for clinical use (https://019d02d0-e334-2c7e-dd4f-c8f3c99b76ac.share.connect.posit.cloud). CONCLUSIONS: We present an internally validated model for survival prediction at the time of diagnosis in WHO grade II/III meningioma, which could aid in personalized counseling and clinical decision-making for this aggressive tumor subset.