Introduction: Anaplastic meningiomas are rare, comprising only 1-2% of all meningiomas. As such there is limited data on its natural history and response to treatment. A consensus on the optimal way to treat anaplastic meningiomas is required.
Methods: An international retrospective study was designed to characterise the clinical course of anaplastic meningiomas and the influence of current treatments. The 2016 Classification of the Tumours of the CNS was used to identify grade 3 meningiomas. Anonymised clinical and radiological data were collected in a uniform manner from 21 centres internationally.
Results: 355 patients were identified to have an anaplastic meningioma. The average age at presentation was 67.5+35.9 years. The majority of patients were female 58.8%. 59% of these were de novo tumours. In progressive tumours, 69.4% underwent one resection prior to transforming into a malignant tumour; 19.7% underwent 3 or more surgical resections prior to malignant transformation. The mode Glasgow outcome score (GOS) was 5 in the pre-anaplastic cohort. 51% of pre-anaplastic tumours were treated with adjuvant radiotherapy. The mode Simpson grade was 2 in this cohort. After transformation 68.5% of patients underwent one surgery. The mode GOS was 4 after the first surgery and second surgery. 61.4% of anaplastic patients received radiotherapy. The mode Simpson resection was 3. Further analyses are in progress.
Conclusions: Here in we present the first international and the largest ever assembled cohort of patients with anaplastic meningiomas.
Patient Care: In the the first international and the largest ever assembled cohort of patients with anapaestic meningiomas these results are likely to direct future patient management.
Learning Objectives: To learn about the role of surgery on anaplastic meningiomas.
To learn about the role of radiotherapy on anaplastic meningiomas.
To learn about outcome of patients with anaplastic meningiomas.