Longitudinal experience with WHO Grade III (anaplastic) meningiomas at a single institution.

To retrospectively analyze and assess the outcomes and prognostic factors in patients with anaplastic meningioma (AM) (WHO Grade III). Clinical data and outcome [overall (OS) and progression-free (PFS) survival] from 18 patients with Grade III meningioma (AM, based on World Health Organization 2016 definition) initially treated between March 2000 and June 2015 were analyzed. Eleven patients (61%) were male, median age at diagnosis was 63 (range 48-86), and 55% (10/18 patients) had good performance status (KPS ≥ 80). Eight patients (45%) had lower grade disease (Grade I-n = 2; Grade II-n = 6) prior to being upgraded to AM. Ten patients had fractionated radiation after primary surgery, eight patients had salvage fractionated RT, stereotactic radiosurgery (SRS) boost along with primary RT in 1 patient, and salvage SRS to 18 separate areas in 14 patients. Salvage chemotherapy was mainly considered in third or fourth recurrences. 13 (72%) patients recurred and 10 (56%) have died. Median PFS was 14.5 months (95% CI 6.9-22.2). The 5-year survival rate was 40 ± 15% and median OS was 55.8 months (95% CI 27.7-80.3). Of all factors examined, only Karnofsky performance status (KPS) affected outcome (PFS p = 0.0003; OS p = 0.0003). With median OS of 55 months (4.6 years) our results are consistent with existing reports of the poor outcomes for AM patients. From the available data, surgical resection followed by RT and salvage radiosurgery and/or chemotherapy can lead to extended survival; however the benefit may decrease with successive treatments.