Long term follow up in 183 high grade meningioma: A single institutional experience.

INTRODUCTION: Meningiomas are usually considered benign lesions, however a proportion of them shows a more aggressive behavior, defined high-grade meningiomas (HGM). Effective medical treatments are lacking, especially at the time of recurrence.

METHODS: Through a retrospective analysis, we examined epidemiological, diagnostic, therapeutic, recurrence information and survival data of HGM treated at our institution between 2010 and 2018.

RESULTS: 183 patients (105 females and 78 males), with median age of 58 years (25-88), were included; 168 were atypical, 12 anaplastic, 3 rhabdoid. Overall, m-PFS was 4.2 years, and m-OS was 10.3 years. Gross-total resection had a 5-year survival rate of 95% compared with subtotal/partial resection (86% and 67%) (p = 0.002). Higher expression of Ki-67/MIB-1 seems associated with higher risk of death (HR:1.06 with 95% CI, 1.00-1.12, p = 0.03). No statistically significant differences were seen in survival between the group managed with a wait-and-see strategy vs the group treated with RT while a difference on PFS was seen (4.1 years vs 5.2 years p = 0.03). After second recurrence, the most employed treatments were systemic therapies with a very limited effect on disease control.

CONCLUSIONS: Data confirmed the aggressive behavior of HGM. The extent of resection seems to correlate with a favorable outcome regardless histological subtypes. The role of RT remains controversial, with no statistically significant impact on OS but a possible role on PFS. Recurrent HGM remains the real challenge, to date no chemotherapies are able to achieve disease control. Future research should focus on biological/molecular predictors in order to achieve a patient-tailored treatment.