gms | German Medical Science

Objective: Anaplastic meningiomas World Health Organization (WHO) Grade III meningiomas are rare and represent 1%–2% of all meningiomas. They are characterized by significant morbidity and mortality. Anaplastic meningiomas are nowadays considered either to arise de novo (primary anaplastic meningiomas: PAM) or to progress from a lower-grade tumor (secondary anaplastic meningiomas: SAM). In this study, we sought to analyze clinical parameters that may influence progression-free (PFS) and overall survival (OS) following treatment of PAM and SAM.

Methods: Clinical data from patients who underwent resection of an anaplastic meningioma between 1995 and 2018 were evaluated. Kaplan-Meier and Cox regression analyses were performed to determine the impact of different clinical characteristics and different treatment modalities on survival.

Results: We identified 29 patients with an anaplastic meningioma (10 female and 19 male patients). The median age at first diagnosis was 70 years (23 – 85 years). Ten patients had a SAM and 19 patients a PAM. The majority of tumors (n= 18, 62%) were located at the brain convexity. While complete resection (Simpson Grade I) was achievable in 84% (n = 16) of the primary anaplastic meningiomas, only 60% of the secondary anaplastic meningiomas received a complete resection. The PFS of SAM patients was significantly shorter (12.3 months, 95% CI 3.1 – 21.5) compared with PAM patients (56.1 months, 95% CI 0.5 – 119.6, p= .004). All patients received radiotherapy, while only three patients received an adjuvant chemotherapy. In the multivariate analysis, none of the treatment modalities nor other demographic or clinical factors showed a significant influence on patients’ outcome (PFS and OS).

Conclusion: Our study highlights the different prognoses of de novo and secondary anaplastic meningiomas. Moreover, it demonstartes that surgery is an effective treatment for secondary and primary anaplastic meningiomas.