De novo and secondary anaplastic meningiomas: a study of clinical and histomolecular prognostic factors

Abstract

Background

Following recent studies underlining the differences between de novo and secondary anaplastic meningiomas and the prognostic value of TERT promoter mutation, we decided to conduct a multicenter retrospective study to address these questions and determine specific prognostic factors in each of these two anaplastic meningioma subgroups.

Methods

Among the 68 meningioma cases initially selected, only 57 were confirmed as anaplastic meningiomas after centralized pathological review. TERT promoter mutation analysis was performed in all cases.

Results

Median overall survival was 2.6 years and 5-year survival rate was 10%. This study confirmed the better prognosis of de novo anaplastic meningiomas (28 tumors) compared to secondary anaplastic meningiomas (29 tumors) (p=0.02). In the "de novo" group, meningiomas diagnosed on histological anaplasia alone had a better prognosis than patients with a high number of mitoses with or without anaplasia (p=0.01). In the "secondary" group, tumors demonstrate very heterogeneous clinical courses leading to malignant transformation and time to first relapse as a low grade tumor was a strong predictor of overall survival (p=0.0007). TERT promoter mutation in anaplastic meningiomas was rare (14%) and did not influence overall survival, but was associated with a shorter recurrence-free survival in the secondary anaplastic meningioma subgroup (p=0.02). The absence of TERT promoter methylation, although rare (3/33 cases), may be associated with prolonged overall survival (p=0.02).

Conclusion

This study highlights the different prognoses of de novo and secondary anaplastic meningiomas with specific prognostic factors in each subgroup. The analysis of TERT mutation and methylation could provide additional prognostic insights.