Atypical meningioma. A study on recurrence and disease-specific survival

Abstract

BackgroundTo analyse the outcome of patients with WHO grade II meningioma and identify factors that may influence recurrence and survival. Material and methodsBetween January 2000 and October 2016, a retrospective search identified 215 WHO grade II meningiomas operated on at our institution. A survival analysis was conducted on clinical and histological criteria. ResultsEighteen patients (8.4%) had a previous history of grade I meningioma. The cohort underwent a total of 302 surgical resections and 29.7% received radiotherapy. Forty-one patients (19.1%) had been re-operated on for a WHO grade II meningioma relapse. Median follow-up was 4.5 years. At the end of the study, 105 patients (53.6%) had no residual tumour on the last scan. Surgical recurrence-free survival at 5 years was 82%, 95% CI [75.9–88.5]. Secondary grade II meningioma (HR=4.27, P=0.001), Simpson resection grade 1 and 2 vs. 3, 4 and 5 (HR=0.25, P=0.001) and, Ki-67 index (HR=0.22, P<0.001) were independently associated with the surgical recurrence-free survival. Forty-four patients died from their tumours (20.5%). Cause-specific survival probability at 5 years was 83.2%, 95% CI [77.6–89.1]. Age at diagnosis (HR=0.31, P<0.001), Simpson resection grade 1 and 2 vs. 3, 4 and 5 (HR=0.32, P<0.001) and, redo surgery for recurrence (HR=2.39, P=0.010) were independently associated with the cause-specific survival. Patients who received radiotherapy did not demonstrate either a reduced risk of recurrence or a longer survival (P=0.280). ConclusionIn this large series, atypical meningioma recurrence correlated with progression from grade I to II, incomplete resection and high Ki-67 index; shorter survival with an older age, incomplete resection, and redo surgery for recurrence. We did not observe a significant improvement in any of the clinical outcomes after radiotherapy.