Between January 2000 and August 2015, 178 cases of World Health Organisation (WHO) Grade II meningioma were operated.
This population underwent a total of 224 surgical resections and 36 patients received a radiotherapy. Median follow-up was 3.6 years, inter-quartile ranges (IQR)[1.5 - 6.2].
28 patients (16.1%) were re operated for a relapse of their grade II meningioma. The median time between the first and the second surgery was 4.2 years, IQR[1.4-5.3]. Surgical recurrence-free survival at 1, 2, 5 and 10 years were respectively: 96.9%, 95 %CI[94.2, 99.6]; 91.7%, 95 %CI[87.3, 96.3], 85%, 95 %CI[78.6, 92] and, 70.8%, 95 %CI[60.1,83.5].At the end of the study, 93 patients (57.8%) had no residual tumour on the last scan. Age at diagnosis (HR=0.17, 95 %CI[0.05,0.56], p-value<0.001), extent of resection (HR=0.22, 95 %CI[0.08,0.64], p-value=0.01), and Ki-67 index (HR=0.18, 95 %CI[0.06,0.56], p-value<0.001) were independent factors associated with the surgical recurrence-free survival.
Younger patients with a lower proliferation rate and gross total resection are less likely to undergo a re intervention for WHO grade II meningioma recurrence. Observation rather than systematic adjuvant radiotherapy may be preferred. If possible, a redo surgery may be considered in case of relapse or tumour residual progression, as radiotherapy may not decrease the surgical recurrence-free survival after complete or incomplete resection 1).