Prognostic factors for first recurrence following meningioma surgery.

The present study investigated the role of the Simpson grade system, MIB-1 immunohistochemical marker, meningioma location and grade in the risk of recurrence. Between January, 2008 and January, 2018, the present study retrospectively evaluated all patients undergoing craniotomy for the resection of a histopathologically confirmed meningioma. Patients with neurofibromatosis, acoustic neurinomas and radiation treatment prior to surgery were excluded. After applying the exclusion criteria, 103 patients were included in the study. Following a mean follow-up period of 67.3±33 months, there were 12 cases (11.6%) of tumor recurrence. No significant association between meningioma recurrence and age, sex, or tumor location was found. When comparing the risk of recurrence between Simpson grades I, II, III and IV excisions, and between Simpson grade V, the difference was statistically significant. When comparing WHO grade I and II meningioma vs. grade III, the difference was significant. MIB-1 LI >3% exhibited a trend towards a significant association with the risk of recurrence. On the whole, the present study demonstrates that the Simpson grade is associated with the risk of recurrence. Patients with tumors with an MIB-1 index >3% may also be at a risk of recurrence. Notably, the present study proposed that in the case of recurrence, this is more likely to occur in an interval of 5.5 years following surgical intervention.