Recurrence of surgically treated parasagittal meningiomas: a meta-analysis of risk factors.

BACKGROUND: As the predictive role of many risk factors for parasagittal meningioma (PM) recurrence remains unclear, the objective of the meta-analysis was to make a comprehensive assessment of the predictive value of selected risk factors in these lesions. METHODS: Studies including data on selected risk factors, such as histology, tumor and sinus resection, sinus invasion, tumor localization, and immediate postoperative radiotherapy for PMs recurrence, were searched in the NCBI/NLM PubMed/MEDLINE, EBM Reviews/Cochrane Central, ProQuest, and Scopus databases, and analyzed using random effects modeling. RESULTS: Thirteen observational studies involving 1243 patients met the criteria for inclusion in the meta-analysis. WHO grading of meningiomas was identified as the most powerful risk factor for recurrence. WHO grade II meningiomas (OR 11.61; 95% CI 4.43-30.43; P < .01; I(2) = 31%) or composite group of WHO grades II and III (OR 14.84; 95% CI 5.10-43.19; P < .01; I(2) = 48%) had a significantly higher risk of recurrence than benign lesions. Moreover, an advanced sinus involvement (types IV-VI according to the Sindou classification) (OR 3.49; 95% CI 1.30-9.33; P = .01; I(2) = 0%) and partial tumor resection (Simpson grades III-V) (OR 2.73; 95% CI 1.41-5.30; P = .03; I(2) = 52%) were associated with a significantly higher risk of recurrence than their counterparts. CONCLUSION: Among the selected risk factors, high-grade WHO lesions, advanced sinus invasion, and partial tumor resection were associated with a higher risk of PM recurrence, with WHO grading system being the most powerful risk factor.