Purpose: WHO grade II meningiomas behave aggressively, with recurrence rates as high as 60%. Although complete resection in low-grade meningiomas is associated with a relatively low recurrence rate, the impact of complete resection for WHO grade II meningiomas is less clear. We studied the association of extent of resection with overall and progression-free survivals in patients with WHO grade II meningiomas.
Methods: A retrospective database review was performed to identify all patients who underwent surgical resection for intracranial WHO grade II meningiomas at our institution between 1995 and 2019. Kaplan-Meier analysis was used to compare overall and progression-free survivals between patients who underwent gross total resection (GTR) and those who underwent subtotal resection (STR). Multivariable Cox proportional-hazards analysis was used to identify independent predictors of tumor recurrence and mortality.
Results: Of 214 patients who underwent surgical resection for WHO grade II meningiomas (median follow-up 53.4 months), 158 had GTR and 56 had STR. In Kaplan-Meier analysis, patients who underwent GTR had significantly longer progression-free (p = 0.002) and overall (p = 0.006) survivals than those who underwent STR. In multivariable Cox proportional-hazards analysis, GTR independently predicted prolonged progression-free (HR 0.57, p = 0.038) and overall (HR 0.44, p = 0.017) survivals when controlling for age, tumor location, and adjuvant radiation.
Conclusions: Extent of resection independently predicts progression-free and overall survivals in patients with WHO grade II meningiomas. In an era of increasing support for adjuvant treatment modalities in the management of meningiomas, our data support maximal safe resection as the primary goal in treatment of these patients.
Keywords: Atypical meningioma; Extent of resection; Overall survival; Progression-free survival; Simpson grade; WHO grade II meningioma.