Predictors of Survival in Atypical Meningiomas

SIMPLE SUMMARY: Meningiomas are the most common intracranial tumor [1] and are classified by the World Health Organization (WHO) as grade I (benign), grade II (atypical), or grade III (anaplastic) [2]. Regarding atypical meningiomas, predictors of overall survival (OS) and progression-free survival (PFS) are less well documented compared to their benign counterparts. Moreover, one of the most critical aspects of meningiomas is tumor relapse/progression that may also take place after the complete removal of the lesion. Recurrent lesions pose the question whether it is reasonable to perform second surgery. Alternative approaches include radiotherapy (RT) (stereotactic radiosurgery or conventional fractionated RT). We investigated 77 consecutive patients who underwent craniotomy for intracranial atypical meningiomas to evaluate predictors of OS and retreatment-free survival, and to assess the benefits of surgical retreatment for subsequent recurrences. We concluded that gross total resection (GTR) significantly prolonged retreatment-free survival but had no significant impact on OS. GTR was also associated with improved/stable neurological outcomes at 6–12 months. Age at surgery, preoperative Karnofsky performance scale (KPS), and retreatment were all strong prognostic factors of OS. Time-to-retreatment did not decrease significantly in patients requiring repeated surgical excision. ABSTRACT: Introduction: Predictors of survival and progression of disease in atypical meningiomas are less well documented in the literature compared to benign meningiomas. Higher grade meningiomas tend to recur often and one of the most critical aspects is how to best deal with relapses. Methods: A total of 77 consecutive patients who underwent craniotomy for atypical meningioma between 1990–2010 at Oslo University Hospital (OUH) were reviewed. Results: Median age at surgery was 62.21 [interquartile range (IQR): 22.87] years. Fifty-one patients (66.2%) had neurological deficits at presentation. Fifty-four patients (70.1%) underwent gross total resection (GTR). Thirty-nine patients (50.7%) had improved/stable neurological outcomes at 6–12 months. Twenty-two patients (28.6%) underwent retreatment, of whom 20 (26.0%) were subjected to resection followed by adjuvant radiotherapy. Overall survival (OS) was significantly longer in patients <65 years (p < 0.001), with preoperative Karnofsky performance scale (KPS) score of ≥ 70 (p = 0.006), and who required no retreatment (p = 0.033). GTR significantly prolonged the retreatment-free survival rate (p < 0.001). STR carried almost a six-fold greater risk of neurological outcome deterioration (p = 0.044). Conclusions: GTR significantly prolonged retreatment-free survival but had no significant impact on OS. STR was a significant risk factor for deteriorated neurological outcome. Age, preoperative KPS, and retreatment were all strong predictors of OS. Median time-to-retreatment (TTR) did not shorten significantly throughout repeated surgeries.