title: World Health Organization grade II meningiomas.
abstract: BACKGROUND
  We analyzed WHO grade II meningioma cases to identify factors influencing survival.
  
  
  METHODS
  Between January 2000 and August 2015, 206 cases of World Health Organization (WHO) grade II meningioma were operated at our institution. This population underwent a total of 298 surgical resections and 55 patients received a radiotherapy. A Cox multivariate regression was conducted on clinical and histological criteria.
  
  
  RESULTS
  Sixty-four patients were deceased (31.1 %), of which 38 died following the disease progression (18.4 %). Overall survival probability at 1, 5, and 10 years were 95.4 %, 95 % CI [92.5, 98.4]; 84 %, 95 % CI [78.3, 90.2], and 72.9 %, 95 % CI [64.5, 82.4], respectively (Fig. 1a). At the end of the study, only 87 patients (42.2 %) were alive with no tumor residual or recurrence on the last scan. Age at diagnosis (hazard ratio (HR) = 0.31, 95 % CI [0.15, 0.63], p < 0.001), extent of resection (HR = 0.25, 95 % CI [0.12, 0.49], p < 0.001), and tumoral brain invasion (HR = 0.49, 95 % CI [0.25, 0.98], p = 0.040) were independent factors associated with the overall survival. The patients who received radiotherapy did not demonstrate a longer overall survival (p = 0.540).
  
  
  CONCLUSIONS
  WHO grade II meningioma significantly impaired the survival of the patients. In the adjusted Cox regression, a macroscopic gross total resection (Simpson grades 1, 2, and 3), an age below 62 years at diagnosis and the absence of brain invasion were independent factors associated with a longer survival. Radiotherapy may not increase the overall survival after complete or incomplete resection.
authors.affiliation: Department of Neurosurgery, Institute of Neurological Sciences, Southern General Hospital, 1345 Govan Road, Glasgow, G51 4TF, UK. charles.champeaux@gmail.com.
authors.forename: Charles
authors.identifier: http://orcid.org/0000-0002-0356-0893
authors.initials: C
authors.lastname: Champeaux
authors.affiliation: Department of Neurosurgery, Institute of Neurological Sciences, Southern General Hospital, 1345 Govan Road, Glasgow, G51 4TF, UK.
authors.forename: Laurence
authors.initials: L
authors.lastname: Dunn
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000145:classification / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D008579:Meningioma / Q000145:classification / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D008875:Middle Aged; D060787:Neoplasm Grading; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000706:statistics & numerical data; D016019:Survival Analysis; D014944:World Health Organization
keywords: Atypical meningioma; Outcome; Prognostic factors; Radiotherapy; Survival; WHO grade II meningioma