title: Atypical meningioma: randomized trials are required to resolve contradictory retrospective results regarding the role of adjuvant radiotherapy.
abstract: BACKGROUND
  The role of postoperative radiation (RT) in atypical meningioma remains controversial.
  
  
  METHODS
  We report a retrospective review of outcomes and prognostic factor analysis in 158 patients treated between 2000 and 2010, and extensively review the literature.
  
  
  RESULTS
  Following resection, 23 patients received immediate RT, whereas 135 did not. Median progression-free survival (PFS) with and without RT was 59 (range 43-86) and 88 (range 64-123) months. For Simpson grade (G) 1-3 resection, with and without RT, median PFS was 48 (2-80) versus 96 (88-123) months and for Simpson G4, it was 59 (6-86) versus 47 (15-104) months (P = 0.4). The rate of 5-year overall survival (OS) with and without RT was 89% and 83%, respectively. On univariate analysis, Simpson G4 (HR 3.2, P = 0.0006) and brain invasion (HR 2.2, P = 0.03) were significantly associated with progression, whereas age >60 years (HR 9.7, P = 0.002), mitoses >5 per 10 high-power field (0.2, P = 0.0056), and Simpson G4 (HR 2.4, P = 0.07) were associated with higher risk of death. We summarized 22 additional reports, which provide very divergent results regarding the benefit of RT.
  
  
  CONCLUSIONS
  In our series, adjuvant RT is surprisingly associated with worse PFS and OS, and this is more likely to be due to selection bias of referring tumors with more aggressive characteristics such as elevated Ki-67 and brain invasion for adjuvant RT, rather than a direct causal effect of adjuvant RT. Although there is a trend toward improved PFS with adjuvant RT after subtotal resection, no improvement was noted in OS. Multivariate analysis did not yield statistical significance for any of the factors including Simpson grades of resection, adjuvant RT, or six pathological defining features. The relatively divergent results in the literature are most likely explained by patient selection variability; therefore, randomized trials to adequately address this question are clearly necessary.
authors: Hannah
authors: H
authors: Yoon
authors: Minesh P
authors: MP
authors: Mehta
authors: Karthikeyan
authors: K
authors: Perumal
authors: Irene B
authors: IB
authors: Helenowski
authors: Richard J
authors: RJ
authors: Chappell
authors: Erinc
authors: E
authors: Akture
authors: Yunzhi
authors: Y
authors: Lin
authors: Mary Anne H
authors: MA
authors: Marymont
authors: Samir
authors: S
authors: Sejpal
authors: Andrew
authors: A
authors: Parsa
authors: James R
authors: JR
authors: Chandler
authors: Bernard R
authors: BR
authors: Bendok
authors: Joshua
authors: J
authors: Rosenow
authors: Shahriar
authors: S
authors: Salamat
authors: Priya
authors: P
authors: Kumthekar
authors: Jeffrey K
authors: JK
authors: Raizer
authors: Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin, USA.
authors: Mustafa K
authors: MK
authors: Baskaya
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008579:Meningioma / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D011182:Postoperative Care; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D016032:Randomized Controlled Trials as Topic; D019233:Retreatment; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome