title: Overall survival benefit associated with adjuvant radiotherapy in WHO grade II meningioma.
abstract: BACKGROUND
  Adjuvant radiotherapy (RT) after surgical resection of World Health Organization (WHO) grade II meningioma, also known as atypical meningioma (AM), is a topic of controversy. The purpose of this study is to compare overall survival (OS) with or without adjuvant RT after subtotal resection (STR) or gross total resection (GTR) in AM patients diagnosed according to the 2007 WHO classification.
  
  
  METHODS
  The National Cancer Database was used to identify 2515 patients who were diagnosed with AM between 2009 and 2012 and underwent STR or GTR with or without adjuvant RT. Propensity score matching was first applied to balance covariates including age, year of diagnosis, sex, race, histology, and tumor size in STR or GTR cohorts stratified by adjuvant RT status. Multivariate regression according to the Cox proportional hazards model and Kaplan-Meier survival plots with log-rank test were then used to evaluate OS difference associated with adjuvant RT.
  
  
  RESULTS
  GTR is associated with improved OS compared with STR. In the subgroup analysis, adjuvant RT in patients who underwent STR demonstrated significant association with improved OS compared with no adjuvant RT (adjusted hazard ratio [AHR] 0.590, P = .045); however, adjuvant RT is not associated with improved OS in patients who underwent GTR (AHR 1.093, P = .737).
  
  
  CONCLUSIONS
  Despite the lack of consensus on whether adjuvant RT reduces recurrence after surgical resection of AM, our study observed significantly improved OS with adjuvant RT compared with no adjuvant RT after STR.
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: Chenyang
authors.initials: C
authors.lastname: Wang
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: Tania B
authors.initials: TB
authors.lastname: Kaprealian
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: John H
authors.initials: JH
authors.lastname: Suh
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: Charlotte D
authors.initials: CD
authors.lastname: Kubicky
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Ciporen
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: UCLA Department of Radiation Oncology, Los Angeles, California; Cleveland Clinic Department of Radiation Oncology, Cleveland, Ohio; Oregon Health & Science University Department of Radiation Medicine, Portland, Oregon; Oregon Health & Science University Department of Neurosurgery, Center for Health & Healing, Portland, Oregon; Oregon Health & Science University Department of Public Health & Preventive Medicine, Portland, Oregon.
authors.forename: Jerry J
authors.initials: JJ
authors.lastname: Jaboin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D008579:Meningioma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D019635:Neurosurgical Procedures; D057216:Propensity Score; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant / Q000379:methods*; D012189:Retrospective Studies
keywords: NCDB; WHO grade II meningioma; adjuvant radiotherapy; overall survival; propensity score