title: Concordance between local, institutional, and central pathology review in glioblastoma: implications for research and practice: a pilot study.
abstract: BACKGROUND
  There is significant inter-observer variation amongst the neuro-pathologists in the typing, subtyping, and grading of glial neoplasms for diagnosis. Centralized pathology review has been proposed to minimize this inter-observer variation and is now almost mandatory for accrual into multicentric trials. We sought to assess the concordance between neuro-pathologists on histopathological diagnosis of glioblastoma.
  
  
  METHODS
  Comparison of local, institutional, and central neuro-oncopathology reporting in a cohort of 34 patients with newly diagnosed supratentorial glioblastoma accrued consecutively at a tertiary-care institution on a prospective trial testing the addition of a new agent to standard chemo-radiation regimen.
  
  
  RESULTS
  Concordance was sub-optimal between local histological diagnosis and central review, fair between local diagnosis and institutional review, and good between institutional and central review, with respect to histological typing/subtyping. Twelve (39%) of 31 patients with local histological diagnosis had identical tumor type, subtype and grade on central review. Overall agreement was modestly better (52%) between local diagnosis and institutional review. In contrast, 28 (83%) of 34 patients had completely concordant histopathologic diagnosis between institutional and central review. The inter-observer reliability test showed poor agreement between local and central review (kappa statistic=0.12, 95% confidence interval (CI): -0.03-0.32, P=0.043), but moderate agreement between institutional and central review (kappa statistic=0.51, 95%CI: 0.17-0.84, P=0.00003). Agreement between local diagnosis and institutional review was fair.
  
  
  CONCLUSIONS
  There exists significant inter-observer variation regarding histopathological diagnosis of glioblastoma with significant implications for clinical research and practice. There is a need for more objective, quantitative, robust, and reproducible criteria for better subtyping for accurate diagnosis.
authors.affiliation: Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer (ACTREC) and Tata Memorial Hospital, Tata Memorial Centre, Mumbai, India. tejpalgupta@rediffmail.com
authors.forename: Tejpal
authors.initials: T
authors.lastname: Gupta
authors.forename: Vimoj
authors.initials: V
authors.lastname: Nair
authors.forename: Sridhar
authors.initials: S
authors.lastname: Epari
authors.forename: Torsten
authors.initials: T
authors.lastname: Pietsch
authors.forename: Rakesh
authors.initials: R
authors.lastname: Jalali
mesh_terms: D001932:Brain Neoplasms / Q000453:epidemiology / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D005909:Glioblastoma / Q000453:epidemiology / Q000473:pathology*; D006801:Humans; D007325:Institutional Practice / Q000706:statistics & numerical data; D008297:Male; D015588:Observer Variation; D010338:Pathology, Clinical / Q000379:methods; D010865:Pilot Projects; D015203:Reproducibility of Results