title: Inherent grading characteristics of individual pathologists contribute to clinically and prognostically relevant interobserver discordance concerning Broders' grading of penile squamous cell carcinomas.
abstract: BACKGROUND
  We assessed the reproducibility and prognostic impact of the Broders' grading system (BGS) in a cohort of 147 patients with surgically treated penile squamous cell carcinomas.
  
  
  METHODS
  Conventionally stained histology slides were graded according to the BGS in two rounds by two study pathologists. Reproducibility was assessed using ĸ statistics. Multivariable analyses were calculated to predict cancer-specific survival (CSS). The 'mean grade' per pathologist per round was calculated by allocating grade points to each study case (G1-G4: 1-4 points) and dividing the sum of all grade points by the number of cases examined.
  
  
  RESULTS
  The BGS showed substantial interobserver variation (59-87% with ĸ = 0.38-0.69) but almost perfect intraobserver reproducibility (91% with ĸ = 0.86 and 96% with ĸ = 0.94, respectively). The 'mean grade' per pathologist remained nearly constant in both rounds of examination (differences ≤0.05 grade points) but differed between the two pathologists (up to 0.4 grade points). In multivariable analyses, the prognostic impact of the BGS in terms of CSS was strongly pathologist-dependent.
  
  
  CONCLUSIONS
  Clinically and prognostically relevant interobserver discordance concerning the BGS seems, at least in part, to be attributable to inherent 'aggressive' versus 'reserved' grading characteristics of individual pathologists.
authors.affiliation: Institute of Pathology, Johanniter Hospital Stendal, Stendal, Germany. sven-gunia @ gmx.de
authors.forename: Sven
authors.initials: S
authors.lastname: Gunia
authors.forename: Maximilian
authors.initials: M
authors.lastname: Burger
authors.forename: Oliver W
authors.initials: OW
authors.lastname: Hakenberg
authors.forename: Dieter
authors.initials: D
authors.lastname: May
authors.forename: Stefan
authors.initials: S
authors.lastname: Koch
authors.forename: Anjun
authors.initials: A
authors.lastname: Jain
authors.forename: Kristina
authors.initials: K
authors.lastname: Birnkammer
authors.forename: Wolf F
authors.initials: WF
authors.lastname: Wieland
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Otto
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Hofstädter
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Fritsche
authors.forename: Stefan
authors.initials: S
authors.lastname: Denzinger
authors.forename: Christian
authors.initials: C
authors.lastname: Gilfrich
authors.forename: Sabine
authors.initials: S
authors.lastname: Brookman-May
authors.forename: Matthias
authors.initials: M
authors.lastname: May
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D015588:Observer Variation; D010336:Pathology / Q000592:standards*; D010412:Penile Neoplasms / Q000175:diagnosis* / Q000473:pathology; D010413:Penis / Q000473:pathology; D011379:Prognosis; D015203:Reproducibility of Results; D012720:Severity of Illness Index