title: Interobserver agreement of Gleason score and modified Gleason score in needle biopsy and in surgical specimen of prostate cancer.
abstract: BACKGROUND
  Gleason score, which has a high interobserver variability, is used to classify prostate cancer. The most recent consensus valued the tertiary Gleason pattern and recommended its use in the final score of needle biopsies (modified Gleason score). This pattern is considered to be of high prognostic value in surgical specimens. This study emphasized the evaluation of the modified score agreement in needle biopsies and in surgical specimen, as well as the interobserver variability of this score.
  
  
  METHODS
  Three pathologists evaluated the slides of needle biopsies and surgical specimens of 110 patients, reporting primary, secondary and tertiary Gleason patterns and after that, traditional and modified Gleason scores were calculated. Kappa test (K) assessed the interobserver agreement and the agreement between the traditional and modified scores of the biopsy and of the surgical specimen.
  
  
  RESULTS
  Interobserver agreement in the biopsy was K = 0.36 and K = 0.35, and in the surgical specimen it was K = 0.46 and K = 0.36, for the traditional and modified scores, respectively. The tertiary Gleason grade was found in 8%, 0% and 2% of the biopsies and in 8%, 0% and 13% of the surgical specimens, according to observers 1, 2 and 3, respectively. When evaluating the agreement of the traditional and modified Gleason scores in needle biopsy with both scores of the surgical specimen, a similar agreement was found through Kappa.
  
  
  CONCLUSIONS
  Contrary to what was expected, the modified Gleason score was not superior in the agreement between the biopsy score and the specimen, or in interobserver reproducibility, in this study.
authors.affiliation: Section of Urology, Mario Penna Hospital, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. velososg@ig.com.br
authors.forename: Sergio G
authors.initials: SG
authors.lastname: Veloso
authors.forename: Mario F
authors.initials: MF
authors.lastname: Lima
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Salles
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Berenstein
authors.forename: Joao D
authors.initials: JD
authors.lastname: Scalon
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Bambirra
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods* / Q000706:statistics & numerical data; D015588:Observer Variation; D011467:Prostate / Q000473:pathology*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000145:classification / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results