title: Concordance between biopsy and radical prostatectomy specimen Gleason score in internal and external pathology facilities.
abstract: BACKGROUND
  Biopsy Gleason score (bGS) is an important tool for staging and decision making in patients with prostate cancer. Therefore, the data from biopsy should be both reproducible across different pathologists and predictive of the true underlying tumour. We evaluated the agreement between bGS with prostatectomy Gleason score (pGS) comparing patients who underwent prostate biopsy at our hospital with those who did it at an outside facility.
  
  
  METHODS
  We retrospectively analyzed patients who underwent robot-assisted radical prostatectomy at our Hospital in 2011 and 2012. Patients were divided depending on the site of prostate biopsy. We calculated a weighted κ statistic to evaluate the concordance from bGS and pGS in the two groups and to evaluate the Gleason score (GS) concordance comparing the proportion of positive cores at biopsy.
  
  
  RESULTS
  A total of 124 patients with completed data were identified (70 patients performed biopsy at our institution and 54 at an outside facility). The weighted κ score for GS agreement was 0.40 for our Institution and 0.27 for other facilities. The weighted κ score stratified by biopsy hospital for patients with at least 30% of positive cores was 0.46 for our hospital and 0.42 for other facilities.
  
  
  CONCLUSIONS
  Internal prostate biopsy predicted better pGS than outside facility biopsy reports. When the percentage of biopsy-positive cores increases, the agreement between bGS and pGS is similar between the two groups. For certain cases in which an outside laboratory biopsy results in equivocal clinical decision, biopsy re-evaluation by internal pathologists can help reveal the true underlying tumor architecture and extension.
authors.affiliation: Urology Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy angelica_grasso@yahoo.it.
authors.forename: Angelica A C
authors.initials: AA
authors.lastname: Grasso
authors.affiliation: Urology Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Cozzi
authors.affiliation: Urology Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Palumbo
authors.affiliation: Urology Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Albo
authors.affiliation: Urology Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Rocco
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Gleason score; prostate cancer; radical prostatectomy