title: Concordance between transrectal ultrasound guided biopsy results and radical prostatectomy final pathology: Are we getting better at predicting final pathology?
abstract: BACKGROUND
  Inaccuracy in biopsy Gleason scoring poses a risk to men who may then receive inappropriate treatment. We assess whether there was a change in discordance rates between biopsy and radical prostatectomy at our institution in recent years, while considering the implementation of active surveillance and the shift in biopsy scores caused by the 2005 International Society of Urologic Pathology update to the Gleason scoring protocol.
  
  
  METHODS
  We reviewed patients who underwent radical prostatectomy at our institution between May 2004 and April 2011. We analyzed clinical and pathological correlates of upgrading in 3 subgroups: Gleason sum (GS) 6/6, GS6/7 and GS7/7, where the sum preceding the dash was determined from biopsy and the subsequent sum was determined from the radical prostatectomy specimen. We applied the log-rank test and Cox model to a Kaplan Meier analysis of biochemical recurrence in the subgroups, and also mapped GS6/7 discordance over time.
  
  
  RESULTS
  In total, 1717 patients met our inclusion criteria. The 3 subgroups had significantly different mean prostate-specific antigen, patient age, tumour volume, margin status, pathologic stage, prostate weight, transrectal ultrasound volume and rate of progression (p < 0.05). We noted a multiphasic trend with a fall in discordance after 2005. However, there was no sustained trend over the study period taken as a whole (p = 0.06).
  
  
  CONCLUSIONS
  Although no sustained trend was observed, the falling discordance after 2005 may reflect the accommodation to the Gleason scoring update, while the gradual adoption of active surveillance may have led to the otherwise increasing trends. However, our observations may also be spurious biopsy sampling errors.
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Richard
authors.initials: R
authors.lastname: Walker
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Uri
authors.initials: U
authors.lastname: Lindner
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Alyssa
authors.initials: A
authors.lastname: Louis
authors.affiliation: Meridian Software, Toronto, ON;
authors.forename: Robin
authors.initials: R
authors.lastname: Kalnin
authors.affiliation: Applied Statistician, Markham, ON.
authors.forename: Marguerite
authors.initials: M
authors.lastname: Ennis
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Michael
authors.initials: M
authors.lastname: Nesbitt
authors.affiliation: Department of Pathology, University Health Network, Toronto, ON;
authors.forename: Theodorus H
authors.initials: TH
authors.lastname: van der Kwast
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Antonio
authors.initials: A
authors.lastname: Finelli
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Neil E
authors.initials: NE
authors.lastname: Fleshner
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Alexandre R
authors.initials: AR
authors.lastname: Zlotta
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Michael A S
authors.initials: MA
authors.lastname: Jewett
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Robert
authors.initials: R
authors.lastname: Hamilton
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: Girish
authors.initials: G
authors.lastname: Kulkarni
authors.affiliation: Division of Urology, Department of Surgical Oncology, University Health Network, Toronto, ON;
authors.forename: John
authors.initials: J
authors.lastname: Trachtenberg