title: Predicting the Gleason sum of a patient with a prostate biopsy core Gleason ≤7 and a prostate biopsy core Gleason ≥8.
abstract: BACKGROUND
  We review a subset of men who had discordant prostate biopsy sums and were treated with radical prostatectomy.
  
  
  METHODS
  Consecutive patients treated with radical prostatectomy at The Ottawa Hospital between 2000 and 2012 were reviewed. Those with at least 1 prostate biopsy core of Gleason sum ≥8 and at least 1 prostate biopsy core of Gleason sum ≤7 cancer were included.
  
  
  RESULTS
  Of the 764 radical prostatectomies, 661 (87%) were eligible for the study and 35 (5%) met inclusion criteria. Of these, only 16 (46%) had prostatectomy Gleason sum of ≥8. When the highest biopsy core was Gleason sum 8 (n = 24), only 7 (29%) had a prostatectomy Gleason sum ≥8. When the highest biopsy core was Gleason 9 (n = 11), 9 (82%) had a prostatectomy Gleason sum ≥8 (relative risk [RR] 2.8; p = 0.004). Patients with clinical T3 tumours were at higher risk of Gleason sum ≥8 compared to cT1 patients (RR 3.7; p = 0.008). Patient age (p = 0.89), preoperative prostate-specific antigen (p = 0.34), prostate volume (p = 0.86), number of biopsy cores (p = 0.18), and proportion of biopsy cores with cancer (p = 0.96) were not strongly associated with risk of prostatectomy Gleason sum ≥8.
  
  
  CONCLUSIONS
  These data should be considered when assigning patients into prognostic risk categories based on prostate biopsy information. Further study to verify our findings using larger samples is warranted.
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Urology, Department of Surgery, McGill University, Montreal, QC;
authors.forename: Olivier P
authors.initials: OP
authors.lastname: Heimrath
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Anatomical Pathology, Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON;
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Kos
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Anatomical Pathology, Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON;
authors.forename: Eric C
authors.initials: EC
authors.lastname: Belanger
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, ON;
authors.forename: Ilias
authors.initials: I
authors.lastname: Cagiannos
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, ON;
authors.forename: Chris
authors.initials: C
authors.lastname: Morash
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, ON;
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Gerridzen
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, ON;
authors.forename: Luke T
authors.initials: LT
authors.lastname: Lavallée
authors.affiliation: Department of Urology, Massachusetts General Hospital, Boston, MA;
authors.forename: Mark A
authors.initials: MA
authors.lastname: Preston
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, ON.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Witiuk
authors.affiliation: University of Ottawa, Ottawa, ON; ; Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, ON; ; Ottawa Hospital Research Institute, Ottawa, ON.
authors.forename: Rodney H
authors.initials: RH
authors.lastname: Breau