title: Number of positive preoperative biopsy cores is a predictor of positive surgical margins (PSM) in small prostates after robot-assisted radical prostatectomy (RARP).
abstract: OBJECTIVE
  To determine the impact of prostate size on positive surgical margin (PSM) rates after robot-assisted radical prostatectomy (RARP) and the preoperative factors associated with PSM.
  
  
  METHODS
  In all, 1229 men underwent RARP by a single surgeon, from 2005 to August of 2013. Excluded were patients who had transurethral resection of the prostate, neoadjuvant therapy, clinically advanced cancer, and the first 200 performed cases (to reduce the effect of learning curve). Included were 815 patients who were then divided into three prostate size groups: <31 g (group 1), 31-45 g (group 2), >45 g (group 3). Multivariate analysis determined predictors of PSM and biochemical recurrence (BCR).
  
  
  RESULTS
  Console time and blood loss increased with increasing prostate size. There were more high-grade tumours in group 1 (group 1 vs group 2 and group 3, 33.9% vs 25.1% and 25.6%, P = 0.003 and P = 0.005). PSM rates were higher in prostates of <45 g with preoperative PSA levels of >20 ng/dL, Gleason score ≥7, T3 tumour, and ≥3 positive biopsy cores. In group 1, preoperative stage T3 [odds ratio (OR) 3.94, P = 0.020] and ≥3 positive biopsy cores (OR 2.52, P = 0.043) were predictive of PSM, while a PSA level of >20 ng/dL predicted the occurrence of BCR (OR 5.34, P = 0.021). No preoperative factors predicted PSM or BCR for groups 2 and 3.
  
  
  CONCLUSIONS
  A preoperative biopsy with ≥3 positive cores in men with small prostates predicts PSM after RARP. In small prostates with PSM, a PSA level of >20 ng/dL is a predictor of BCR. These factors should guide the choice of therapy and indicate the need for closer postoperative follow-up.
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Tuliao
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyo C
authors.initials: KC
authors.lastname: Koo
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Christos
authors.initials: C
authors.lastname: Komninos
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chien H
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young D
authors.initials: YD
authors.lastname: Choi
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Byung H
authors.initials: BH
authors.lastname: Chung
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung J
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Koon H
authors.initials: KH
authors.lastname: Rha
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011467:Prostate / Q000473:pathology* / Q000502:physiology; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D065287:Robotic Surgical Procedures / Q000379:methods*
keywords: prostate; prostatectomy; prostatic neoplasms; surgical margins