title: Prediction of biochemical recurrence after robot-assisted radical prostatectomy: analysis of 784 Japanese patients.
abstract: OBJECTIVE
  To examine biochemical recurrence after robot-assisted radical prostatectomy in Japanese patients, and to develop a risk stratification model for biochemical recurrence.
  
  
  METHODS
  The study cohort consisted of 784 patients with localized prostate cancer who underwent robot-assisted radical prostatectomy without neoadjuvant or adjuvant endocrine therapy. The relationships of biochemical recurrence with perioperative findings were evaluated. The prognostic factors for biochemical recurrence-free survival were evaluated using Cox proportional hazard model analyses.
  
  
  RESULTS
  During the follow-up period, 80 patients showed biochemical recurrence. The biochemical recurrence-free survival rates at 1, 3, and 5 years were 92.2%, 85.2% and 80.1%, respectively. In univariate analysis, the prostate-specific antigen level, prostate-specific antigen density, biopsy Gleason score, percent positive core, pathological T stage, pathological Gleason score, lymphovascular invasion, perineural invasion and positive surgical margin were significantly associated with biochemical recurrence. In multivariate analysis, prostate-specific antigen density ≥0.4 (P = 0.0011), pathological T stage ≥3a (P = 0.002), pathological Gleason score ≥8 (P = 0.007) and positive surgical margin (P < 0.0001) were independent predictors of biochemical recurrence. The patients were stratified into three risk groups according to these factors. The 5-year biochemical recurrence-free survival rate was 89.4% in the low-risk group, 65.6% in the intermediate-risk group and 30.3% in the high-risk group.
  
  
  CONCLUSIONS
  The prostate-specific antigen density, pathological T stage, pathological Gleason score and positive surgical margin were independent prognostic factors for biochemical recurrence. The risk stratification model developed using these four factors could help clinicians identify patients with a poor prognosis who might be good candidates for clinical trials of alternative management strategies.
authors.affiliation: Department of Urology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Yoshioka
authors.forename: Go
authors.initials: G
authors.lastname: Nagao
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nakagami
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ohno
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Horiguchi
authors.forename: Kazunori
authors.initials: K
authors.lastname: Namiki
authors.forename: Jun
authors.initials: J
authors.lastname: Nakashima
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tachibana
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism*; D011379:Prognosis; D011467:Prostate / Q000473:pathology* / Q000601:surgery; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D012371:Robotics; D015996:Survival Rate / Q000639:trends
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
keywords: biochemical recurrence; pathological Gleason score; pathological T stage; positive surgical margin; prostate-specific antigen density