title: Prognostic impact of time to undetectable prostate-specific antigen in patients with positive surgical margins following radical prostatectomy.
abstract: BACKGROUND
  The purpose of this article was to determine the impact of time to undetectable prostate-specific antigen (PSA) for predicting biochemical recurrence (BCR) in patients with a positive surgical margin (PSM) following radical prostatectomy (RP). A PSM is an independent predictor of BCR; however, not all patients develop BCR later on.
  
  
  METHODS
  A retrospective analysis was conducted on 1,117 consecutive prostate cancer patients who underwent RP without neoadjuvant or adjuvant therapy from July 2005 to December 2009. Of these, 516 (46.2 %) patients without PSMs, and 214 (19.2 %) patients with PSMs who later achieved undetectable PSA, defined as <0.01 ng/ml, were identified. Patients with PSMs were stratified according to time to undetectable PSA dichotomized at 6 weeks and compared with patients without PSMs. Patients with PSMs who did not achieve undetectable PSA were excluded. BCR was defined as two consecutive increases of post-undetectable PSA ≥0.2 ng/ml.
  
  
  RESULTS
  During the median follow-up of 58.2 months, patients with PSMs who achieved undetectable PSA in <6 weeks had comparable 5-year BCR-free survival rates to those without PSMs; however, patients with PSMs who achieved undetectable PSA in ≥6 weeks showed significantly lower rates compared with both patients without PSMs (59.2 vs 74.3 %; p < 0.001) and patients with PSMs who achieved undetectable PSA in <6 weeks (59.2 vs 78.8 %; p = 0.004). Among patients with PSMs, multivariate analysis revealed time to undetectable PSA at ≥6 weeks and seminal vesicle invasion to be independent predictors of BCR. No perioperative factors were associated with undetectable PSA at ≥6 weeks.
  
  
  CONCLUSIONS
  Patients with PSMs who achieve undetectable PSA in <6 weeks show comparable risks of BCR to patients with negative surgical margins.
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyo Chul
authors.initials: KC
authors.lastname: Koo
authors.forename: Patrick
authors.initials: P
authors.lastname: Tuliao
authors.forename: Christos
authors.initials: C
authors.lastname: Komninos
authors.forename: Young Deuk
authors.initials: YD
authors.lastname: Choi
authors.forename: Byung Ha
authors.initials: BH
authors.lastname: Chung
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Hong
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Jee
authors.forename: Koon Ho
authors.initials: KH
authors.lastname: Rha
mesh_terms: D000368:Aged; D003131:Combined Modality Therapy; D006801:Humans; D007610:Kallikreins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: C549870:KLK3 protein, human; D007610:Kallikreins; D017430:Prostate-Specific Antigen