title: Usefulness of the nadir value of serum prostate-specific antigen measured by an ultrasensitive assay as a predictor of biochemical recurrence after radical prostatectomy for clinically localized prostate cancer.
abstract: BACKGROUND
  The objective of this study was to determine whether the nadir value of serum prostate-specific antigen (PSA) measured by an ultrasensitive assay could be a useful predictor of biochemical recurrence after radical prostatectomy for clinically localized prostate cancer.
  
  
  METHODS
  This study included 127 patients who underwent radical prostatectomy for clinically localized prostate cancer without neoadjuvant hormonal therapy and were pathologically diagnosed as negative for lymph node metastasis. The serum PSA value was measured using an ultrasensitive PSA assay system (Roche Diagnostics, Mannheim, Germany), and the findings were analyzed with respect to several clinicopathological factors. In this series, biochemical recurrence was defined as PSA persistently >0.2 ng/ml.
  
  
  RESULTS
  Based on the nadir PSA value, we divided 127 patients into three groups as follows: group A (n=99):<or=0.01 ng/ml; group B (n=16): 0.01-0.05 ng/ml, and group C (n=12): >or=0.05 ng/ml. The nadir PSA value was significantly associated with preoperative PSA value, but not other conventional clinicopathological prognostic parameters. During the observation period (median 31 months, range 6-75 months), biochemical recurrence occurred in 16 patients, that is, 1 in group A (6.3%), 4 in group B (25.0%), and 11 in group C (91.7%). Multivariate analysis using the Cox proportional hazards regression model indicated that the nadir PSA value was an independent predictor for biochemical recurrence after radical prostatectomy.
  
  
  CONCLUSIONS
  These findings suggest that the nadir serum PSA value measured by an ultrasensitive assay could be a useful predictor of biochemical recurrence after radical prostatectomy for clinically localized prostate cancer, and that careful follow-up should be considered in cases demonstrating a nadir PSA value>0.01 ng/ml because of the significantly higher probability of biochemical recurrence in such cases.
authors.affiliation: Department of Urology, Hyogo Medical Center for Adults, Akashi, and Kobe University School of Medicine, Japan.
authors.forename: Iori
authors.initials: I
authors.lastname: Sakai
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Harada
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Kurahashi
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Muramaki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Yamanaka
authors.forename: Isao
authors.initials: I
authors.lastname: Hara
authors.forename: Taka-aki
authors.initials: TA
authors.lastname: Inoue
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyake
mesh_terms: D000368:Aged; D001774:Blood Chemical Analysis; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000097:blood*; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000601:surgery*; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen