title: Comparison of biochemical failure rates between permanent prostate brachytherapy and radical retropubic prostatectomy as a function of posttherapy PSA nadir plus 'X'.
abstract: BACKGROUND
  Prostate-specific antigen (PSA) nadir + 2 ng/mL, also known as the Phoenix definition, is the definition most commonly used to establish biochemical failure (BF) after external beam radiotherapy for prostate cancer management. The purpose of this study is to compare BF rates between permanent prostate brachytherapy (PPB) and radical retropubic prostatectomy (RRP) as a function of PSA nadir plus varying values of X and examine the associated implications.
  
  
  METHODS
  We retrospectively searched for patients who underwent PPB or RRP at our institution between 1998 and 2004. Only primary patients not receiving androgen-deprivation therapy were included in the study. Three RRP patients were matched to each PPB patient on the basis of prognostic factors. BF rates were estimated for PSA nadirs + different values of X.
  
  
  RESULTS
  A total of 1,164 patients were used for analysis: 873 in the RRP group and 291 in the PPB group. Patients were equally matched by clinical stage, biopsy Gleason sum, primary Gleason grade, and pretherapy PSA value. Median follow-up was 3.1 years for RRP patients and 3.6 years in the PPB group (P = .01). Using PSA nadir + 0.1 ng/mL for the definition of BF, the 5-year BF rate was 16.3% for PPB patients and 13.5% for RRP patients (P = .007), whereas at nadir + 2 ng/mL or greater, the BF rates were less than 3% and were indistinguishable between PPB and RRP patients.
  
  
  CONCLUSIONS
  In a cohort of well-matched patients who had prostatectomy or brachytherapy, we examined BF as a function of nadir + X, where X was treated as a continuous variable. As X increases from 0.1 to 2.0 ng/mL, the BF curves converge, and above 2.0 ng/mL they are essentially indistinguishable. The data presented are of interest as BF definitions continue to evolve.
authors: Kamran A
authors: KA
authors: Ahmed
authors: Department of Radiation Oncology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. davis.brian@mayo.edu.
authors: Brian J
authors: BJ
authors: Davis
authors: Lance A
authors: LA
authors: Mynderse
authors: Jeffrey M
authors: JM
authors: Slezak
authors: Eric J
authors: EJ
authors: Bergstralh
authors: Torrence M
authors: TM
authors: Wilson
authors: C Richard
authors: CR
authors: Choo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D001918:Brachytherapy / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy / Q000009:adverse effects*; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D017211:Treatment Failure
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen