title: Does prostate-specific antigen nadir predict longer-term outcomes of prostate cancer after neoadjuvant and adjuvant androgen deprivation therapy in conjunction with brachytherapy?
abstract: OBJECTIVE
  To evaluate whether nadir prostate-specific antigen (nPSA), time to nPSA (TnPSA), and nPSA 3-years post-treatment are prognostic for prostate cancer (PC) in patients treated with temporary brachytherapy plus external beam radiation therapy (EBRT) and hormonal manipulation.
  
  
  METHODS
  We retrospectively analyzed our database of 253 patients with Stage T1-T3 N0M0 PC who underwent brachytherapy with temporary brachytherapy plus EBRT. All patients received neoadjuvant androgen deprivation for a median of 6 months. Treatment consisted of three pulses of pseudo pulsed-dose-rate brachytherapy to a median dose of 18Gy with 50.4Gy in 28 fractions of EBRT. Treatment took place between December 1999 and March 2006.
  
  
  RESULTS
  At a median of 6-years followup, nPSA value was a predictor of biochemical control. Rising nPSA categories of <0.01, 0.01-<0.05, 0.05-≤0.1, 0.1-≤ 1.0, or >1.0 ng/mL correlated with a deteriorating 5-year biochemical control (nBED) by the Phoenix definition of 100%, 90.0%, 82.5%, 64.3%, and 10%, respectively. A highly statistically significant relationship between nPSA value and subsequent clinical failure is also demonstrated. The relationship between TnPSA and nBED was strongly significant (p<0.0001), with a significantly longer nPSA for patients who had Phoenix nBED. A PSA of <1.5 ng/mL achieved 3-year post radiation therapy was prognostic for biochemical and clinical disease control (p<0.0001).
  
  
  CONCLUSIONS
  The nPSA, TnPSA, and reaching a PSA cutoff level of <1.5 ng/mL at 3 years post-treatment can provide useful prognostic information on long-term biochemical and clinical control of PC in patients treated with pseudo PDR, EBRT, and hormone manipulation.
authors.affiliation: Crown Princess Mary Cancer Centre, Westmead Hospital, Sydney, Australia. Electronic address: lucindamorris@hotmail.com.
authors.forename: Lucinda May
authors.initials: LM
authors.lastname: Morris
authors.affiliation: Department of Radiotherapy, Mater Hospital, North Sydney, New South Wales, Australia.
authors.forename: Michael Anthony
authors.initials: MA
authors.lastname: Izard
authors.affiliation: Department of Biostatistics, University of Sydney, New South Wales, Australia.
authors.forename: Wai-Yin
authors.initials: WY
authors.lastname: Wan
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000532:radiotherapy / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D001918:Brachytherapy / Q000379:methods; D017024:Chemotherapy, Adjuvant; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000532:radiotherapy / Q000628:therapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies
chemical_list: D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen
keywords: Brachytherapy; HDR; High-dose-rate; PDR; PSA nadir; Prostate specific antigen nadir; Prostatic neoplasm; Pulsed dose rate; Time to PSA nadir