title: Identifying appropriate patients for early salvage radiotherapy after prostatectomy.
abstract: OBJECTIVE
  It remains unclear whether relapsed prostate specific antigen at postprostatectomy salvage radiotherapy impacts outcomes as long it is 1.0 ng/ml or less.
  
  
  METHODS
  We performed a retrospective cohort study of 197 patients treated with salvage radiotherapy in the setting of detectable relapsed prostate specific antigen 1.0 ng/ml or less. Patients were excluded from analysis if they had lymph node involvement or received androgen deprivation therapy. Freedom from prostate specific antigen progression after salvage radiotherapy was analyzed by a Cox regression model.
  
  
  RESULTS
  Median relapsed prostate specific antigen was 0.33 ng/ml (range 0.07 to 1.0). There was 86% freedom from prostate specific antigen progression at a median followup of 52 months. Relapsed prostate specific antigen (HR 1.9, p = 0.004), Gleason score 8-10 (HR 5.2, p <0.001) and negative margin status (HR 2.0, p = 0.02) were independently associated with an increased risk of prostate specific antigen progression after salvage radiotherapy. We identified interaction between relapsed prostate specific antigen and Gleason score (p = 0.04) but not margin status. A significant association was noted between higher relapsed prostate specific antigen and prostate specific antigen progression after salvage radiotherapy in patients with Gleason score 8-10 but not 7 or less. In patients with Gleason score 8-10 the rate of freedom from prostate specific antigen progression at 53 months was 77% vs 26% when salvage radiotherapy was initiated at a relapsed prostate specific antigen of 0.33 or less vs 0.34 to 1.0 ng/ml (log rank p = 0.003).
  
  
  CONCLUSIONS
  Different relapsed prostate specific antigen thresholds for unsuccessful salvage radiotherapy may exist based on Gleason score. These data suggest that patients with Gleason score 8-10 should be offered salvage radiotherapy at the earliest detectable relapsed prostate specific antigen, even 0.33 ng/ml or less. Those with Gleason score 7 or less may have the opportunity to be followed with serial prostate specific antigen measurements to improve risk stratification, and delay and/or avoid the potential toxicity of salvage radiotherapy.
authors: Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia.
authors: Jeremy D
authors: JD
authors: Karlin
authors: Bridget F
authors: BF
authors: Koontz
authors: Stephen J
authors: SJ
authors: Freedland
authors: Judd W
authors: JW
authors: Moul
authors: Baruch M
authors: BM
authors: Grob
authors: Wen
authors: W
authors: Wan
authors: Michael P
authors: MP
authors: Hagan
authors: Mitchell S
authors: MS
authors: Anscher
authors: Drew
authors: D
authors: Moghanaki
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000532:radiotherapy*; D018579:Patient Selection; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000532:radiotherapy* / Q000601:surgery*; D012189:Retrospective Studies; D016879:Salvage Therapy; D013997:Time Factors
chemical_list: D017430:Prostate-Specific Antigen
keywords: FFPP; GS; Gleason score; PSA; SRT; SVI; freedom from PSA progression; prostate; prostate specific antigen; prostate-specific antigen; prostatic neoplasms; rPSA; radiotherapy; relapsed PSA; salvage radiation therapy; salvage therapy; seminal vesicle invasion