title: Early PSA level decline is an independent predictor of biochemical and clinical control for salvage postprostatectomy radiotherapy.
abstract: BACKGROUND
  To improve the early detection of responders to salvage external beam radiotherapy (RT) after radical prostatectomy (RP).
  
  
  METHODS
  Between 2002 and 2007, in a single institution, 136 consecutive patients received salvage RT to a dose of 66 Gy without androgen-deprivation therapy after RP for a rising prostate-specific antigen (PSA) level. PSA measurements were systematically performed before RT (PSART), at the fifth week of RT (PSA5), and in the follow-up at least twice a year (every 6 mo). The PSA level decline during RT was expressed as PSA ratio (PSA5/PSART). Two different definitions of biochemical failure after salvage RT were considered: PSA level>0.4 ng/ml and PSA>PSA nadir post-RT +0.4 ng/ml. Statistical analyses included univariate and multivariate Cox regression models.
  
  
  RESULTS
  The median follow-up was 60 months. The 5-year freedom from biochemical and clinical failure rates were 57% (95% CI: 48%-66%) and 92% (95% CI: 87%-97%), respectively. The mean PSA5 was 0.61 ng/ml (range: 0-7) and the mean PSA ratio was 0.67 (0-1.7). A PSA ratio<1 was a significant prognostic factor in multivariate analysis for both definitions of biochemical failure (P = 0.01 for both) and for clinical failure (P = 0.005).
  
  
  CONCLUSIONS
  For patients undergoing salvage RT after RP for a rising PSA level, the absence of PSA level decline during RT is predictive of biochemical and clinical failure and may be used to rapidly identify poor responders.
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Villejuif, France; University Paris Sud, France. Electronic address: pierre.blanchard@gustaveroussy.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Blanchard
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Villejuif, France.
authors.forename: Moudar
authors.initials: M
authors.lastname: Bakkour
authors.affiliation: Department of Radiation Oncology, Centre Eugene Marquis, Rennes, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: De Crevoisier
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Villejuif, France.
authors.forename: Antonin
authors.initials: A
authors.lastname: Levy
authors.affiliation: Department of Urology, Hôpital Saint Joseph, Paris, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Baumert
authors.affiliation: Department of Urology, CHU Kremlin-Bicêtre, Kremlin-Bicêtre, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Patard
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Villejuif, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Wibault
authors.affiliation: Department of Medical Oncology, Institut Gustave Roussy, Villejuif, France; University Paris Sud, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Fizazi
authors.affiliation: Department of Radiation Oncology, Gustave Roussy, Villejuif, France.
authors.forename: Alberto
authors.initials: A
authors.lastname: Bossi
mesh_terms: D000368:Aged; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000532:radiotherapy* / Q000601:surgery; D011878:Radiotherapy; D018714:Radiotherapy, Adjuvant; D016879:Salvage Therapy / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen
keywords: PSA; Prognostic factor; Prostate cancer; Salvage radiotherapy