title: Prostate specific antigen: a prognostic marker of survival in good prognosis metastatic prostate cancer? (EORTC 30892).
abstract: OBJECTIVE
  We study the value of PSA response and PSA progression as prognostic factors for survival in good prognosis metastatic prostate cancer.
  
  
  METHODS
  Data from 257 patients treated with Flutamide or Cyproterone acetate within the EORTC GU Group protocol 30892 have been used and analysis by Cox models.
  
  
  RESULTS
  A PSA response defined as a decrease to < or = 1 ng/ml and to between 1 and 10 ng/ml was associated with a hazard ratio of 0.30 and 0.61 for overall survival, respectively, as compared to the non-responders (PSA> 10 ng/ml). Five definitions of PSA progression were considered: (1) a confirmed or (2) a repeated doubling of the PSA over nadir and unconfirmed (3) 100%, (4) 50% and (5) 20% increase of the PSA over nadir, each to a value > 4 ng/ml. Definition (5) was the most sensitive with sensitivity 76.20% and specificity 32.08%. With this definition, 70.0% of the patients had a PSA progression, which occurred in median 1.98 years before death.
  
  
  CONCLUSIONS
  For good prognosis metastatic prostate cancer patients under anti-androgen treatment, PSA response at 6 months with cut-off levels of < or = 1 ng/ml and < or = 10 ng/ml is prognostic for survival. A 20% increase over nadir to a value > 4 ng/ml is prognostic for a poor survival with a 76.20% sensitivity. In this study, confirmation of the increase by a second observation did not seem necessary. Genuine surrogacy is not established in this study.
authors.affiliation: EORTC Data Center, Rue E. Mounier 83, B.11, B-1200 Brussels, Belgium. lco@eortc.be
authors.forename: Laurence
authors.initials: L
authors.lastname: Collette
authors.forename: Theo M
authors.initials: TM
authors.lastname: de Reijke
authors.forename: Fritz H
authors.initials: FH
authors.lastname: Schröder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood*; D001859:Bone Neoplasms / Q000556:secondary*; D017373:Cyproterone Acetate / Q000627:therapeutic use; D018450:Disease Progression; D005485:Flutamide / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality; D012680:Sensitivity and Specificity; D012983:Soft Tissue Neoplasms / Q000556:secondary*; D016019:Survival Analysis
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D017373:Cyproterone Acetate; D005485:Flutamide; D017430:Prostate-Specific Antigen