title: Four prognostic groups predict long-term survival from prostate cancer following radiotherapy alone on Radiation Therapy Oncology Group clinical trials.
abstract: OBJECTIVE
  Gleason score (GS), T stage, and pathologic lymph node status have been described as major independent predictors of death due to prostate cancer in men treated with external beam radiotherapy (XRT). In this analysis we combine these three factors to define prognostic subgroups that correlate with disease-specific survival (DSS) death from prostate cancer.
  
  
  METHODS
  Men entered on one of four Radiation Therapy Oncology Group (RTOG) Phase III randomized trials between 1975 and 1992, for clinically localized prostate cancer (CAP) (n = 1557), were selected for this analysis. Patients were included if: 1) they were evaluable, and eligible for the trial; 2) they received no hormonal therapy with their initial treatment; and 3) follow-up was available. For this study a DSS event was declared if: 1) death was certified as due to CAP; 2) death was due to complications of treatment; or 3) death was from unknown causes with active malignancy. The median follow-up for patients treated on early and late RTOG studies exceeded 11 and 6 years respectively. Subgroups were identified based on their pretreatment GS, T-stage, and lymph node such that patients with similar risk of dying from prostate cancer were combined.
  
  
  RESULTS
  By combining patients with similar DSS, four subgroups were identified. Risk Group 1 patients had a GS = 2-6, and T1-2Nx; Group 2: GS = 2-6, T3Nx; or GS = 2-6, N+, or GS = 7, T1-2Nx; Group 3: T3Nx, GS = 7; or N+, GS = 7, or T1-2Nx, GS = 8-10; and Group 4 patients were T3Nx, GS = 8-10, or N+, GS = 8-10. The 5-, 10-, and 15-year DSS was 96%, 86%, and 72%; 94%, 75%, and 61%; 83%, 62%, and 39%; and 64%, 34%, and 27% for Groups 1 through 4, respectively.
  
  
  CONCLUSIONS
  Recognition of these four risk groups provides a basis for estimating the long-term DSS for men treated with XRT alone and should facilitate the design of future prospective randomized trials.
authors.affiliation: Departments of Radiation Oncology, Medical Oncology, and Urology, University of California San Francisco, San Francisco 94143-0226, USA. roach@radonc17.ucsf.edu
authors.forename: M
authors.initials: M
authors.lastname: Roach
authors.forename: J
authors.initials: J
authors.lastname: Lu
authors.forename: M V
authors.initials: MV
authors.lastname: Pilepich
authors.forename: S O
authors.initials: SO
authors.lastname: Asbell
authors.forename: M
authors.initials: M
authors.lastname: Mohiuddin
authors.forename: R
authors.initials: R
authors.lastname: Terry
authors.forename: D
authors.initials: D
authors.lastname: Grignon
authors.forename: M
authors.initials: M
authors.lastname: Mohuidden
mesh_terms: D000368:Aged; D018572:Disease-Free Survival; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy
chemical_list: D017430:Prostate-Specific Antigen