title: Gleason stratifications prognostic for survival in men receiving definitive external beam radiation therapy for localized prostate cancer.
abstract: OBJECTIVE
  Histologic grade analyses for prostate cancer (PCa) have traditionally included Gleason scores (GS) of ≤6, 7, and 8-10. Stratified biochemical progression-free survival has increasingly been reported within these groups on analyses of primary-secondary patterns (PSPs) (e.g., 3+4 vs. 4+3) and overall GS (e.g., 8 vs. 9 vs. 10) but with limited data regarding stratified survival outcomes. In this analysis, outcomes for biopsy-assigned GS 6 to 10 were comprehensively evaluated to identify stratifications prognostic for survival in patients undergoing external beam radiation therapy (EBRT).
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results database was examined for T1-4 N0 M0, GS 6 to 10 PCa managed with EBRT alone from 2004 to 2006. GS and PSP variations were analyzed for PCa-specific survival (PCSS) and overall survival (OS).
  
  
  RESULTS
  Overall, 26,885 patients were evaluated. Preliminary PSP analyses identified stratifications for 3+4 vs. 4+3 = 7 and 4+4 = 8 vs. GS 8 with pattern 5 (P5) (i.e., 3+5 and 5+3) as significant; however, no differences were observed for 4+5 vs. 5+4 = 9. The primary analysis included stratifications for GS 6, 3+4, 4+3, 4+4, 8 w/P5, 9, and 10, where the 7.5-year PCSS rates were 99%, 97%, 95%, 91%, 86%, 81%, and 78% and 7.5-year OS rates were 83%, 76%, 72%, 67%, 66%, 58%, and 54%, respectively. PCSS differences for sequential score increases were all significant on univariate analyses (all P<0.05). In sequential multivariate analyses of PCSS accounting for age, prostate-specific antigen, T stage, year, marital status, race, and tumor registry, the identified GS stratifications remained significant (all P<0.05), with the exception of GS 8 w/P5 vs. 9 (P = 0.11). In overall multivariate analyses, the identified GS stratifications represented the strongest prognostic factor for survival. Subgroup analyses demonstrated that presence of any P5 was an independent prognostic factor for survival.
  
  
  CONCLUSIONS
  In the largest reported survival analysis of Gleason stratifications, biopsy-assigned GS 6, 3+4, 4+3, 4+4, 8 w/P5, 9, and 10 represented sequential prognostic factors for survival in patients managed with definitive EBRT.
authors.affiliation: Department of Radiation Oncology, University of Colorado-Denver, Aurora, CO. Electronic address: chad.rusthoven@ucdenver.edu.
authors.forename: Chad G
authors.initials: CG
authors.lastname: Rusthoven
authors.affiliation: Department of Radiation Oncology, University of Colorado-Denver, Aurora, CO.
authors.forename: Timothy V
authors.initials: TV
authors.lastname: Waxweiler
authors.affiliation: Department of Biostatistics and Informatics, University of Colorado-Denver, Aurora, CO.
authors.forename: Peter E
authors.initials: PE
authors.lastname: DeWitt
authors.affiliation: Department of Medical Oncology, University of Colorado-Denver, Aurora, CO.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Flaig
authors.affiliation: Department of Radiation Oncology, University of Colorado-Denver, Aurora, CO.
authors.forename: David
authors.initials: D
authors.lastname: Raben
authors.affiliation: Department of Radiation Oncology, University of Colorado-Denver, Aurora, CO.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Kavanagh
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000532:radiotherapy; D018426:SEER Program; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: External beam radiation therapy; Gleason score; Prognosis; Prostate cancer; Survival