title: The proportion of prostate biopsy tissue with Gleason pattern 4 or 5 predicts for biochemical and clinical outcome after radiotherapy for prostate cancer.
abstract: OBJECTIVE
  To investigate the prognostic utility of the proportion of prostate biopsy tissue containing Gleason pattern 4 or 5 (GP4/5) after definitive radiotherapy (RT) for prostate cancer.
  
  
  METHODS
  A total of 568 patients with T1c-3 Nx/0 prostate cancer who received three-dimensional conformal RT alone between May 1989 and August 2001 were studied. There were 161 men with Gleason score 7-10 disease. The GP4/5 was defined as the percentage of biopsy tissue containing Gleason pattern 4 or 5. A Cox proportional hazards model was used for univariate and multivariate analyses (MVA) for biochemical failure (BF) (American Society of Therapeutic Radiology and Oncology definition) and distant metastasis (DM). A recursive partitioning analysis was done using the results of the MVA to identify a cutpoint for GP4/5.
  
  
  RESULTS
  The median follow-up was 46 (range, 13-114) months and median RT dose was 76 (range, 65-82) Gy. On MVA, increasing initial prostate-specific antigen (p = 0.0248) decreasing RT dose (continuous, p = 0.0022), T stage (T1/2 vs. T3), (p = 0.0136) and GP4/5 (continuous, p < 0.0001) were significant predictors of BF in a model also containing GS. GP4/5 was the only significant predictor of DM in the same model (p < 0.0001).
  
  
  CONCLUSIONS
  The GP4/5 in prostate biopsy specimens is a predictor of BF and DM after RT independent of Gleason score. This parameter should be reported by the pathologist when reviewing prostatic biopsy specimens.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: D'Ambrosio
authors.forename: Alexandra L
authors.initials: AL
authors.lastname: Hanlon
authors.forename: Tahseen
authors.initials: T
authors.lastname: Al-Saleem
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Feigenberg
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horwitz
authors.forename: Robert G
authors.initials: RG
authors.lastname: Uzzo
authors.forename: Alan
authors.initials: A
authors.lastname: Pollack
authors.forename: Mark K
authors.initials: MK
authors.lastname: Buyyounouski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology* / Q000532:radiotherapy; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen