The proportion of prostate biopsy tissue with Gleason pattern 4 or 5 predicts for biochemical and clinical outcome after radiotherapy for prostate cancer.
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.
D'Ambrosio
David J
DJ
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
Hanlon
Alexandra L
AL
Al-Saleem
Tahseen
T
Feigenberg
Steven J
SJ
Horwitz
Eric M
EM
Uzzo
Robert G
RG
Pollack
Alan
A
Buyyounouski
Mark K
MK
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
D017430:Prostate-Specific Antigen