[946] Global Gleason Score on Prostate Needle Biopsies as Predictor of Prostatectomy Gleason Score: Comparison with Highest Gleason Score, Greatest-Percent and Largest-Length Gleason Scores.

Maria M Shevchuk, Abhishek Strivastava, Ashutosh Tewari. Weill Cornell Medical College, New York, NY

Background: : According to the literature, the Gleason score on prostate needle biopsies predicts the exact prostatectomy Gleason score in 50-70% of cases, when assessed by genitourinary pathologists. The Gleason score is +/- 1 from the biopsy Gleason score in 85+% of cases. If different Gleason scores are reported on different needle biopsy cores, the urologists usually use the highest Gleason score (hi Gl) to predict the prostatectomy Gleason score and for use in nomograms. The literature also supports the use of the Gleason score of the core with the largest percent of tumor (hi % Gl), or of the core with the longest length of tumor (long Gl). The global Gleason score (gl Gl) reflects the primary and secondary patterns on all of the cores, taken together. We compared all these methods as to their ability to predict the prostatectomy Gleason score.
Design: : Prostate biopsies with different Gleason scores and the subsequent prostatectomies from a single urologist's practice were reviewed by a single uropathologist. A gl Gl, hi Gl, hi % Gl, and long Gl was assigned to each of 44 Gleason-score-discordant cases, and these were compared to the prostatectomy Gleason score.
Results: : The exact Gleason score and the exact component primary and secondary Gleason patterns were identified by gl Gl in 66% of cases, by hi Gl in 61% of cases, by hi % Gl in 50% of cases, and by long Gl in 48% of cases. If only the Gleason scores were compared (without consideration of primary and secondary patterns), the concordance with prostatectomy Gleason score was: 89% for gl Gl; 84% for hi Gl; 68% for hi % Gl; and 66% for long Gl. The difference in predictive value for gl Gl and for hi Gl was not statistically significant, because these two methods identified the identical primary and secondary patterns in 61% of cases, and the same Gleason score in 93% of cases in our series.
Conclusions: Global Gleason score is slightly better, but similar to the hi Gl in predicting prostatectomy Gleason score, and both methods outperform the hi % Gl and long Gl methods. Recording the gl Gl on the biopsy report may give the urologist additional information for therapy choices, in cases such as those with a hi Gl of 4+4 but gl Gl of 4+3, or a hi Gl of 4+5 but gl Gl of 4+3, with tertiary 5.
Category: Genitourinary (including renal tumors)

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 70, Wednesday Morning


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