[840] Upgrading/Downgrading of Prostate Cancer from Biopsy to Radical Prosatectomy: Incidence and Predictive Factors

Jonathan I Epstein, Bruce Trock, Alex Chang. The Johns Hopkins Hospital, Baltimore

Background: There is the potential for both under and overtreatment if the biopsy (Bx) Gleason Score (GS) does not accurately reflect the radical prostatectomy (RP) GS. The needle biopsy and corresponding RP GS may not be the same for several reasons including: 1) pathology error; 2) borderline cases; and 3) and sampling error.
Design: We analyzed 6,308 totally embedded RP and corresponding Bx (2004-2010), accounting for the updated Gleason system. We excluded cases with RP tertiary higher grade patterns, and only included cases with at least 10 biopsy core sampling.
Results: 26.2% of cases were upgraded from a Bx GS6 to higher grade at RP. Almost 2/3rds of the cases had matching GS 3+4=7 at BX and RP with an approximately equal number of cases downgraded to GS6 or upgraded to GS4+3=7 at RP. When the Bx was 4+3=7, there was an almost equal split between 3+4=7 and 4+3=7 at RP. A Bx of GS8 led to an almost equal distribution between RP GS 4+3=7, 8, and 9-10. Over three-quarters of the cases had matching GS 9-10 at BX and RP. In univariate analysis, clinical stage, serum PSA, RP weight, number of positive cores, and maximum percent of cancer per core all correlated with upgrading and downgrading. Age was predictive only in upgrading. In multivariable analysis, age (p<0.0001), serum PSA level (p<0.0001), RP weight (p<0.0001), and maximum % cancer/core (p<0.0001) predicted upgrade from BX GS6 to higher at RP. Nomograms for predicting upgrading and downgrading were developed to aid clinicians in assessing the likelihood of the accuracy of a biopsy Gleason score.

Biopsy GSRP GS 3+3=6RP GS 3+4=7RP GS 4+3=7RP GS 8RP GS 9-10Total Cases

Conclusions: Higher clinical stage, serum PSA, and extent of cancer on cores correlates with more extensive cancer which correlates to higher grade at RP. It is logical that these variables correlate with a higher risk of upgrading due to sampling error on biopsy. Although not intuitive, our findings are consistent with the literature in showing that smaller prostates are associated with an increased risk of upgrading from biopsy to RP. GS upgrading and downgrading remains an important issue using the updated Gleason system, even when accounting for tertiary Gleason patterns in the RP in entirely submitted RP specimens. More accurate Gleason grading can reduce upgrading, yet in the best of circumstances, approximately one-quarter of GS6 tumors on biopsy will be GS7 or higher at RP.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 119, Wednesday Morning


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