[785] Relation of Primary Gleason Pattern 3 or 4 in Prostate Needle Biopsy to Pathological Stage and Progression after Radical Prostatectomy

Ali Amin, Jonathan I Epstein. The Johns Hopkins Hospital, Baltimore

Background: It is still controversial if Gleason score 4+3=7 on prostate biopsy has a worse prognosis than 3+4=7 in predicting pathological stage and biochemical recurrence, especially if the number of positive cores is accounted for. Older studies predated the modified Gleason grading system established in 2005.
Design: In order to determine whether the breakdown of Gleason score 7 into 3+4 vs. 4+3 has prognostic significance in the modern era, we retrospectively studied 1791 cases of Gleason score 7 on prostate biopsy with corresponding radical prostatectomy performed at our institution between 2004-2010. 99.6% of radical prostatectomy specimens were serially sectioned and submitted in entirety; in prostates >80 gms, the entire peripheral zone was submitted with representative sections of the anterior region involved by nodular hyperplasia.
Results: Of total 1791 patients, 1267 cases (70.7%) had a Gleason score 3+4=7 on biopsy, compared to 524 cases (29.2%) that showed biopsy Gleason score 4+3=7.There was no difference in age, preoperative serum PSA level, maximum tumor percentage per core, or the number of positive cores between Gleason score 3+4=7 and Gleason score 4+3=7 on biopsy. Gleason score 4+3=7 on biopsy showed an overall correlation with increasing pathological stage (organ confined, focal extraprostatic extension (EPE), non focal EPE, seminal vesicle invasion/lymph node metastases) (p=0.005). In multivariate analysis, biopsy Gleason score 4+3=7 (p=0.03), number of positive cores (p=0.002), maximum percent of cancer per core (p=0.006) and preoperative serum PSA (p=0.03) all correlated with pathological stage. There was also a higher risk of positive margins at radical prostatectomy with biopsy Gleason score 4+3=7 [120/524 (22.9%)] compared to biopsy 3+4=7 [231/1263 (18.3%)], p=0.03. Biopsy Gleason score 4+3=7 was also associated with an increased risk of biochemical progression after radical prostatectomy (p=0.0001). In multivariate analysis, biopsy Gleason score 4+3=7 (p=0.001), maximum percent of cancer per core (p<0.0001) and preoperative serum PSA (p<0.0001), yet not the number of positive cores correlated with risk of biochemical progression after radical prostatectomy.
Conclusions: Our study further demonstrates that Gleason score 7 should not be considered as a homogeneous group for the purpose of patient management and prognosis, and the dominant Gleason pattern 3 or 4 should be taken into account in reporting Gleason score 7 in biopsy material.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 2:15 PM

Platform Session: Section A, Monday Afternoon

 

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