[805] Tumor Gleason Grade and the Extent of Involvement at the Margin in Radical Prostatectomy Are Predictive of Prostate Cancer Recurrence

D Cao, AS Kibel, F Gao, PA Humphrey. Washington University School of Medicine, Saint Louis

Background: Radical prostatectomy (RP) is an effective method to treat prostate cancer. Many pathologic factors inlcuding positive margins have been identified as useful parameters to predict tumor recurrence. However, no study has assessed whether the tumor Gleason grade at the margin is predicitive of recurrence.
Design: 384 RPs (1989-2008) with at least one positive margin (bladder neck, distal apex, and peripheral), followup information, and available slides were retrieved. The following information was documented: age, tumor location (apex, base), Gleason grade of the main tumor and of the tumor at each positive margin, extraprostatic extension (focal, extensive), stage, positive margin location, and the extent of tumor involvement (ETI) at the margin (defined as tumor at the ink, measured with a micrometer as the aggregates in mm, bladder neck not measured). Prostate-specific antigen (PSA) recurence is defined as a serum PSA > 0.2 ng/ml after RP.
Results: The mean age of patients at the time of diagnosis were 61.2 years (38.8 to 80.3 years). The patients were followed for a mean of 46.1 months (range 0.7 to 232.4 months). There were total 446 positive margins in 384 cases: 327 cases with only 1 positive margin, 52 with 2 positive margins, and 5 with three positive margins. 56/384 (14.6%) had a positive bladder neck(BN), 154/384 (40.1%) had a positive distal apical margin, and 246/384 (64.15%) had a positive peripheral margin. The Gleason grade distribution of the main tumor and the tumor at the positive margins were in table 1 (13 cases were treated or margin significantly cauterized not listed).

Gleason grade correlation between main tumor and at the margin
Gleason grade in main tumorHighest Gleason grade at the margins
678910
6742000
8157961010
814601
913663
Total2331052274


The Gleason grade (higher or highest grade if more than 1 positive margin) of the tumor at the margin was the higher than that in the main tumor in 17 (4.5%), similar in 180 (48.6%), and lower in 174 (47%) cases. The mean ETI at the margin is 3.84 mm (0.1 to 42 mm). The Gleason grade at the margin (all cases) and the ETI (excluding BN+ cases) were strongly associated with PSA recurrence (p < 0.05 for both).
Conclusions: In only a small percentage (5%) of RPs, the tumor at the positive margin (s) demonstrated a higher Gleason grade than that of the main tumor. The tumor Gleason grade and the ETI at the margin were predictive of PSA recurrence.
Category: Genitourinary (including renal tumors)

Monday, March 22, 2010 1:00 PM

Poster Session II # 122, Monday Afternoon

 

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