[838] Positive Surgical Margins in Otherwise Organ-Confined Disease: Reassessment of Extraprostatic Extension Versus Capsular Incision in 568 Robot-Assisted Laparoscopic Prostatectomies
N Mourtzinos, DE Sutherland, AM Schwartz, FJ Bianco, MK Rezaei. The George Washington University, Washington, DC
Background: Positive surgical margins (PSM) in prostatectomy specimens result from either a capsular incision (CI) into the tumor or extraprostatic extension (EPE). The distinction between the two patterns, although challenging by histology, has significantly different clinical implications. PSM due to CI is related to surgical techniques, whereas EPE denotes the biologic behavior of the tumor. Recently, more attention is being paid to address the difficulties in the histologic assessment of CI versus EPE, focusing on the unique characteristics at different anatomic locations (Chuang and Epstein 2008, Epstein et al 2005).
Design: Between 2004 and 2007, 568 robot-assisted laparoscopic radical prostatectomy procedures were performed at our institution. Two hundred fourteen cases had either EPE, PSM or both. Among this group, seventy-six cases were originally classified as organ-confined disease with PSM at various sites (pT2). PSM was noted at a single site in fifty-five cases and at multiple sites in twenty-one cases. Applying the published revised criteria to identify EPE at various anatomic locations, these cases were re-classified as shown in the table below.
Results: Our results are summarized in Table 1.
| Location | Original PSM - No EPE | Upgraded to PSM @ EPE |
|---|
| Anterior | 1 | 0 | | Anterolateral | 4 | 0 | | Posterior | 3 | 1 | | Posterolateral | 14 | 6 | | Apex | 23 | 10 | | Bladder Neck | 10 | 0 | | Multiple Sites | 21 | 8 |
Applying the revised criteria resulted in upstaging from pT2 to pT3 in 33% (25/76) of our cases. In re-examination of sites with PSM, the upgrades were mostly seen at the posterolateral and apical locations with or without other sites. As shown in the table, five cases of isolated anterior or anterolateral PSM were due to CI. In only one case with multiple sites of PSM, both anterior and anterolateral locations were reclassified as EPE in addition to the posterolateral location.
Conclusions: Our data re-emphasizes that by applying the revised criteria, tailored to specific anatomic locations, EPE will be recognized more effectively, especially in posterolateral and apical locations. As a prognostically significant finding, this will impact clinical staging and patient outcome. Anteriorly and anterolaterally, using the revised criteria did not change the stage, since the presence of tumor in adipose tissue would have likely been originally classified as EPE.
Category: Genitourinary (including renal tumors)
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 131, Tuesday Afternoon
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