[994] Positive Margins in pT2 Prostate Cancer in Open, Laparoscopic and Robot-Assisted Radical Prostatectomy Specimens

P Troncoso, S Matin, RJ Babaian, CA Pettaway, LL Pisters, I Prokhorova, JW Davis. The University of Texas MD Anderson Cancer Center, Houston, TX

Background: Open radical retropubic prostatectomy (ORP) is the gold standard surgical treatment for clinically localized prostate cancer. While a small number of centers introduced the laparoscopic technique (LRP), a much larger number have moved on to robotic-assisted technique (RARP). Comparison of the positive margin (+MOR) rates in pT2 cases is a useful surrogate for oncologic safety when new technologies are introduced into clinical practice.
Design: We selected from our contemporary series patients with pT2, NX/N0 disease and a +MOR, treated by either open radical prostatectomy (2002-07), LRP (2002-06) or RARP (2006-09). Patients who received neoadjuvant treatment were excluded. These three groups were compared for the incidence, extent, and location of the observed +MOR.
Results: There were 152 pT2 cases with +MOR, including 95 ORP (95/1162, 8%), 22 LRP (22/193, 11%) and 35 RARP (35/588, 6%) The majority of the patients were white (76%) and the clinical stage was T1c in 64% of the patients. The median PSA was 5.30 ng/ml. The median Gleason score was 7(3+4). Tumor was multifocal in 91% of the cases with a median number of three cancer foci per specimen. The median total tumor volume was 1.58 cc. A +MOR involved a single location in 87% of the cases (83% ORP; 91% LRP; 97% RARP). The most common locations for a single +MOR were the apex (44% ORP; 80% LRP; 44% RARP), posterolateral surface (27% ORP; 10% LRP; 26% RARP) and the bladder neck (15% ORP; 10% LRP ; 21% RARP). In cases with more than one +MOR location, the apex was included in 68% (13/19) of the cases. The extent of the +MOR was <1.0 mm in over one third of the cases (34% ORP; 32% LRP; 46% RARP). The mean +MOR extent for cases with a +MOR ≥1 was 5.19 mm (5.04 ORP; 6.97 LRP; 4.32 RARP). The dominant tumor focus involved the MOR in cases with single or multiple +MOR locations in 81% of the cases, including dominant foci of transition zone origin in 38% of the cases.
Conclusions: The data in this study suggest that the introduction of the novel laparoscopic technique resulted in an increase in pT2 positive margin cases relative to open surgery at a high volume center, whereas with the robotic technique, the trend was favorable. The location of positive margins was identical with open and robotic techniques.
Category: Genitourinary (including renal tumors)

Monday, March 22, 2010 1:00 PM

Poster Session II # 120, Monday Afternoon

 

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