[805] The Status of Positive Surgical Margin at Radical Prostatectomy and Risk of Biochemical Recurrence: A Single Institution Experience

M Li, J Song, S Shikanov, S Eggnener, A Shalhav, J Taxy, H Al-Ahmadie. University of Chicago, Chicago

Background: After radical prostatectomy (RP), a positive surgical margin (PSM) is one factor that conveys an increased risk of biochemical recurrence (BCR). Higher risk may be associated with increased length of PSM. Stratifying PSM according to the relative risk of post RP recurrence may determine the potential benefit from adjuvant therapy after RP. Here we analyzed a large cohort of RP patients with PSM to determine risk factors associated with BCR.
Design: All RP cases from 2005 to 2008 at our institution were selected. PSM was defined as the presence of tumor cells at the inked margin. Specimens were assessed for the number, location and length of foci of PSM. For cases with multiple PSM foci, the total length was used in analysis. BCR was defined as a rise in the serum PSA level of 0.05 ng/mL. Follow-up data was obtained from a prospectively maintained database.
Results: Of 1398 RP, 243 (17%) had PSM, 25% with multiple foci. The location of PSM was most often posterolateral (45%) followed by apical (29%), bladder neck (6%) and anterior (2%). BCR was significantly higher in patients with PSM than those without PSM (11% vs 3%, p < 0.0001); and the median of BCR-free intervals was significantly shorter (8 vs 12 months, p = 0.01). The length of PSM was <1 mm in 44%, 1-3 mm in 33% and >3 mm in 23% of the cases. The difference in BCR-free survival of these groups during the follow-up was statistically significant (91%, 84%, and 60%, respectively, P<0.05, Fig. 1). The location and number of PSM foci did not correlate with BCR. By multivariate analysis, a PSM length of >3 mm, a Gleason score of 8 and tumor stage were independent predictors of BCR.


Conclusions: The length of PSM is a significant and independent prognostic factor for BCR in patients following RP, but not the number of PSM foci or their location. Including the length of PSM may help to stratify patients' risk of BCR after RP. Longer follow-up could further define the exact effect of PSM on the long-term oncologic outcome after RP.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 126, Monday Morning