[883] Can Positive Surgical Margins (PSM) and Extraprostatic Extension (EPE) in Robot-Assisted Laparoscopic Radical Prostatectomies (RALP) Be Predicted?

Jennifer M Hawkins, Rebecca C Heintzelman, Jamison Jaffe, Fernando U Garcia. Drexel University College of Medicine, Philadelphia, PA

Background: Since the advent of RALP, the PSM rate has not changed, remaining at 15%. PSM and EPE are independent predictive factors for biochemical recurrence and prostate cancer specific mortality. Despite the importance of PSM and EPE in predicting outcomes, few studies to date have explored the predictive pathologic factors associated with PSM and EPE in RALP. Our objective is to identify clinical and pathologic features to help identify those patients to improve RALP outcomes.
Design: We reviewed retrospectively 285 RALPs performed by 2 surgeons from 2007 to 2011. Prostates were whole mounted, entirely submitted and reviewed by one pathologist. Patient demographics, pre-operative data and pathology report information were reviewed from a Departmental database. This information included: tumor volume, prostate volume, pathologic stage, PSM and EPE and location (apex, base, anterior and posterolateral).
Results: PSM+EPE were present in 13.7% of cases. Average values of clinical and pathological characteristics were analyzed using a t-test. PSM+EPE were seen in the apex 7.7%, base 5.1%, anterior 23.1% and posterolateral 28.3%. Multifocality was present in 17.9%, with discordance in 17.9%. Gleason scores (GS) of ≤6, 7, 8/9 within this subset were 12.8%, 74.4%, 12.8%. Percent core involvement on biopsy correlates with average percent tumor on biopsy, prostatic specific antigen (PSA), GS, prostate volume and tumor volume (p<0.01). Tumor volume, prostate volume and GS were predictive of PSM+EPE using linear regression (p<0.05).

Table 1. Average Clinical and Pathology Characteristics

	Total Cohort (n=285)	PSM+EPE (n=39)	PSM/EPE Negative (n= 196)	P Value
Age	58.26	57.46	58.58	p=0.36
PSA (ng/mL)	6.61	11.54	5.23	p=0.005
% Core Involved	28.67	40.70	23.03	p=0.0001
Avg % Tumor on Biopsy	25.31	35.60	19.49	p=0.0004
Prostate Vol (cc)	35.88	34.45	37.07	p=0.36
Tumor Vol (cc)	2.95	7.28	1.72	p=0.001

Conclusions: 1) 13.7% of post-RALP patients have PSM+EPE, highlighting the need to categorize this population preoperatively. 2) Posterolateral and anterior were the most common and should be evaluated during surgery. 3) Tumor volume, prostate volume and GS are predictive of PSM+EPE in RALP. 4) Percent core involvement on biopsy correlates with the average percent tumor, PSA, GS, prostate and tumor volume and might be a useful feature to identify this population. 5) Additional biopsy information will be studied in a larger cohort to further identify this population.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 163, Monday Morning