[814] Long Term Follow-Up (F/U) in Patients with Initial PIN and Benign Prostate Biopsies

Zlatica Biljetina, Jianguo Zhang, Asli Yilmaz, Kiril Trpkov. Calgary Laboratory Services and University of Calgary, Calgary, Canada

Background: There are limited long term F/U data on PCa features on biopsy and RP after initial PIN or benign prostate biopsy.
Design: We identified 161 patients with initial PIN and 85 patients with initial benign prostate biopsies who underwent repeat biopsies in our institution. All patients had extended (10 core, mean) biopsies. We compared the preoperative findings in patients with and without PCa on F/U biopsy and we evaluated the PCa biopsy and radical prostatectomy (RP) findings after initial PIN and benign biopsies. Patients characteristics between the groups were compared using the Wilcoxon rank-sum test for continuous variables and Chi-square test for categorical variables.
Results: We found 43 (26.7%) Pca after PIN and 19 (22.3%) Pca after benign initial biopsy, during a mean F/U of 8.9 and 9.3 years (medians, 11.4 and 11.1 years), respectively. Pca was diagnosed after 1.5 and 2.5 years (p<0.001, mean) after initial PIN vs. benign biopsy, and after 1.9 vs. 1.5 biopsies (NS, mean), respectively. Patients with Pca on F/U in PIN and benign groups differed significantly only in age (63.8 vs. 59.4 years, p=0.032) and PSA Δ (2.7 vs. 3.3 ng/ml; p=0.026). Patients with initial PIN with Pca on F/U vs. no Pca on F/U, were older (63.8 vs. 60.8 years, p=0.039) and had higher PSA (8.6 vs. 6.7 ng/ml; p=0.041), but did not show other significant differences, including the number of PIN biopsy sites. Patients with initial benign biopsy with Pca on F/U vs. no Pca on F/U, had smaller gland volume (45.4 vs. 63.7cc, p=0.012), but had no other significant differences. Pca on F/U biopsy after PIN was 1 or 2 core positive in 96% (mean total Pca 2.4%). 95% Pca biopsies after PIN were Gleason score (GS)6 (84%) or GS3+4 (11%). Of 22 (51%) patients with RP after initial PIN biopsy, 95% had GS6 (86%) or GS3+4 (9%) and all had node negative pT2 disease. Pca on F/U biopsy after initial benign biopsy was 1 or 2 core positive in 79% (mean total Pca 2.3%). 84% of Pca biopsies after initial benign biopsy were GS6 (58%) or GS 3+4 (26%). In 13 (68%) patients who had RP in this group, 85% had GS6 (54%) or GS3+4 (31%) and all had node negative pT2 disease. 91% and 69% of RP showed ≤5% Pca volume after initial PIN and benign biopsy, respectively.
Conclusions: Great majority of patients diagnosed with PCa on extended biopsy after initial PIN or benign biopsy are candidates for active surveillance because they show favourable PCa findings on biopsy and RP on long term F/U. Preoperative findings, including number of PIN sites, did not sufficiently discriminate patients who develop PCa on F/U after initial benign and PIN biopsy.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 185, Tuesday Afternoon

 

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