[800] Validation of the Contemporary Epstein Criteria for Insignificant Prostate Cancer in South-American Men

Athanase Billis, Luciana Meirelles, Leandro LLL Freitas, Arthur A Tavares, Flavia F Carvalho, Joao PU Fontenele, Luiz GF Cortes. University of Campinas (Unicamp) School of Medicine, Campinas, SP, Brazil

Background: Due to widespread of PSA screening an increasing number of T1c prostate carcinomas are diagnosed as well as the so-called clinically insignificant tumors. The latter, in turn, may increase potentially unnecessary treatment. Epstein's criteria for prediction of clinically insignificant cancer on needle biopsies are widely used, however, there are discrepancies in the validation according to the country. In the United States (Johns Hopkins), Europe (Germany), Asia (South Korea), and Middle West (Egypt), the prediction rate is 84%, 76%, 69%, and 54%, respectively. This is the first validation from a South-American country (Brazil).
Design: The study was based on patients submitted to radical retropubic prostatectomy which needle prostatic biopsies met Epstein's criteria: stage T1c, PSA density <0.15, Gleason score ≤6, fewer than 3 biopsies with prostate cancer, and no more than 50% of cancer involvement in any core. The mean, median, minimum and maximum number of cores on biopsy was 11, 12, 6 and 20 cores, respectively. Each core was embedded separately and submitted in multiple containers. PSA density was calculated by dividing the absolute PSA value by the prostatic weight, which was defined as the weight of the surgical specimen minus the weight of the seminal vesicles. All biopsies and radical prostatectomies were checked by a senior uropathologist. Tumor extent in surgical specimen was evaluated by a semiquantitative point-count method.
Results: From a total of 400 patients submitted to radical retropubic prostatectomy, 169/400 (42.3%) had T1c prostate cancer. From 169 biopsies in stage T1c, 18/169 (10.7%) met Epstein's criteria for insignificant cancer. On radical prostatectomy, from these 18 cases, 17/18 (94.4%) were confined to the prostate; 13/18 (72.2%) were confined to the prostate with Gleason score ≤6, and with any tumor extent; and, 11/18 (61.1%) were confined to the prostate with Gleason score ≤6, and with limited extent.
Conclusions: The rate of prediction of clinically insignificant cancer on needle biopsies in our study was between that from Europe (Germany) and Asia (South Korea) and much higher than from Middle East (Egypt). The rate of prediction was lower when considering insignificant cancer confined to the prostate, with Gleason score ≤6, and with limited extent. The wide differences among countries may be related to innate differences associated with racial, alimentary, enviromental, and particularly to the sample of the needle prostate biopsy.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 117, Wednesday Morning

 

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