[791] Should Pathologists Continue To Use the Current pT2 Substaging System for Reporting of Radical Prostatectomy Specimens?

A Billis, L Meirelles, LLL Freitas, LA Magna, U Ferreira. School of Medicine, University of Campinas (Unicamp), Campinas, Brazil

Background: During the International Society of Urological Pathology (ISUP) consensus conference on handling and staging of radical prostatectomy specimens, 65.5% of the attendants answered that the current pT2 susbstaging system should not be used. Answering to another question, 63.4% favored to be reduced to two categories based on studies showing that pT2b does not exist. There was no consensus in regard to a minimum size for a second tumor to be considered for the whole case to be classified as pT2c as well as in regard to the definition of index tumor. We compared clinicopathologic findings and biochemical progression following surgery classifying pT2 patients into two categories.
Design: The study was based on whole-mount consecutive surgical specimens from 142 patients with organ confined cancer. Using a semiquantitative method for evaluation of tumor extent, 10 positive points corresponds roughly to a 0.5ml tumor. We considered pT2a/pT2b substage (group 1) whenever a tumor presented >10 positive points on only one side and pT2c whenever presented >10 positive points on each of right and left side (group 2). The variables analyzed were: age, preoperative PSA, clinical stage, Gleason score on needle biopsy, and biochemical progression following surgery defined as PSA > 0.2ng/mL. The data were analyzed using the Mann-Whitney test, and the Kaplan-Meier product-limit analysis using the log-rank test for comparison between the groups. The P-values were two-sided at the significance level of <0.05.
Results: Substage pT2a/pT2b corresponded to 84/142 (59.2%) patients and substage pT2c to 58/142 (40.8%) patients. There was no statistically significant difference between the groups in relation to: age (p=0.30), preoperative PSA (p=0.13), clinical stage (p=0.34), and Gleason score on needle biopsy (p=0.27). In 5 years of follow-up, 61% of patients pT2a/pT2b and 71% of patients pT2 were free of biochemical progression (log-rank, p=0.68).
Conclusions: There was no significant difference for several clinicopathological variables and time of biochemical progression following surgery between patients with stage pT2a/pT2b and patients with stage pT3c. The results of this study favor to discontinue using the current pT2 substaging system for reporting of radical prostatectomy specimens.
Category: Genitourinary (including renal tumors)

Tuesday, March 23, 2010 11:15 AM

Platform Session: Section A, Tuesday Morning


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