[802] Prostate Total Tumor Extent vs. Index Tumor Extent: Which Is Predictive of Biochemical Recurrence Following Radical Prostatectomy?

Athanase Billis, Luciana Meirelles, Leandro LLL Freitas, Aline S Polidoro, Hamilton A Fernandes, Mariana M Padilha, Luis A Magna, Leonardo O Reis, Ubirajara Ferreira. University of Campinas (Unicamp) School of Medicine, Campinas, SP, Brazil

Background: It is controversial whether tumor extent or volume in radical prostatectomies is predictive of biochemical recurrence following surgery. We compared the predictive value of total tumor extent vs. predominant nodule extent (index tumor).
Design: A mean of 32 paraffin blocks were processed from prostate surgical specimens step-sectioned at 3 to 5mm intervals from 300 patients submitted to radical retropubic prostatectomy (RP). Each transversal section of the prostate was subdivided into 2 anterolateral and 2 posterolateral quadrants. Tumor extent at RP was evaluated by a semiquantitative point-count method previously described. Time to biochemical recurrence following RP was analyzed with the Kaplan-Meier product-limit analysis using the log-rank test for comparison between the groups and prediction of time to biochemical recurrence using univariate and multivariate Cox proportional hazards model.
Results: Considering the total tumor extent, more extensive tumors showed higher preoperative PSA (p<0.01), higher clinical stage (p=0.02), higher pathological stage (p<0.01), higher positive margins (p<0.01), and higher Gleason score in RP (p<0.01). More extensive tumors showed significantly shorter time to biochemical recurrence (log-rank, p=0.04). Using Cox proportional hazards model, total tumor extent was predictive of time to biochemical recurrence in univariate analysis (p<0.01) but not in multivariate analysis including preoperative PSA and all pathological parameters. Considering the index tumor extent, more extensive tumors showed higher preoperative PSA (p<0.01), higher clinical stage (p=0.01), higher pathological stage (p<0.01), higher positive margins (p<0.01), and higher Gleason score in RP (p<0.01). More extensive index tumors showed significatly shorter time to biochemical recurrence (log-rank, p<0.01). Using Cox proportional hazards model, index tumor extent was significantly predictive of time to biochemical recurrence in univariate (p<0.01) as well as multivariate analysis with the forward selection and including preoperative PSA and all pathological parameters.
Conclusions: Based on our study, total tumor extent is significantly predictive of time to biochemical recurrence following RP but only index tumor extent is predictive on both univariate and multivariate analyses including preoperative PSA and all pathological parameters.
Category: Genitourinary (including renal tumors)

Tuesday, March 20, 2012 11:45 AM

Platform Session: Section A, Tuesday Morning

 

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