2008 Annual Meeting Abstracts

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Tumor Volume is a Predictor of Biochemical Recurrence in Patients With Positive Surgical Margins Following Radical Retropubic Prostatectomy: A Case for Immediate Adjuvant Therapy?
Matthew J Resnick, Daniel Canter, Benjamin M. Brucker, Meredith R. Bergey*, Seema Sonnad*, Alan J. Wein, S. Bruce Malkowicz
University of Pennsylvania School of Medicine, Philadelphia, PA

Introduction:
Patients with positive surgical margins at radical prostatectomy represent a heterogeneous group with a wide range of post-prostectomy outcomes. We aimed to determine the relationship between tumor volume and the risk of biochemical failure in patients with positive surgical margins at radical prostatectomy.
Methods:
We reviewed our database of 2407 patients who underwent radical prostatectomy and isolated 474 total patients (19.7%) with positive surgical margins, 103 of which (4.3%) were found to have pT2 disease, the remainder of which found to have pT3 disease. Kaplan-Meier, log-rank, and multivariate logistic regression analyses were undertaken to assess the relationship between tumor volume and survival.
Results:
Increasing tumor volume, when stratified by quartiles, was directly associated with increasing risk of biochemical failure in those patients with positive surgical margins (p=0.005). The risk of biochemical recurrence at 5- and 10-years was directly related to increasing tumor volume, as presented in Table 1. tumor volume, when incorporated into a multivariable model, strongly trended toward significance in the prediction of biochemical failure (HR=1.41, 95%CI 0.96, 2.06, p=0.076).
Conclusions:
Tumor volume at radical prostatectomy is a predictor of biochemical failure in patients with positive surgical margins. Coupled with other pre- and postoperative parameters, tumor volume may serve to further discriminate those who serve to benefit from immediate adjuvant therapy.

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