Preoperative parameters, including percent positive biopsy, in predicting seminal vesicle involvement in patients with prostate cancer

Purpose: Complete dissection of the SVs during RP can contribute to increased morbidity including erectile dysfunction and incontinence. Therefore we evaluated the clinical parameters associated with a positive SV finding on final pathology and identified those patients with a minimal risk of SV involvement for potential SV sparing surgery. Materials and Methods: We retrospectively reviewed our RP database from 1991 to 1999 to evaluate the incidence and clinical correlates of SV invasion. Variables studied included preoperative total serum PSA, percent positive biopsy cores, DRE and biopsy Gleason score. Statistical analysis included univariate, multivariate regression analysis and ROC curves. Results: Of our 1,056 patients 79 (7.4%) had SV involvement. Of the 356 patients with less than 17% positive biopsies, only 2 (0.5%) had SV involvement on final pathology. Preoperative PSA, biopsy Gleason score and percent positive biopsies were all highly predictive of SV invasion on multivariate analysis. Percent positive biopsy was found to be the single best predictor of seminal vesicle invasion (p < 0.0001). Conclusions: In our series percent positive biopsy was the single best predictor of SV invasion at the time of RP. An analysis of preoperative parameters including percent positive biopsy, biopsy Gleason score and preoperative PSA may define a subset of patients in which prospective studies could be used to determine the value and safety of SV sparing surgery.