Background and purpose: With the widespread early detection programs for prostate cancer, there has been a downward stage migration and a marked decrease in the percentage of men with seminal vesicle invasion (SVI) compared with previous data. We evaluated clinicopathologic findings that are associated with SVI to select patients for potential seminal vesicle-sparing surgery.
Patients and methods: We reviewed our radical prostatectomy database from 1997 to 2006 to evaluate the incidence and clinical correlates of SVI. Variables analyzed included serum prostate-specific antigen (PSA) level, clinical stage, percentage of positive cores with cancer, Gleason score on biopsy, age, prostate weight, and urethral and vesical surgical margins. Statistical analysis included univariate and multivariate logistic regressions.
Results: Of 267 patients, 32 (12%) had SVI. Preoperative PSA level, biopsy Gleason score, and percentage of positive cores were highly predictive of SVI on multivariate analysis. SVI was present in only 1/98 patients (1.02 %) with biopsy Gleason score ≤6, 0/23 patients (0%) with serum PSA level <4 ng/mL, and only 1 patient with ≤12.8% of positive cores on biopsy. In all cases of distal SVI, there was proximal involvement.
Conclusion: Serum PSA level, Gleason score, and percentage of positive cores on biopsy are statistically significant predictors of SVI on multivariate analysis. Seminal vesiculectomy does not benefit almost 99% of patients with biopsy Gleason score ≤6, PSA level <4 ng/mL, and with <12% cores with cancer. In cases of seminal vesicle-sparing surgery, frozen section of the proximal portion may be of adjunct usefulness for the triple.