Complete Resection of Seminal Vesicles at Radical Prostatectomy Results in Substantial Long-Term Disease-Free Survival: Multi-institutional Study of 6740 Patients

Abstract

To estimate the disease-specific survival of patients with complete removal of the seminal vesicles (SVs) at radical prostatectomy and to develop a nomogram for the prediction of SV invasion (SVI). An analysis of 6740 patients from three institutions was performed. The primary outcome was biochemical failure analyzed according to the presence or absence of SVI using the Kaplan-Meier method and Cox proportional hazards model. The variables analyzed included age, biopsy Gleason score, clinical T stage, margin status, extracapsular extension, SVI, surgical Gleason score, initial prostate-specific antigen level, and institution. Logistic regression analysis was used to determine the preoperative factors predicting for SVI and create the model for the nomogram. Of the 6740 patients, 566 (8.4%) had positive SVs. The median follow-up was 33.4 months (range 1 to 239). The 5 and 10-year biochemical relapse-free survival rate was 38.0% and 25.6%, respectively, for patients with positive SVs and 85.7% and 77.2%, respectively, for patients with negative SVs (P <0.0001). In the multivariate model, all variables, except for biopsy Gleason score and T stage, were significant predictors of biochemical failure (P <0.05), and all variables, except for age, were predictors of SVI. The nomogram achieved an area under the curve of 0.80. These results have demonstrated that a substantial number of patients with SVI are disease free at 5 and 10 years after complete excision without adjuvant therapy. These findings suggest the therapeutic efficacy of complete SV excision and can identify those with a nomogram-predicted increased risk of SVI who might benefit from complete excision.