Prognostic Significance of Vas Deferens Invasion After Radical Prostatectomy in Patients with Pathological Stage T3b Prostate Cancer

Background: Seminal vesicle invasion (SVI) is associated with adverse clinical outcomes in prostate cancer (PCa) patients. Despite its anatomical similarity and close proximity to the seminal vesicle, the prognostic significance of vas deferens invasion (VDI) by PCa has not been elucidated. For these reasons, we investigated the impact of VDI on the oncological outcome of pT3b PCa in association with SVI. Methods: We retrospectively reviewed the medical records of 3359 patients who had undergone a radical prostatectomy at our institution between January 2000 and December 2014 for PCa. Patients who received neoadjuvant or adjuvant treatment (radiation, androgen deprivation therapy, or both) and those without adequate medical records were excluded. A Kaplan–Meier analysis was performed to analyze biochemical recurrence-free survival (BCRFS), and a Cox regression model was used to test the influence of VDI on biochemical recurrence (BCR). Results: Of 350 patients with pathologically confirmed SVI (pT3b), 87 (24.9%) had VDI, while the remaining 263 patients (75.1%) had isolated SVI. Compared with SVI patients without VDI, SVI patients with VDI were noted to have a significantly worse 5-year BCRFS (25.1 vs. 17.1%, respectively). VDI was a significant predictor of BCR in multivariate Cox regression analysis (hazard ratio 1.39, 95% confidence interval 1.02–1.90; p = 0.039). Conclusions: Our results shows that the prognosis of PCa with SVI might be further stratified by VDI status, thus suggesting the role of VDI either as a surrogate for poor prognosis or as a determinant for adjuvant therapy.