Bilateral Seminal Vesicle Invasion as a Strong Prognostic Indicator in T3b Prostate Cancer Patients Following Radical Prostatectomy: A Comprehensive, Multicenter, Long-term Follow-up Study.

Purpose: Pathologic T3b (pT3b) prostate cancer, characterized by seminal vesicle invasion (SVI), exhibits variable oncological outcomes post-radical prostatectomy (RP). Identifying prognostic factors is crucial for patient-specific management. This study investigates the impact of bilateral SVI on prognosis in pT3b prostate cancer.

Materials and methods: We evaluated the medical records of a multi-institutional cohort of men who underwent RP for prostate cancer with SVI between 2000 and 2012. Univariate and multivariable analyses were performed using Kaplan-Meier analysis and covariate-adjusted Cox proportional hazard regression for biochemical recurrence (BCR), clinical progression (CP), and cancer-specific survival (CSS).

Results: Among 770 men who underwent RP without neo-adjuvant treatment, median follow-up was 85.7 months. Patients with bilateral SVI had higher preoperative prostate-specific antigen levels and clinical T category (all p < 0.001). Extracapsular extension, tumor volume, lymph node metastasis (p < 0.001), pathologic Gleason grade group (p < 0.001), and resection margin positivity (p < 0.001) were also higher in patients with bilateral SVI. The 5-, 10-, and 15-year BCR-free survival rates were 23.9%, 11.7%, and 8.5%; CP-free survival rates were 82.8%, 62.5%, and 33.4%; and CSS rates were 96.4%, 88.1%, and 69.5%, respectively. The bilateral SVI group demonstrated significantly lower BCR-free survival rates, CP-free survival rates, and CSS rates (all p < 0.001). Bilateral SVI was independently associated with BCR (hazard ratio, 1.197; 95% confidence interval, p=0.049), CP (p=0.022), and CSS (p=0.038) in covariate-adjusted Cox regression.

Conclusion: Bilateral SVI is a robust, independent prognostic factor for poor oncological outcomes in pT3b prostate cancer.