Oncologic outcomes according to the extent of prostatic involvement after radical cystectomy: A comparison of prostatic urethral and stromal invasion

Background Orthotopic neobladder (ONB) is no longer contraindicated when the distal urethral frozen section (DFS) is negative and only prostatic urethral involvement (PUI) or prostatic stromal invasion (PSI) is present. However, pathology-specific long-term oncologic outcomes remain poorly defined. Methods We retrospectively analyzed 192 margin-negative, pN0M0 men with histologically confirmed PUI or PSI who underwent radical cystectomy between 1996 and 2024. Primary endpoints were urinary tract recurrence (UTR) and distant metastasis. Multivariable Cox regression was performed for distant metastasis. Results Among 192 patients, 54 (28.1%) had PSI and 138 (71.9%) had PUI. ONB was performed in 164 patients (85.4%) and ileal conduit/ureterocutaneostomy (IC/UC) in 28 (14.6%). Over a mean follow-up of 40 months, UTR occurred in 17 patients (8.8%) and was more frequent in PSI than PUI (14.8% vs. 6.5%; HR 3.39, 95% CI 1.31–8.80; p=0.012). Distant metastasis developed in 52 patients (27.1%) and was also more common in PSI (44.4% vs. 20.3%; p<0.001). On multivariable analysis, PSI independently predicted distant metastasis (HR 2.54, 95% CI 1.37–4.72; p=0.003). Metastasis rates did not differ significantly according to diversion type (p=0.165). Conclusions PSI was associated with significantly worse oncologic outcomes than PUI following radical cystectomy. These findings suggest that recurrence and metastatic progression are driven primarily by the extent of prostatic invasion rather than diversion type. ONB after a negative DFS appears oncologically acceptable in carefully selected patients, although PSI warrants closer surveillance.