Oncological outcomes of prophylactic urethrectomy at the time of radical cystectomy for bladder cancer: A nationwide multi-institutional study.

OBJECTIVES:To determine the effects of prophylactic urethrectomy (PU) on oncological and perioperative outcomes in patients with bladder cancer (BC) undergoing radical cystectomy (RC). METHODS:This retrospective study analyzed data on 1976 evaluable patients with BC who underwent RC. Patients were drawn from 36 institutions within the Japanese Urological Oncology Group. Oncological outcomes were compared using restricted mean survival times (RMSTs) based on inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier curves for non-urinary tract recurrence-free survival (NUTRFS), cancer-specific survival (CSS), and overall survival (OS). Interaction terms within IPTW-adjusted Cox regression models were examined to assess the heterogeneity of treatment effect based on the risk of urethral recurrence (UR). The association between PU, estimated blood loss (EBL), and the incidence of severe postoperative surgical complications (SPSCs) (Clavien-Dindo grade 3 or higher) was analyzed. RESULTS:Of 1976 patients, 1448 (73.3%) received PU. IPTW adjustment was used to balance baseline characteristics between the treatment groups. Within the 107-month window of patient monitoring, PU showed no survival benefits (NUTRFS difference: 0.2 months [95% confidence interval: -6.8 to 7.3]; CSS, 1.2 [-4.9 to 7.3]; OS, 0 [-6.5 to 6.5]). No significant interactions were observed with factors associated with UR, and PU was associated with unfavorable perioperative outcomes (EBL, 1179 mL vs. 983 mL; SPSC, 14.6% vs. 7.0%). CONCLUSIONS:This study showed that (1) PU was not associated with survival in patients with BC undergoing RC, regardless of UR-associated factors, and (2) PU was associated with unfavorable perioperative outcomes.