Impact of urinary diversion type on urethral recurrence following radical cystectomy for bladder cancer: propensity score matched and weighted analyses of retrospective cohort

Abstract

Background: The absence of randomized controlled trials and the presence of inherent selection bias in existing studies have led to ongoing uncertainty regarding the impact of urinary diversion (UD) type (orthotopic UD or nonorthotopic UD) on urethral recurrence (UR) following radical cystectomy (RC) for bladder cancer. This study aimed to assess the impact of the UD types on UR after RC and to identify predictive factors associated with UR.

Materials and methods: This retrospective analysis encompassed 612 male patients who underwent RC for urothelial carcinoma of the bladder. Among them, 341 patients received nonorthotopic UD [ileal conduit (IC) or ureterocutaneostomy (UC)], whereas 271 received orthotopic neobladder (NB) between January 2012 and October 2022. To mitigate potential biases, we employed 1:1 propensity score matching (PSM) and stabilized inverse probability treatment weighting (IPTW). Kaplan-Meier analysis and log-rank tests were employed to assess UR-free survival between the IC/UC and NB groups, while multivariable Cox regression analysis was conducted to determine predictive factors for UR.

Results: Among the 612 patients included, 33 (5.4%) experienced UR. PSM yielded matched cohort comprising 412 patients, evenly distributed with 206 patients in each group (IC/UC and NB). Clinicopathological data demonstrated similarity between the two groups. Patients who underwent NB exhibited significantly superior UR-free survival in both PSM (log-rank P =0.033) and IPTW cohorts (log-rank P =0.009). NB reconstruction (vs. IC/UC) emerged as a substantial protective factor against UR [hazard ratio (HR) 0.283; 95% CI: 0.088-0.916; P =0.035], whereas prostatic urethral involvement was identified as a significant risk factor (HR 5.328; 95% CI: 1.298-21.868; P =0.020) in the PSM cohort. Additionally, in the IPTW cohort, NB reconstruction (vs. IC/UC) maintained its significance as a protective factor against UR (HR 0.336; 95% CI: 0.131-0.858; P =0.023) along with neoadjuvant chemotherapy (HR 0.335; 95% CI: 0.116-0.969; P =0.044), whereas prostatic urethral involvement remained a significant risk factor (HR 3.752; 95% CI: 1.484-9.488; P =0.005).

Conclusions: Even after mitigating selection bias, NB reconstruction holds a protective effect against UR in male patients undergoing RC for bladder cancer.