Abstract
<title>Abstract</title> <p>Purpose Bladder cancer extension into the prostatic urethra is a well-known risk factor for urethral recurrence. This study investigated whether concurrent involvement of the intramural ureter, in addition to the prostatic urethra, further increases the urethral cancer risk. Methods We retrospectively analyzed 316 male patients who underwent radical cystectomy for bladder cancer between 2002 and 2020. We assessed the prevalence of tumor extension into the prostatic urethra and intramural ureter and evaluated its association with synchronous and metachronous urethral cancer. Synchronous urethral cancer was defined as cancer detected in the pendulous, bulbar, or membranous urethra, whereas metachronous urethral cancer was defined as cancer developing in the remnant urethra. Logistic regression analyses were performed to identify urethral cancer risk factors. Results The median follow-up duration was 61 months. Among the 316 patients, 148 underwent prophylactic urethrectomy during cystectomy, and 168 did not. Urethral cancer occurred in 12 (3.8%): 8 (5.4%) had synchronous urethral cancer, and 4 (2.4%) developed metachronous urethral cancer. In multivariate analysis, the odds ratios for urethral cancer were 3.91 (95% confidence interval [CI], 0.84–18.20; p = 0.082) for cancer extension limited to the prostatic urethra and 12.6 (95% CI, 2.75–57.60; p = 0.001) for cancer extension to both the prostatic urethra and the intramural ureter compared to no cancer extension to the prostatic urethra. Conclusion Two distinct patterns of prostatic urethral involvement exist. Bladder cancer extending into both the prostatic urethra and the intramural ureter was strongly associated with synchronous and metachronous urethral cancers.</p>