Real-world outcomes of definitive chemoradiotherapy for bladder cancer: a multi-institutional retrospective study in Japan.

OBJECTIVE

We aimed to evaluate real-world clinical outcomes and prognostic factors of definitive chemoradiotherapy (CRT) for bladder cancer in Japan.

METHODS

Patients with bladder cancer treated with definitive CRT between 2010 and 2023 at seven Japanese institutions were retrospectively analyzed. Overall survival (OS) was estimated using the Kaplan-Meier method, whereas cause-specific survival (CSS) and bladder preservation were analyzed using competing risk methods. Univariable analyses were performed using the log-rank and Gray's tests, and multivariable analyses were performed using Cox and Fine-Gray models with Bayesian Information Criterion-based stepwise selection.

RESULTS

A total of 175 patients were included. Maximal transurethral resection of the bladder tumor (TUR-Bt) was performed in 55% of patients, and 49% were deemed ineligible for radical cystectomy (RC). The 5-year OS, CSS, and bladder preservation rate were 52% (95% CI, 42-60%), 73% (95% CI, 66-80%), and 69% (95% CI, 61-77%), respectively. In multivariable analyses, poorer performance status remained associated with worse OS (P = .003), whereas advanced clinical T stage was associated with worse CSS (P = .018) and maximal TUR-Bt was associated with improved bladder preservation (P = .024). Although patients ineligible for RC demonstrated inferior OS (P < .001) and CSS (P = .007) in univariable analyses, bladder preservation was comparable to those treated by patient preference.

CONCLUSIONS

This multi-institutional retrospective study demonstrates acceptable real-world outcomes of definitive CRT for bladder cancer in Japan. Patient-related factors influenced OS, whereas tumor burden and local tumor control were associated with CSS and bladder preservation.