A Multicenter Retrospective Cohort Series of Muscle-invasive Bladder Cancer Patients Treated with Definitive Concurrent Chemoradiotherapy in Daily Practice

Background Concurrent chemoradiotherapy (CRT) as a definitive treatment option for patients with nonmetastatic muscle-invasive bladder carcinoma (MIBC) is increasingly being applied in clinical practice. Objective To assess the oncological and toxicity outcomes in a contemporary cohort of nonmetastatic MIBC patients treated with concurrent CRT in daily practice. Design, setting, and participants Patients with nonmetastatic MIBC (cT2-4aN0M0) who had received CRT with curative intent between January 2010 and April 2020 in three centers were retrospectively identified. The CRT consisted of 66 Gy (or biologically equivalent) plus either mitomycin C and fluorouracil/capecitabine or cisplatinum. Outcome measurements and statistical analysis The primary endpoint was the 2-yr locoregional disease-free survival (LDFS) estimate. Secondary endpoints were complete response, disease-specific survival (DSS), overall survival (OS), bladder intact event-free survival (BI-EFS), and severe adverse events (<90 d of starting CRT). Kaplan-Meier survival and Cox multivariable regression analyses were performed. Results and limitations We included data of 240 MIBC patients with a median age of 74 yr and a median follow-up of 27 mo (interquartile range 11–44). Complete response on first cystoscopy after CRT was seen in 209 cases (90%). The 2-yr LDFS was 76% (95% confidence interval [CI] 70–82%); the 5-yr OS and DSS were 50% (95% CI 42–59%) and 70% (95% CI 62–79%), respectively. On multivariable analysis, cT2 versus cT3–4 tumor stage was significantly associated with better DSS (hazard ratio 1.02, 95% CI 1–1.05, p = 0.024). The 2-yr BI-EFS was 75% (95% CI 69–82%). Forty-three (17%) patients experienced a severe adverse event (grade ≥3). Limitations include retrospective design and heterogeneous administration of CRT. Conclusions Concurrent CRT is a safe and effective treatment modality for nonmetastatic MIBC. Patient summary Chemoradiotherapy for the treatment of muscle-invasive bladder carcinoma is increasingly being applied. In this study, we reviewed the outcomes of this bladder-sparing treatment using a series of patients treated in three hospitals in daily practice. We found that administration of chemoradiotherapy can be safe and effective.