Perioperative Systemic Treatment Patterns and Postoperative Mortality Among Patients With Muscle‐Invasive Bladder Cancer Undergoing Radical Cystectomy in Japan: WAKKA ‐ MIBC Study

OBJECTIVES: To characterize the temporal changes in perioperative systemic treatment patterns and postoperative mortality among Japanese patients with stage II-III muscle-invasive bladder cancer (MIBC) undergoing radical cystectomy (RC) from 2013 to 2024. METHODS: This retrospective observational cohort study assessed neoadjuvant chemotherapy (NAC) and adjuvant therapy (AT) relative to RC. Treatment patterns (NAC + RC + AT, NAC + RC, RC + AT, and RC alone), NAC regimen selection, and 30- and 90-day postoperative mortality were evaluated across three periods (2013-2017, 2018-2021, and 2022-2024). Analyses were descriptive. RESULTS: Among 5 208 patients, the use of NAC + RC increased from 31.4% in 2013-2017 to 50.4% in 2022-2024, and the use of NAC + RC + AT increased from 8.7% to 22.4%. RC alone decreased from 46.3% to 21.4%. Reduced-dose gemcitabine + cisplatin (GC) and gemcitabine + carboplatin were frequently used and remained common throughout the study period. In 2022-2024, 18.8% of patients received adjuvant nivolumab; most had received NAC beforehand (242/270). The 30- and 90-day mortality remained low regardless of the increase in NAC use (30-day: ≤ 0.2% with NAC vs. ≤ 1.5% without; 90-day: ≤ 1.4% with NAC vs. ≤ 3.3% without). CONCLUSIONS: Perioperative systemic therapy for MIBC in Japan has intensified over the past decade, with increased adoption of NAC and adjuvant nivolumab. Dose-modified GC and carboplatin-based regimens have remained commonly used throughout the study period. Even with increased NAC use, postoperative mortality has remained low.