Oncological and perioperative outcomes of robot-assisted radical cystectomy: a real-world cohort study emulating a target trial

We tried to evaluate the comparative effectiveness of robot-assisted radical cystectomy (RARC) and open radical cystectomy (ORC) using nationwide real-world data within a target trial framework. Nationwide claims were used to identify individuals with bladder cancer who received transurethral resection during 2007–2020. Surgical strategies were defined according to receipt of RARC or ORC during a 1-year grace period. Cloning, censoring, and weighting were used to align treatment strategies from a common time zero and account for treatment-selection and immortal-time biases. The primary outcome was overall survival, with perioperative outcomes and healthcare expenditures examined secondarily. Among 45,595 eligible individuals, surgery within the grace period consisted of ORC in 3,681 and RARC in 358. Weighted analysis showed no evidence of a difference in overall survival (HR, 1.18; 95% CI, 0.96–1.45). Postoperative hospitalization was shorter with RARC than with ORC (18.4 vs. 22.5 days; P < 0.001), and transfusion was required in 51.1% and 70.6%, respectively ( P < 0.001). RARC was associated with lower covered healthcare expenditure between surgery and discharge ( P = 0.030), but cumulative expenditures at 2 and 5 years were comparable between groups. In this nationwide target trial emulation, assignment to RARC did not materially alter overall survival relative to ORC but yielded more favorable perioperative findings. These findings support RARC as a surgical alternative to ORC while highlighting the value of target trial emulation for evaluating real-world surgical outcomes.