Propensity-score-matched comparison of soft tissue surgical margins status between open and robotic-assisted radical cystectomy

Introduction: The use of robotic-assisted radical cystectomy (RARC) is becoming more widespread. While its safety is accepted, its oncological efficacy as compared to the current standard, open radical cystectomy (ORC), remains debatable. Materials and methods: The aim of this study is to compare the rates of positive soft tissue surgical margins (STSM), between patients treated with RARC or ORC, using a large contemporaneous collaborative database. We included 2,536 patients with urothelial carcinoma of the bladder treated at 26 institutions. A propensity-score matching 1:1 was performed with 3 ORC patients matched to 1 RARC patient. The final cohort included 1,614 patients. Uni- and multivariable logistic regression analyses tested the impact of surgical technique on STSM status, before and after propensity-score matching. Results: Overall, 870 (34%) patients underwent RARC and 1,666 (66%) ORC. The overall STSM rate was 11%; 10% in the ORC group and 13% in the RARC group. Within the propensity-score-matched cohort, the positive STSM rate were 14% and 13% in the ORC and RARC group, respectively (P = 0.1). In multivariable analysis, after propensity match RARC approach was not associated with the risk of a positive STSM (P = 0.1). These results were confirmed in the subgroup of patients with pathologic non–organ-confined or organ-confined diseases. Conclusions: While treatment with RARC is associated with a higher absolute rate of STSM, the difference did not remain after adjustment for the effects of other established prognostic factors. Results from ongoing trials are awaited to assess the validity of these findings.