Immediate gemcitabine bladder instillation following bladder closure during robotic-assisted radical nephroureterectomy: a multi-institutional report of feasibility and initial outcomes.

Background: Bladder recurrence after radical nephroureterectomy (RNU) is common and randomized data supports utilization of prophylactic intravesical mitomycin to reduce recurrence. Recently, gemcitabine has been shown to be safe and effective at reducing recurrence following transurethral resection of bladder tumors. We sought to evaluate the safety and efficacy of a single, intraoperative gemcitabine instillation immediately following bladder cuff closure during RNU, and to compare outcomes with non-gemcitabine intravesical chemotherapy agents. Methods: We retrospectively reviewed all patients from two high volume centers who underwent robotic-assisted RNU between 2016-2020 and received either 2 g intravesical gemcitabine immediately following bladder cuff closure or non-gemcitabine intravesical chemotherapies [40 mg mitomycin C (MMC) or 50 mg doxorubicin] at the beginning of the procedure. Clinicopathologic factors were compared between cohorts. Bladder recurrence rates were evaluated using the Kaplan-Meier method and log-rank test. Results: During RNU, 24 patients received gemcitabine and 31 patients received non-gemcitabine chemotherapy. In total, 35% (19/55) of patients experienced a bladder cancer recurrence. There was no significant difference in estimated bladder recurrence-free survival (bRFS) between gemcitabine and non-gemcitabine patient cohorts (P=0.64). By 12 months post-surgery, 25% of patients had experienced bladder recurrence. The estimated 1-year bladder RFS survival was 73% for gemcitabine and 76% for non-gemcitabine chemotherapy. Overall survival and cancer-specific survival did not differ between cohorts. No adverse events potentially attributable to the use of gemcitabine were noted within 30 days postoperatively. Conclusions: Gemcitabine instilled immediately following bladder cuff closure during RNU has similar bRFS rates compared to established chemotherapy agents instilled at the start of surgery.