Evaluation of Intraoperative Versus Postoperative Adjuvant Mitomycin C with Nephroureterectomy for Urothelial Carcinoma of the Upper Urinary Tract

BACKGROUND: Results of randomized trials support a single dose of intravesical chemotherapy following radical nephroureterectomy (RNU) for urothelial carcinoma. OBJECTIVE: To evaluate the impact of the timing of intravesical mitomycin C (MMC) administration on the rate of bladder tumor recurrence (BTR) following RNU. METHODS: We performed a retrospective review of patients who underwent RNU for upper tract urothelial carcinoma (UTUC) and received intravesical MMC between 2008 and 2016. Patients were categorized into two separate groups based on the timing of MMC administration: patients who received MMC intraoperatively (IO) and patients who received MMC on post-operative day 1 or later (PO). Our primary endpoint was BTR rate within the first year after surgery. RESULTS: Fifty-one patients met our inclusion criteria: (IO: n = 30; PO: n = 21). There were no statistically significant differences in baseline characteristics of age, gender, race, surgical approach, tumor grade, tumor stage, surgical margins, nodal status, concomitant CIS, or history of bladder cancer. The median length of follow-up for each group was 22 months for IO and 12 months for PO (P = 0.10). The estimated probability of 1-year BTR rates for the IO and PO groups were 16% and 33%, respectively (p = 0.09). Cox analysis noted that the IO patients had a significantly lower rate of BTR in the first year postoperatively (HR = 0.113, 95% CI = 0.28–0.63, p = 0.01). CONCLUSIONS: The use of intraoperative MMC at the time of RNU was associated with a decrease in the risk of 1-year recurrence within the bladder.