Impact of ureteroscopy on nephroureterectomy and standards of care compliance in upper tract urothelial carcinoma: the BAUS UK I-DUNC audit.

Abstract

To evaluate diagnostic practices in the United Kingdom (UK) prior to radical nephroureterectomy (RNU) for suspected upper tract urothelial carcinoma (UTUC) and assess their impact on early oncological outcomes. The audit examined compliance post-operative intravesical Mitomycin C (MMC) instillation and adjuvant chemotherapy for ≥pT2 disease. This national audit, by the British Association of Urological Surgeons (BAUS), invited all NHS hospitals performing RNU for non-metastatic UTUC. Retrospective anonymised data were collected. Outcomes included time from imaging to RNU, use of MMC, adjuvant chemotherapy, bladder recurrence, surgical margins, extravesical metastasis, and final histology. Statistical analysis used Mann-Whitney U, Chi-square/Fisher's exact test, and multivariate logistic regression. A total of 877 patients who underwent RNU across 70 hospitals were analysed (median 10 cases per hospital). Diagnostic ureteroscopy (d-URS) was performed in 61.3% of cases, delaying RNU by a median of 53 days (130 vs 77 days; P < 0.01). Voided urine cytology was recorded in 34.3%. Among patients with high-grade and/or ≥ pT1 disease, 89% had positive cytology. MMC was administered in 45.1% of ≥pT2 cases and adjuvant chemotherapy in 46%. Bladder recurrence was significantly higher in patients undergoing d-URS (26.6% vs 12.3%; P < 0.01), as were positive margins in ≥pT2 tumours (24% vs 14%; P = 0.03). Although not statistically significant, d-URS was associated with more metastases (27.2% vs 19.2%) and fewer non-UTUC diagnoses (5.5% vs 8.6%). Multivariate analysis showed that d-URS independently predicted bladder recurrence and margin positivity in ≥pT2 disease. Our audit showed that d-URS is associated with significant treatment delays, increased rates of metachronous bladder cancer recurrence, and higher surgical positive margin rates in patients with ≥pT2 disease. Compliance with MMC therapy and adjuvant chemotherapy was low. This national audit highlights the need for risk-stratified diagnostic pathways, multidisciplinary expertise, and establishment of quality performance indicators to improve care and outcomes in UTUC management in the UK.