External Validation of Postoperative Nomograms in Upper Tract Urothelial Carcinoma Following Radical Nephroureterectomy

Background/Objectives: To externally validate and compare four postoperative upper tract urothelial carcinoma (UTUC) nomograms in a contemporary Australian radical nephroureterectomy (RNU) cohort, and to identify independent clinicopathological predictors of survival. Methods: We conducted a retrospective study across a multi-site tertiary service in Victoria of patients who underwent RNU for localised UTUC between January 2011 and December 2021. Patients were excluded if RNU was performed for non-UTUC-related reasons or if they had incomplete data. Univariable and multivariable Cox models assessed prognostic factors. Discrimination of the nomograms was evaluated using Harrell’s C-index with bootstrap-corrected calibration. Results: Of 142 total patients undergoing RNU, 103 were included in the final study cohort. In our multivariable Cox regression analysis, increasing age, sessile architecture and higher tumour stage emerged as independent predictive factors for worse overall survival (OS). For cancer-specific survival (CSS), increasing age, higher tumour stage, tumour location in the kidney, and synchronous tumours in the kidney and ureter were statistically significant. Four nomograms (Seisen, Abdul-Muhsin, Cha and Roupret) were identified. External validation showed the best discrimination of CSS for Seisen (C-index 0.814, 95% confidence interval (CI) 0.687–0.915); Abdul-Muhsin had good OS but moderate CSS discrimination (C-index 0.708 and 0.651), Cha showed good CSS but excellent recurrence-free survival (RFS) discrimination (C-index 0.770 and 0.826) and Roupret CSS nomogram showed good CSS discrimination (C-index 0.789, 95% CI (0.653, 0.900). Conclusions: The Seisen nomogram provided the most accurate, well-calibrated five-year cancer-specific predictions after RNU, outperforming the Abdul-Muhsin, Cha and the Roupret models, likely due to its weighting of age, location, and sessile architecture, which are independent predictors of worse CSS. These data endorse a risk-adapted strategy using the Seisen nomogram to guide postoperative counselling, surveillance intensity, and consideration for adjuvant therapy.