Comparison of different prediction tools for the risk of intravesical recurrence after radical nephroureterectomy for upper tract urothelial carcinoma: a propensity-matched analysis

To compare the predictive performance of the current clinical prediction models for predicting intravesical recurrence (IVR) after radical nephroureterectomy (RNU) in patients with upper tract urothelial carcinoma (UTUC). We retrospectively analysed upper tract urothelial carcinoma patients who underwent radical nephroureterectomy in our centre from January 2009 to December 2019. We used the propensity score matching (PSM) method to adjust the confounders between the IVR and non-IVR groups. Additionally, Xylinas’ reduce model and full model, Zhang’s model, and Ishioka’s risk stratification model were used to retrospectively calculate predictions for each patient. Receiver operating characteristic (ROC) curves were generated, and the areas under the curves (AUCs) were compared to identify the method with the highest predictive value. We included 217 patients with a median follow-up of 41 months, of which 57 had IVR. After PSM analysis, 52 pairs of well-matched patients were included in the comparative study. No significant difference was found in clinical indicators besides hydronephrosis. The model comparison showed that the AUCs of the reduced Xylinas’ model for 12 months, 24 months, and 36 months were 0.69, 0.73, and 0.74, respectively, and those of the full Xylinas’ model were 0.72, 0.75, and 0.74, respectively. The AUC of Zhang’s model for 12 months, 24 months, and 36 months was 0.63, 0.71, and 0.71, respectively, the performance of Ishioka’s model is that the AUC of 12 months, 24 months and 36 months was 0.66, 0.71, and 0.74, respectively. The external verification results of the four models show that more comprehensive data and a larger sample size of patients are needed to strengthen the models’ derivation and updating procedure, to better apply them to different populations.