Validation of EAU Guideline’s Pretreatment Risk Stratification Parameters in Upper Tract Urothelial Carcinoma (UTUC)
European Association of Urology (EAU) Guidelines recently renewed the criteria for pre-treatment risk stratification as exclusion criteria for kidney-sparing surgery (KSS). Our aim was to evaluate the additive value of each factor including the whole model for identifying advanced pathologic stage after RNU.
We conducted a multi-institutional retrospective study that included 406 patients who underwent ureterorenoscopy with biopsy followed by radical nephroureterectomy (RNU) for non-metastatic UTUC between 2000 and 2017. Patients who received preoperative chemotherapy were excluded. We performed logistic regression analyses with area under the curve receiver operating characteristics (AUC-ROC) to compare the different factors in predicting ≥pT2 pathologic stage. Furthermore, we conducted decision curve analysis to assess the clinical net benefit and net reduction.
Overall, 146 (35.6%) patients had a high-grade biopsy, 94 (23.2%) high-grade cytology, 39 (9.6%) invasive disease in computed tomography urography (CTU), 201 (49.5%) tumor size >2 cm, 112 (27.6%) preoperative hydronephrosis, 18 (4.4%) previous cystectomy and 80 (19.7%) multifocal disease. The final RNU pathology revealed 173 (42.6%) patients with ≥pT2 disease. In a preoperative multivariable model, biopsy high-grade (OR 4.44, p<0.001), CTU invasion (OR 4.19, p<0.001), tumor size >2 cm (OR 1.75, p=0.013) and high-grade cytology (OR 1.72, p=0.039) were independently associated with muscle-invasive pathologic stage. On the other hand, preoperative hydronephrosis, previous cystectomy and multifocality were not. The addition of these three factors improved the model’s accuracy from 74 to 75% and the negative predictive value (NPV) from 89 to 90%. Decision curve analyses showed a maximum clinical net benefit of 0.19 at the threshold probability of 0.25 for the model with biopsy grade, cytology, CTU invasion and tumor size >2cm. Preoperative hydronephrosis, previous cystectomy and multifocality did not convey any clinical net benefit nor net reduction to this model.
High-grade ureteroscopic biopsy and cytology, CTU invasion and tumor size >2cm seem to be the best factors to identify patients who harbor muscle-invasive disease within a box model. The additive value of preoperative hydronephrosis, previous cystectomy and tumor multifocality could be limited. Further biomarkers are needed to best identify the patients who could most likely benefit from endoscopic KSS.