Tumor Location Based Segmentation in Upper-Tract Urothelial Carcinoma Impacts on the Urothelial Recurrence-Free Survival: A Multi-Institutional Database Study

Introduction and Objectives: The predictive impact of primary tumor location for patients with upper-tract urothelial carcinoma (UTUC) in the presence of concomitant urothelial bladder cancer, along with urothelial recurrence after the curative treatment is still contentious. We evaluated the association between precise tumor location and concomitant presence of urothelial bladder cancer and urothelial recurrence-free survival in patients with UTUC treated by radical nephroureterectomy with a bladder cuff. Methods: A total of 1,349 patients with localized UTUC (Ta-4N0M0) from a retrospective multi-institutional cohort were studied. We queried four UTUC databases. This retrospective clinical series was of patients with localized UTUC managed by nephroureter-ectomy with a bladder cuff, for whom data were from the Nishinihon Uro-Oncology Collaborative Group registries. Patients with a history of chemotherapy or radiotherapy were excluded from the study. Associations between the location of the tumor and subsequent outcome following nephroureterectomy were assessed using COX multivariate analysis. The location of the tumor was verified by pathological samples. Urothelial recurrence was defined as tumor relapse in any local urothelium, and coded apart from distant metastasis. The median follow-up was 34 months. Results: A total of 887 patients had an evaluation of the tumor location in which 475 patients had pelvic tumors (53.6%), 96 had ureteral tumors in the U1 segment (10.8%), 87 in the U2 segment (9.8%), and 176 in the U3 segment (19.8%). There were 52 patients who had multifocal tumors (5.9%) as follows: 8 (0.9%) in the pelvis and ureter, 11 (1.2%) in U1 + U2, 1 (0.1%) in U1 + U3, 27 (3.0 %) in U2 + U3, and 6 (0.7%) in U1 + U2 + U3. In all, 145 (16.3%) had concomitant bladder tumors. Logistic regression analysis of gender, age, hydronephrosis, cytology, performance status, grade, lymphovascular invasion, pT, pN, and tumor focality showed that tumor location was associated with the presence of concomitant bladder cancer (p = 0.004, HR = 1.265). When the tumor location was stratified into 8 segments, including multifocal tumors, only the U3 segment remained as a predictor for the presence of concomitant bladder cancer (p = 0.002, HR = 2.872). Kaplan-Meier analysis for unifocal disease showed that lower ureter tumors (a combination of U2 and U3) had a worse prognosis for urothelial recurrence than pelvic tumors or upper ureteral tumors (U1) (p < 0.001 for lower ureteral tumors versus pelvic tumors, p = 0.322 for upper ureteral tumor versus pelvic tumor by log rank). Multivariate analysis showed that lower ureter remained as a prognostic factor for urothelial recurrence after adjusting for gender, age, hydronephrosis, urine cytology, lymphovascular invasion, pT, and pN (p < 0.001, HR = 1.469), and a similar tendency was found when the analysis was run for patients without concomitant bladder tumors (p = 0.003, HR = 1.446). Patients with lower ureteral tumors had a higher prevalence of deaths (HR = 2.227) compared to patients with upper ureter tumors. Conclusions: This multi-institutional study showed that the primary tumor locations were independently associated with the presence of concomitant bladder tumors and subsequent urothelial recurrence.