Abstract
OBJECTIVE: Clinical features of upper tract urothelial carcinoma (UTUC) vary widely across countries. We aimed to provide clinical observations and compare oncological outcomes among regions in East Asia and Europe. METHODS: This retrospective study (March 2000 to July 2020) included 664 UTUC patients undergoing radical nephroureterectomy in China, Japan, the Republic of Korea, and Germany. Cohorts from China comprised patients from the Hong Kong Special Administrative Region and the Taiwan region, respectively. Demographic and clinicopathological parameters were analyzed. Continuous variables were analyzed using the Student's t-test, and categorical variables were assessed using the Pearson's chi-square test. The Cox proportional hazards model was employed to evaluate overall survival (OS), cancer-specific survival (CSS), and bladder recurrence-free survival across regions and various parameters. RESULTS: Females had a higher proportion of patients than males only in Taiwan, China. Few patients received preoperative ureteroscopic biopsy prior to radical surgery in Seoul, the Republic of Korea. In the multivariate analysis, patients' regional origin was not associated with worse OS and CSS. Older age, multifocal tumors, high pT stage (pT4), positive lymphovascular invasion, and distant metastasis were associated with worse OS. High pT stage (pT4) and distant metastasis were independent factors leading to worse CSS. Patients' regional origin (Seoul, the Republic of Korea; Schleswig-Holstein, Germany; and Chiba, Japan) was associated with worse bladder recurrence-free survival. The preoperative ureteroscopic biopsy did not increase the intravesical recurrence. CONCLUSION: This international observational study revealed variations in the epidemiological distributions and practice patterns among UTUC patients in China, Japan, the Republic of Korea, and Germany. Cohorts from China comprised patients from the Hong Kong Special Administrative Region and the Taiwan region, respectively. However, ethnic and regional differences did not affect OS and CSS after radical nephroureterectomy.