Cox and logistic regression were performed to determine predictors of adverse oncologic outcomes for each country and the cohorts were compared. RESULTS: 775 UTUC patients were identified including 451 Chinese patients and 324 US patients. Median overall follow-up was 41 months. 100% of Chinese and 87% of US patients underwent nephroureterectomy. US patients with UTUC were more frequently male (65% vs. 44%, p<0.001), were more often tobacco users (79% vs. 18%, p<0.001), had worse baseline eGFR (61 vs 66 ml/min/1.73 m 2 , p¼0.004), had worse mean ASA score (2.7 vs. 2.2, p<0.001), and were more likely to have had prior bladder cancer (41% vs. 4%, p<0.001) than Chinese patients. Chinese patients more often had pre-operative hydronephrosis (56% vs. 40%, p<0.001), positive voided cytology (52% vs. 14%, p<0.001), sessile architecture (28% vs. 14%, p¼0.028), highgrade pathology (98% vs. 78%, p<0.001), pT2 stage (64% vs. 40%, p<0.001), and pN+ (26% vs. 9%, p¼0.001). While US patients more often experienced bladder recurrence (44% vs. 30%, p<0.001), contralateral upper tract relapse was not significantly different. CSM was higher in Chinese patients (30% vs. 20%, p¼0.001). Country of origin did not predict local relapse or CSM on Cox regression. CONCLUSIONS: Patient and disease characteristics of UTUC appear to differ between Chinese and US cohorts. Chinese patients are healthier at presentation but more often exhibit adverse pathologic features. While screening and management patterns likely differ between the two countries, the pathologic findings may reflect the underlying biology of disease, and additional study is warranted to further characterize these differences.