A Multi-Institutional Comparison of Clinicopathological Characteristics and Oncologic Outcomes of Upper Tract Urothelial Carcinoma in China and the United States.

PURPOSE: We evaluated differences in clinicopathological characteristics and oncologic outcomes between patients with upper tract urothelial carcinoma in mainland China and the United States.

MATERIALS AND METHODS: We retrospectively compiled clinicopathological and oncologic outcomes data on patients with upper tract urothelial carcinoma treated surgically at tertiary care medical facilities in the United States or China from 1998 to 2015. Baseline demographics, comorbidities and pathological features were evaluated. Oncologic end points, including intravesical recurrence and cancer specific survival, were obtained after excluding patients who received systemic chemotherapy. Multivariable Cox regression was performed to determine predictors of adverse oncologic outcomes for each country.

RESULTS: A total of 775 patients with upper tract urothelial carcinoma were identified, including 451 in China and 324 in the United States. Median followup was 42 months. American patients were more frequently male (65% vs 44%) and smokers (79% vs 18%), and had a worse mean ASA® (American Society of Anesthesiologists®) score (2.7 vs 2.2) and prior bladder cancer (41% vs 4%, all p <0.001). Chinese patients more often had preoperative hydronephrosis (56% vs 40%), high grade pathology (98% vs 77%), muscle invasion (64% vs 38%) and nodal metastases (26% vs 6%, all p <0.001). American patients had worse overall survival on Kaplan-Meier analysis (p = 0.049). However, country of origin did not predict local relapse or cancer specific survival.

CONCLUSIONS: Patient and disease characteristics of upper tract urothelial carcinoma differed between the Chinese and American cohorts. Chinese patients appeared relatively healthier at presentation but more often exhibited adverse pathological features. While evaluation and management patterns may account for these variations, the pathological findings may reflect a differential underlying pathogenesis of disease. Additional study is warranted to further characterize these differences.