High incidence of and risk factors for metachronous bilateral upper tract urothelial carcinoma in Taiwan

Abstract

Aim: Urothelial carcinoma (UC) can occur multifocally in the whole urothelium. A higher rate of bilateral metachronous upper tract (UT) UC was noted in Taiwan. The incidence and risk factors were largely unknown and hence were explored in the study. Methods: From January 1977 through June 2003, 462 patients with unilateral UT‐UC were studied retrospectively. The cumulative incidence of contralateral recurrence was analysed with the Kaplan–Meier analysis. Potential risk factors for contralateral recurrence including age, smoking, bladder cancer, renal function, diagnostic year etc. were evaluated with the log–rank test. Independent risk factors were identified by using the Cox regression analysis. Results: The median follow‐up time was 34 months (6–337). Among the 462 patients, 52 (11.3%) developed metachronous contralateral UC. The 2, 5, and 10‐year contralateral disease‐free survivals were 93.5%, 84.0%, and 75.7%, respectively. The median time to contralateral recurrence was 31.0 months. With the univariate analysis, only poor renal function (serum creatinine < or ≥2.0 mg/dL, P < 0.001) and late diagnostic year (before or after 1990, P < 0.001) were risk factors for contralateral recurrence. In the multivariate analysis, poor renal function (hazard ratio: 2.98; 95% confidence interval: 1.67–5.33; P < 0.001) and late diagnostic year (hazard ratio: 4.27; 95% confidence interval: 1.71–10.65; P = 0.002) remained independent risk factors. Conclusions: The incidence of metachronous UT‐UC is high in Taiwan. Patients who had either chronic renal insufficiency or a disease diagnosed after 1990 had a higher risk of contralateral recurrence.