Incidence, characteristics, treatment strategies, and oncologic outcomes of synchronous bilateral upper tract urothelial carcinoma in the Chinese population

ObjectivesTo investigate the incidence and treatment strategies for bilateral upper tract urothelial carcinoma (UTUC) and to compare the characteristic and oncologic outcomes of bilateral UTUC with those of unilateral tumors.Methods and materialsThe study included 892 consecutive patients with UTUC. Bilateral UTUC was defined as synchronous bilateral carcinoma on preoperative imaging before confirmation by pathology or positive urine cytology result plus direct visualization. Radical nephroureterectomy (RNU) or nephron-sparing surgery (NSS) or both were carried out.ResultsA total of 39 patients (4.37%) suffered from bilateral disease. Discordant histological grade of bilateral tumor was found in 39.3% cases. Bilateral tumors were associated with female sex (P<0.001), preoperative renal insufficiency (P<0.001), previous or concomitant bladder tumors (P = 0.013), lower tumor stages (P = 0.020), papillary architecture (P = 0.001), and smaller-sized tumors (P = 0.020). Patients with worse renal function (P<0.001) or large-sized tumors (P = 0.039) tended to be treated with bilateral RNU. Most patients (67.6%) were treated with unilateral RNU plus unilateral NSS, with NSS being performed on tumors that only extended to the ureter (P = 0.003) and had a smaller size (P = 0.005). The median follow-up duration was 56 months. The 5-year cancer-specific survival and bladder recurrence-free survival rates were 81.2% and 64.5%, respectively, similar to those of unilateral tumors. Male sex (hazard ratio = 11.535) and higher tumor stage (hazard ratio = 3.386) were independent worse prognostic factors.ConclusionsThe prevalence of bilateral UTUC is rare. Female patients, patients with renal insufficiency, and those with bladder tumor tended to suffer from bilateral disease and were less likely to present with worse pathological outcomes in the Chinese population. The tumor characteristics and renal function were informative in treatment selection. The oncologic outcomes were similar to those in unilateral UTUC, and male sex and a higher tumor stage were poor prognostic factors for these patients.