Abstract
OBJECTIVE: To investigate the impact of histological variants (HV) in patients with upper tract urothelial carcinoma (UTUC) and analyze the potential association between HV and postoperative bladder recurrence. MATERIALS AND METHODS: The medical records of UTUC patients treated with RNU at our center from January 2012 to December 2019 were retrospectively analyzed. Patients were grouped according to the types of HV. Clinicopathological features and prognostic factors were compared among groups. RESULTS: A total of 629 patients were included in the study: 458 (73%) patients had pure urothelial carcinoma (PUC) and 171 (27%) patients had UTUC with HV. Squamous differentiation was the most common type (124 cases, 19%), followed by glandular differentiation (29 cases, 5.0%). Patients with HV had a higher proportion of T3 and T4 pathologic stages (P < 0.001) as well as high-grade disease (P = 0.002). In the univariate analysis, squamous differentiation and glandular differentiation were significantly associated with worse cancer-specific survival (CSS) (HR 2.22, 95% CI 1.62-3.04, P < 0.001; HR 1.90, 95% CI 1.13-3.20, P = 0.016). However, the multivariate analysis showed that this association became non-significant. We found that HV were associated with recurrent muscle-invasive bladder cancer (MIBC) after RNU and all patients had T2 and T3 initial tumor stages (P = 0.008, P < 0.001). CONCLUSION: We found that UTUC patients with HV were associated with biologically aggressive disease and recurrent MIBC after RNU. The detection of bladder recurrence following surgery needs to be given more attention in advanced UTUC patients with HV.