Prognostic Value of Squamous Differentiation in Upper Tract Urothelial Carcinoma Treated With Radical Nephroureterectomy

Aim: This study retrospectively investigated the impact of squamous differentiation on the prognosis of patients with upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy (RNU). Patients and Methods: Among the 244 consecutive patients who underwent RNU at our Institution from May 2005 to October 2019, 224 were analysed. Metastasis-free (MFS) and overall (OS) survival rates were evaluated using Kaplan-Meier analysis and Cox regression analysis. Results: With a median follow-up time of 58 months, the groups with pure UTUC (n=197) and UTUC with squamous differentiation (n=27) had 5-year MFS rates of 65.2% and 40.9% (p=0.005) and 5-year OS rates of 74.4% and 49.0% (p=0.002), respectively. Multivariate analyses revealed that the presence of squamous differentiation was significantly associated with poor MFS (hazard ratio=1.88; p=0.027) and OS (hazard ratio=1.70; p=0.048). Conclusion: Squamous differentiation in UTUC appears to be an independent predictor of poor prognosis after RNU for UTUC.