Are urothelial carcinomas of the upper urinary tract a distinct entity from urothelial carcinomas of the urinary bladder? Behavior of urothelial carcinoma after radical surgery with respect to anatomical location: A case control study

Background: To compare the prognosis of upper urinary tract (UUT)-urothelial carcinoma (UC) and UC of the bladder (UCB) by pathological staging in patients treated with radical surgeries. Methods: The study population comprised 335 and 302 consecutive radical surgery cases performed between 1991 and 2010 for UUT-UC and UCB, respectively. Five-year recurrence-free survival (RFS) and cancer-specific survival (CSS) rates were analyzed. The median follow-up period of all subjects was 59.3 months (range, 0.1-261.0 months). Results: No difference was observed in median patient age, distribution of pathologic T stage, or rates of positive surgical margin between the two groups. The UUT-UC group had significantly more frequent hydronephrosis than the USB group (48.1% vs. 20.2%, p < 0.001). However, the UUT-UC group showed significantly less frequent grade III tumors (28.1% vs. 58.6%, p < 0.001), lymphovascular invasion (18.8% vs. 35.8%, p < 0.001), and associated carcinoma in situ (9.0% vs. 21.9%, p < 0.001) than the UCB group. Five year RFS rates in the UUT-UC and UCB groups were 77.0% and 75.9%, respectively (p = 0.546). No significant difference in RFS rate was observed between pathological T stage subgroups. Five year CSS rates in the UUT-UC and UCB groups were 76.1% and 76.2%, respectively (p = 0.462). No significant difference was observed in CSS rate between the pathologic T stage subgroups. Conclusions: UUT-UC and UCB showed comparable prognosis at identical stages. However, our results should be verified in a prospective study due to the retrospective study design in this study.