Urothelial carcinoma of the bladder in patients aged 30 years or younger: clinicopathological analysis and expression of fibroblast growth factor receptor 3 (FGFR3) of 45 cases.

The aim of this study was to demonstrate the clinicopathological features, prognostic outcomes and fibroblast growth factor receptor 3 (FGFR3) protein expression status of a large series (n = 45) of urothelial carcinoma of bladder patients aged 30 or younger, retrospectively. We identified an age gradient (an age of 25, 26 and 27 years), classified patients as ≤ 25 or >25, ≤ 26 or >26, ≤ 27 or >27 years, respectively, and compared variables including recurrence events and FGFR3 expression patterns between different groups. Patients aged 25 years or younger were less likely to experience tumor recurrence (p = 0.046), were more likely to develop smaller size tumors (p = 0.040) and expressed more proportion of negative pattern of FGFR3 protein (p = 0.036). Patients aged 25 years or younger were less likely to develop tumor recurrence and revealed more proportion of negative pattern of FGFR3 expression than those aged 26-30 years did. We identified patients aged 25 years or younger as the true "young" urothelial carcinoma patients, carrying distinct clinical outcomes and molecular tumorigenesis.