FGFR3 Mutations in Urothelial Carcinoma: A Single-Center Study Using Next-Generation Sequencing.

Background: Mutations of fibroblast growth factor receptor 3 ( FGFR3 ) are associated with urothelial carcinoma (UC) oncogenesis and are considered an important therapeutic target. Therefore, we evaluated the FGFR3 mutation rate and its clinical significance in urothelial carcinoma (UC) using next-generation sequencing. Methods: A total of 123 patients with UC who were treated at Chonnam National University Hospital (Gwang-ju, Korea) from January 2018 to December 2020 were enrolled. We performed NGS using the Oncomine panel with tumor specimens and blood samples corresponding to each specimen. We analyzed the FGFR3 mutation results according to the type of UC and the effects on early recurrence and progression. Results: The mean age of the patients was 71.39 ± 9.33 years, and 103 patients (83.7%) were male. Overall, the FGFR3 mutation rate was 30.1% (37 patients). The FGFR3 mutation rate was the highest in the non-muscle-invasive bladder cancer (NMIBC) group (45.1%), followed by the muscle-invasive bladder cancer (22.7%) and upper tract UC (UTUC) (14.3%) groups. Patients with FGFR3 mutations had a significantly lower disease stage ( p = 0.019) but a high-risk of NMIBC ( p < 0.001). Conclusions: Our results revealed that FGFR3 mutations were more prevalent in patients with NMIBC and lower stage UC and associated with a high-risk of NMIBC. Large multicenter studies are needed to clarify the clinical significance of FGFR3 mutations in UC.