Role of the FGFR3 gene mutation status in predicting progression of non-muscle-invasive bladder cancer

A prospective study was conducted to assess the prognostic value of FGFR3 gene mutation status in patients with non-muscle invasive bladder cancer. A total of 265 patients were included in the study. FGFR3 gene mutations were found in 168 (63.4 %) cases. FGFR3 mutation rate was significantly higher in low-grade tumors (p = 0.00 004). With a median follow-up of 34 months hazard ratio of progression in FGFR3 mutant cases compared to FGFR3 wild type was 0.50 (95 % CI 0.17–1.49; p = 0.21). In the subgroup analysis, it was found that FGFR3 mutations in patients with T1 high grade tumors (n = 41) were associated with a significantly better prognosis: 3-year progression-free survival (PFS) in FGFR3 mutant cases (n = 17) was 100 % compared to 71.2 % (95 % CI 42.8–99.6 %) in the absence of mutations (n = 24). For other subgroups (Ta, T1 low grade) no statistically significant difference in PFS by FGFR3 mutation status was noted.