Prognostic significance of the FAN score in patients with advanced urothelial carcinoma treated with enfortumab vedotin monotherapy.

OBJECTIVE: To evaluate the prognostic significance of the Fib-4 index, ALBI and NLR (FAN) score, a composite score comprising the fibrosis-4 index, albumin-bilirubin score, and neutrophil-to-lymphocyte ratio, in patients with advanced urothelial carcinoma treated with enfortumab vedotin (EV) monotherapy. METHODS: This multicenter retrospective study included 164 patients with advanced urothelial carcinoma who received EV monotherapy following prior systemic therapy. Patients were classified into three groups (0, 1, and 2-3) based on the FAN score, and progression-free, cancer-specific, and overall survival (OS) outcomes were evaluated. RESULTS: The proportion of patients with FAN scores of 0, 1, and 2-3 were 26.8% (n = 44), 40.2% (n = 66), and 32.9% (n = 54), respectively. Median progression-free survival (PFS) was 8.1, 5.7, and 3.8 months across FAN score groups. A significant difference was observed between the FAN 0 and 2-3 groups (Holm-adjusted P = .025). Median cancer-specific survival (CSS) was 17.5, 12.2, and 7.2 months and differed significantly across groups (Holm-adjusted P = .012). OS showed a similar significant decline (Holm-adjusted P = .013). Multivariable analysis confirmed the FAN score as an independent prognostic factor for OS, CSS, and PFS. Furthermore, adding the FAN score to a model comprising conventional clinical factors improved prognostic accuracy for both CSS and OS (ΔC-index for CSS = 0.067, bootstrap P < .001; ΔC-index for OS = 0.057, bootstrap P < .001). CONCLUSIONS: The FAN score is a simple and clinically useful prognostic tool that may improve risk stratification in patients receiving EV monotherapy for advanced urothelial carcinoma.