The Role of Biomarkers in the Management of Muscle-Invasive Bladder Cancer.

Muscle-invasive bladder cancer (MIBC) management is evolving beyond traditional clinicopathologic staging to include integration of molecular biomarkers. DNA damage repair gene alterations predict cisplatin sensitivity, while fibroblast growth factor receptor mutations identify candidates for targeted therapy. Transcriptomic subtypes reveal tumor phenotypes with variable treatment responses. Most significantly, circulating tumor DNA (ctDNA) enables dynamic disease monitoring, with postoperative ctDNA detection identifying high-risk patients who benefit from adjuvant immunotherapy while ctDNA-negative patients can safely avoid overtreatment. Despite promising advances, challenges including prospective validation, standardization, and accessibility limit widespread clinical adoption. This article examines current evidence and future directions for biomarker-driven MIBC management.