Circulating biomarkers to guide systemic therapy for urothelial carcinoma

There are very few biomarkers used to diagnose bladder cancer and no clinically approved biomarkers for prediction or prognostication of this disease. All currently available biomarkers are based on urine tests, and thus, they may not be applicable to patients with extravesical tumors. Biopsy of metastatic sites requires an invasive procedure, whereas serum-based markers, which can be easily obtained and serially measured, thus have obvious merit. These deficiencies may be overcome with advances in genome sequencing, identification of circulating tumor cells, and RNA-, protein-, and DNA-based biomarkers. Here, progress in circulating biomarkers in both superficial and invasive bladder cancer is described.