Circulating tumor cells (CTC) play a crucial role in the natural history of several malignancies and, thus, are the subject of intense research efforts. This review summarizes the most contemporary literature data regarding detection of CTC and their impact on the oncological prognosis of patients with urothelial carcinoma of the bladder (UCB). Despite the availability of different methods for CTC detection and isolation in the peripheral blood, the standardized and Food and Drug Administration-approved CellSearch® assay is currently the most commonly used system for CTC detection. The majority of studies did not find any association between presence of CTC and clinicopathologic features. However, CTC have been demonstrated to represent a strong, independent predictor for unfavorable oncological outcomes in UCB. Since the peripheral blood is an easily accessible source, CTC represent a promising biomarker to effectively monitor early disease progression and therapy response in the near future. CTC hold the potential to individualize patient counseling regarding the optimal timing of radical surgery or bladder-sparing treatment as well as multimodal therapies.
