Circulating tumor cells in bladder cancer: A new horizon of liquid biopsy for precision medicine

Clinical management of bladder cancer (BC) patients offers several challenges such as poor outcome because of elevated recurrence rates and lack of response to chemotherapy [1]. So, there is a need of noninvasive prognostic and predictive tools able to allow risk category assessment and real-time supervision of drug response [2]. Recently, circulating tumor cells (CTCs) have been proposed as prognostic tool able to improve cancer patients' clinical management [3], [4], [5], [6]. CTCs detached from the primary tumor, enter the bloodstream and colonize distant organ, promoting cancer dissemination [7]. Emerging technologies are available to isolate CTC from patient's blood to provide a "liquid biopsy". Such a tool provides a molecular picture of the metastatic disease, useful to assess the cause of drug resistance onset [3, 6, 8], [9], [10], [11], [12], [13], [14]. CTC are very scarce in the blood, so robust methods are still needed for their routine use in laboratory practice [3, 11]. Several technologies have been developed in the last few years [11, 12] and several studies have been performed on the potential use of CTCs in bladder cancer patient clinical management.