Isolation and Characterization of Circulating Tumor Cells
Circulating tumor cells (CTCs) are tumor cells shed into the peripheral blood of cancer patients. The increasing number of treatment options for patients with metastatic carcinomas has created a concomitant need for new methods to establish which therapy will be effective and to monitor their use. Detection and characterization of CTCs is important not only to guide therapy, but also to increase our fundamental understanding of tumor progression and the formation of distant metastasis in which CTCs play a crucial role. However, identification of CTCs is quite challenging and different definitions lead to a large variation of CTC counts that will have different clinical implications. Here we will review the challenges in defining a CTC and data that have been obtained using CTCs in clinical studies emphasizing their importance as a prognostic and predictive biomarker. Furthermore, we summarize reported microfluidic platforms for CTC isolation, enumeration, and characterization developed to overcome technical challenges with current CTC detection platforms.