In the present review, we describe three hot topics in cancer research such as circulating
tumor cells, exosomes, and 3D environment models. The first section is dedicated to
microfluidic platforms for detecting circulating tumor cells, including both affinity-based
methods that take advantage of antibodies and aptamers, and “label-free” approaches, exploiting
cancer cells physical features and, more recently, abnormal cancer metabolism. In
the second section, we briefly describe the biology of exosomes and their role in cancer, as
well as conventional techniques for their isolation and innovative microfluidic platforms. In
the third section, the importance of tumor microenvironment is highlighted, along with techniques
for modeling it in vitro. Finally, we discuss limitations of two-dimensional monolayer
methods and describe advantages and disadvantages of different three-dimensional tumor
systems for cell-cell interaction analysis and their potential applications in cancer management.
EMT-Associated Heterogeneity in Circulating Tumor Cells: Sticky Friends on the Road to Metastasis