  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.
