Current techniques and future advance of microfluidic devices for circulating tumor cells

Circulating tumor cells (CTCs), escaped from solid tumor to peripheral blood, are responsible for tumor metastasis and closely relevant to cancer progression. As one of the targets of "liquid biopsy", CTCs play an important role in noninvasive tumor diagnosis. In the past decades, various microfluidic devices have been developed to efficiently isolate and accurately numerate CTCs. However, simply enumeration of CTCs can't satisfy the requirements of downstream analysis and clinical application of CTCs. Recently, new microfluidic chips have demonstrated superior advantages in extracting more information from CTCs. In this minireview, we will summarize the classical microfluidic devices for isolating and detecting CTCs, and discuss recent advances of microfluidic chip for in-depth research of CTCs, such as heterogeneity, phenotype and genotype analysis, ex vivo expansion as well as in vivo isolation et al. Finally, we will predict future research for developing next-generation of microfluidic chip to satisfy clinical demand.