Research on the biophysical properties of circulating tumor cells

This article reviews the biophysical properties of circulating tumor cells (CTCs) and their significance in tumor metastasis and liquid biopsy. CTCs are tumor cells that have shed from solid tumors or metastatic foci and entered the bloodstream, possessing various biological markers. They may be cleared by the immune system, enter a dormant state, or form clusters to facilitate metastasis. The physical properties of CTCs, including cell size, density, rigidity, and dielectric properties, differ from normal blood cells, providing a theoretical basis for separation and detection. The biological characteristics of CTCs include epithelial cell properties, expression of specific surface marker proteins, and the characteristics of epithelial-mesenchymal transition, which are crucial for the aggressiveness and metastatic potential of tumors. The development of CTC detection technologies, such as the Cell Search system, has been clinically applied, but the heterogeneity of tumor cells remains a major challenge in research. The development of composite separation technologies that combine various properties of CTCs is expected to improve the sensitivity, specificity, and efficiency of CTC detection, thereby playing an important role in the personalized treatment and prognostic assessment of tumors.