Circulating Tumor Cells in Cancer Diagnostics and Prognostics by Single-Molecule and Single-Cell Characterization

Circulating tumor cells (CTCs) represent an interesting source of biomarkers for diagnosis, prognosis, and the prediction of cancer recurrence, yet while they are extensively studied in oncobiology research, their diagnostic utility has not yet been demonstrated and validated. Their scarcity in human biological fluids impedes the identification of dangerous CTC subpopulations that may promote metastatic dissemination. In this Perspective, we discuss promising techniques that could be used for the identification of these metastatic cells. We first describe methods for isolating patient-derived CTCs and then the use of 3D biomimetic matrixes in their amplification and analysis, followed by methods for further CTC analyses at the single-cell and single-molecule levels. Finally, we discuss how the elucidation of mechanical and morphological properties using techniques such as atomic force microscopy and molecular biomarker identification using nanopore-based detection could be combined in the future to provide patients and their healthcare providers with a more accurate diagnosis.

Automated summary

Circulating tumor cells (CTCs) have potential as biomarkers for diagnosing, predicting and monitoring cancer, but their diagnostic utility is yet to be proven. The scarcity of CTCs in biological fluids makes it difficult to identify dangerous subpopulations that could lead to metastasis. This Perspective discusses promising techniques for identifying metastatic cells, including isolating patient-derived CTCs, using 3D biomimetic matrixes for their analysis, and analyzing CTCs at the single-cell and single-molecule levels. The article also explores the combination of mechanical and morphological analysis methods with biomarker identification techniques for more accurate diagnosis.