Int J Biol Sci 2022; 18(8):3251-3265. doi:10.7150/ijbs.71768 This issue


Circulating tumor cells in the early detection of human cancers

Zixin Feng1, Junyu Wu1, Yuanjun Lu1, Yau-Tuen Chan1, Cheng Zhang1, Di Wang2, Dan Luo3, Yuan Huang3, Yibin Feng1✉, Ning Wang1✉

1. School of Chinese Medicine, The University of Hong Kong, Hong Kong S.A.R, P.R. China
2. School of Life Science, Jilin University, Jilin, P.R. China
3. Cellomics International Limited, Hong Kong S.A.R., P.R. China

This is an open access article distributed under the terms of the Creative Commons Attribution License ( See for full terms and conditions.
Feng Z, Wu J, Lu Y, Chan YT, Zhang C, Wang D, Luo D, Huang Y, Feng Y, Wang N. Circulating tumor cells in the early detection of human cancers. Int J Biol Sci 2022; 18(8):3251-3265. doi:10.7150/ijbs.71768. Available from

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Graphic abstract

Cancer is a severe disease with high morbidity and mortality globally. Thus, early detection is emerging as an important topic in modern oncology. Although the strategies for early detection have developed rapidly in recent decades, they remain challenging due to the subtle symptoms in the initial stage of the primary tumor. Currently, tumor biomarkers, imaging, and specific screening tests are widely used in various cancer types; however, each method has limitations. The harms are even overweight against the benefits in some cases. Therefore, early detection approaches should be improved urgently. Liquid biopsy, for now, is a convenient and non-invasive way compared to the traditional tissue biopsy in screening and early diagnosis. Circulating tumor cells (CTCs) are vital in liquid biopsy and play a central role in tumor dissemination and metastases. They have promising potential as cancer biomarkers in early detection. This review updates the knowledge of the biology of CTC; it also highlights the CTC enrichment technologies and their applications in the early detection of several human cancers.

Keywords: Circulating tumor cell (CTC), Early detection, Liquid biopsy, Human cancers, Cancer metastasis