Clinical application of circulating tumor cells in gastric cancer: advances and prospects

Abstract

Malignant tumors seriously threat the health of the Chinese population. Circulating tumor cell (CTC), as molecular markers in liquid biopsy, have the advantage of being non-invasive and longitudinal monitoring of tumor progression and efficacy. In vitro CTC enrichment detection methods are divided into two types: based on molecular characteristics and based on physical characteristics. In recent years, a series of comprehensive CTC enrichment methods targeting different molecular characteristics have been developed, as well as the use of subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) for enrichment detection of gastric cancer CTC. Microfluidic technology can separate and enrich CTC on the same chip based on their molecular and physical characteristics simultaneously, helping to achieve more efficient and sensitive CTC enrichment detection. Compared with the in vitro CTC enrichment platform, the in vivo CTC enrichment platform has higher capture efficiency and detection sensitivity, but it is an invasive examination, and the impact on patients still needs further study. High CTC level is closely related to the disease control rate after gastric cancer chemotherapy and is an independent predictor of poor prognosis in gastric cancer patients. Among non-metastatic malignancies, increased CTC counts after surgery in patients with esophageal cancer and colorectal cancer are strongly associated with worse overall survival. Since CTC are highly heterogeneous, changes in CTC can be longitudinally monitored to provide a reference for the treatment of malignant tumors. Research on gastric cancer has shown that the positivity rate, size of circulating tumor microemboli (CTM) and gene expression level of CTC are closely related to the ability of invasion, metastasis, drug resistance and prognosis. The dynamic metastasis process and pattern of CTC play an important role in tumor metastasis. For the detection of CTC, it is necessary to establish unified standards and verification methods, and develop multi-omics research technology.

Keywords

• |circulating tumor cell|gastric cancer|therapeutical resistance monitoring|prognostic monitoring|targeted therapy