Establishment of a multi-targeted magnetic combined enrichment system for circulating tumor cells in gastric cancer and analysis of their genomic profiles

Background: This study aims to establish an efficient Circulating tumor cells (CTCs) multi-targeted magnetic combined sorting system for Gastric cancer (GC), while comparing it with tissue and circulating tumor DNA (ctDNA) samples to evaluate its feasibility and consistency for genomic profiling analysis. Method: Establish an efficient CTCs sorting system for GC targeting epithelial cell adhesion molecule, cell surface vimentin, and protein tyrosine kinase 7, and evaluate its physicochemical properties and cell capture efficiency. Assess the feasibility of tumor cell detection through animal experiments. Sixty-eight GC patients underwent CTCs detection. Clinical information was analyzed to evaluate the clinical utility of CTCs in the auxiliary diagnosis of GC. Next-generation sequencing was performed on GC tissue, CTCs, and ctDNA samples to assess the consistency of genetic mutations across different sample types. Results: The constructed CTCs sorting system exhibits excellent physicochemical properties, achieving a capture rate of 94.68%. Animal studies confirm a positive correlation between tumor cells count and tumor volume. The number of CTCs in the blood of GC patients is significantly correlated with tumor size, stage, and metastasis. The CTCs count in GC patients is significantly higher than in healthy individuals and high-risk groups for cancer, with diagnostic sensitivity and specificity of 97.29% and 97.73%, respectively. The mutation detection rate in CTCs samples was significantly higher than that in tissue and ctDNA samples. The concordance rate between CTCs and tissue mutations was 24.32%, while the concordance rate between CTCs and ctDNA mutations was 19.05%. Conclusion: This study successfully established a multi-target combined CTCs multi-targeted magnetic combined sorting system for GC. CTCs detection based on this system can be used for the auxiliary diagnosis of GC patients. Furthermore, compared to GC tissue and ctDNA samples, CTCs detection enables more comprehensive genomic profiling analysis and serves as an important supplement to GC genomic analysis.