Sorting and gene mutation verification of circulating tumor cells of lung cancer with epidermal growth factor receptor peptide lipid magnetic spheres

BACKGROUND: This study aimed to identify an efficient, simple, and specific method of detecting mutations in the epidermal growth factor receptor (EGFR) gene in isolated lung cancer circulating tumor cells (CTCs) and to improve the ability to obtain tumor tissue clinically. METHODS: EGFR peptide lipid magnetic spheres (EG‐P‐LMB) were prepared by reverse evaporation, and characterization and cell capture efficiency assessed. The peripheral blood samples of 30 lung cancer patients were isolated and identified with the EG‐P‐LMB using 20 healthy volunteers as controls. Finally, the isolated CTCs were tested for EGFR gene mutations, and the tissue samples selected for comparison. RESULTS: The prepared magnetic spheres had a smaller particle size and higher stability according to the particle size potential test. Their morphology was homogeneous by atomic force observation, and the UV test showed that there were peptides on the surface. The separation efficiency of EG‐P‐LMB was greater than 90% in PBS and greater than 80% in the blood simulation system. Compared with the tissue sample results, the positive rate of EGFR gene mutations was 94%. The CTC test results of 27 patients were consistent with the tissue test results of the corresponding patients, and the consistency with the tissue comparison test results was 90% (27/30). CONCLUSIONS: EG‐P‐LMB can effectively capture CTCs in the peripheral blood of patients with lung cancer. CTC detection can accurately identify mutations in the EGFR gene and improve the ability to obtain tumor tissue in clinical practice. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: EG‐P‐LMB can effectively capture CTCs in the peripheral blood of patients with lung cancer. CTC detection can accurately identify mutations in the EGFR gene and improve the ability to obtain tumor tissue in clinical practice. WHAT THIS STUDY ADDS: This study added EGFR peptide lipid magnetic spheres to capture CTCs in the blood. Genetic testing was performed and compared with tissues. It solves the problem of clinically difficult tumor tissue sampling.