[Preliminary Study on Detection of Circulating Tumor Cells in Lung Cancer by EGFR/Vimentin/Folic Acid Magnetic Sphere].

Background: Circulating tumor cells (CTC) play an important role in the screening and prognosis of lung cancer, but the low efficiency and specificity of CTC isolation obviously restrict its clinical application. The purpose of this study is to explore a new and efficient isolation method of CTC in patients with non-small cell lung cancer (NSCLC) in order to achieve the purpose of early diagnosis of NSCLC.

Methods: Three kinds of immunolipid magnetic spheres of epidermal growth factor receptor (EGFR), vimentin and folic acid (FA) were prepared by thin film method. After characterization, the sorting scheme of cell line was explored, the optimal sorting scheme of NSCLC CTC was constructed, and its clinical application value was studied.

Results: The average capture efficiency of EGFR, Vimentin and FA magnetic spheres used alone and in combination to lung cancer cell lines was 78%, 79%, 82% and 91%, respectively. In 60 patients with lung cancer, using 2 CTC per 7.5 mL blood as cutoff value, the positive rates of EGFR, Vimentin and FA magnets used alone and in combination were 65.0%, 33.3%, 93.3% and 100%, respectively. It was also found that the number of CTC detected by combined use of the three magnetic spheres was correlated with clinical stages (P<0.05).

Conclusions: The combination of three kinds of magnetic spheres can separate EGFR+, Vimentin+, FA+ expressed CTC, which is beneficial to the downstream analysis of CTC correlation. This study provides a new method to improve the efficiency of NSCLC CTC capture, and verifies that the captured CTC counting method can be used in the auxiliary diagnosis of lung cancer.