Detection of Circulating Tumor Cells Using a Novel Immunomagnetic Bead Method in Lung Cancer Patients

Circulating tumor cells (CTCs) are detectable in peripheral blood of metastatic lung cancer patients. In this article, we evaluate a new CTC separation method based on a combination of anti-EpCAM and immunomagnetic beads with the aim to detect CTCs more conveniently and specifically.

Lung cancer cells were magnetically labeled by anti-EpCAM magnetic beads, and subsequently captured by magnetic separation using our novel device. Isolated lung cancer cells were identified by pathomorphological by hematoxylin-eosin staining protocol. The system was used to detect CTCs in 2 ml blood. Blood samples of healthy donors spiked with lung cancer cell line A549 cells were used to determine the sensitivity and specificity of the method. Prevalence of CTCs was examined in samples from 56 patients with lung cancer.

Regression analysis of number of recovered versus spiked A549 cells yielded a coefficient of determination of R(2) = 0.996 (P < 0.001). The average recovery was 68% or more at each spiking level. The coefficient of variation increased as the number of spiked cells decreased, ranging from 6.4% (1,000-cell spike) to 18.4% (50-cell spike). Forty-nine of the fifty-six patients (87.5%) were found to have CTCs in peripheral blood. None of the 2 ml peripheral blood samples of the 20 healthy subjects analyzed were found to have CTCs.

This novel turbulence device provides a new tool allowing for feasible and specific detection of CTCs in lung cancer patients. It is likely clinically useful in diagnosis and monitoring of lung cancer and may have a role in clinical decision making.