Detection of circulating tumor cells with epithelial-mesenchymal transition phenotype as critical surrogate biomarkers in patients with non-small cell lung cancer.

e22031 Background: Circulating tumor cells (CTC) have a crucial role in clinical outcome of patients. However, low counts of CTCs have been reported in patient with non-small cell lung cancer (NSCLC) by methods using EpCAM antigen expression. The loss of epithelial markers could therefore lead to an underestimation of CTCs with mesenchymal phenotype. Epithelial-mesenchymal transition (EMT) is considered as an essential process in the metastatic cascade and acquiring chemoresistance. The aim of this study is to investigate CTCs with mesenchymal phenotype as surrogate biomarkers by using the new telomerase-specific replication-selective adenovirus TelomeScan F35 (OBP-1101). Methods: Peripheral venous blood samples were obtained from 26 patients with resected NSCLC and 8 patients with advanced NSCLC before and after 1W of first-line chemotherapy. The viable human CTCs were visualized as GFP positive to count the CTCs by OBP-1101. Then triply labelled with fluorescent anti-vimentin, anti-EpCAM and anti-CD45 a...