In vivo isolation of circulating tumor cells in non-small cell lung cancer (NSCLC) patients by a medical device.

Abstract

10536 Background: Currently, circulating tumor cells (CTCs) are isolated in vitro from small limited volumes of blood samples. Furthermore, CTC results for NSCLC as a prognostic and stratification biomarker are scarce. The aim of the study was to assess a functionalized and structured medical wire (FSMW) for in vivo isolation of CTCs directly from the blood of NSCLC patients, and to compare it to the Cell Search method. Methods: The device was inserted in a cubital vein through a standard cannula for thirty minutes. The interaction of target CTCs with the FSMW was mediated by an antibody directed against the epithelial cell adhesion molecule (EpCAM). To confirm the CTCs binding to the wire, the immunohistochemical staining against EpCAM as well as CD45 for negative cell selection was performed. There were 72 applications of the wire in 48 stage I-IIIB NSCLC patients (12 double applications) and 12 non cancer patients. Enumeration data was available for 34 NSCLC patients and 8 non cancer patients. For 34 patients, samples were also tested in the Cell Search system. Results: The device was well tolerated in all 72 applications without side effects. We obtained in vivo isolation of CTCs in 32 of 34 NSCLC patients (94.1%) with a median (range) of 13 (0-300) CTCs. The sensitivity was similar for early and late stage NSCLC patients. In the non-cancer patients, no CTCs were detected (100 % specificity). In 2 of 34 samples (5.8%), CTCs were detected by the Cell Search method. In all matched pairs, the FSMW detected the same number or more CTCs compared to the Cell Search method. Conclusions: Whilst well tolerated without side effects, the CTC detection rate of the FSMW in NSCLC patients was >90%. In contrast, <10% detection was obtained using the Cell Search analysis. No CTCs were detected in non-cancer patients. This proof of concept study may have important clinical implications, as the implementation of the device into clinical practice may improve early detection, prognosis and therapy monitoring of NSCLC patients. The method may also allow the molecular analysis of the CTCs, with the possibility of establishing more personalized treatment regiments.