Enumeration and Molecular Characterization of Tumor Cells in Lung Cancer Patients Using a Novel <i>In Vivo</i> Device for Capturing Circulating Tumor Cells

TLDR

Low yield of circulating tumor cells limits their use as liquid biopsies, but in vivo isolation overcomes volume constraints and may enable clinical decision making. The study aims to evaluate a novel in vivo device, the GILUPI CellCollector, for isolating circulating tumor cells from peripheral blood. The GILUPI CellCollector captures CTCs in vivo from peripheral blood, bypassing the small sample volume limitation of conventional in vitro methods. In 50 lung cancer patients, the in vivo CellCollector detected CTCs in 58% of 185 applications (median 5 cells), outperforming the CellSearch system (27% detection), and CTC counts decreased with treatment response while KRAS/EGFR mutations were identified in captured cells and matched primary tumors. Published in Clinical Cancer Research, 22(9):2197–206; ©2015 AACR.

Abstract

The use of circulating tumor cells (CTC) as "liquid biopsy" is limited by the very low yield of CTCs available for subsequent analyses. Most in vitro approaches rely on small sample volumes (5-10 mL).Here, we used a novel approach, the GILUPI CellCollector, which enables an in vivo isolation of CTCs from peripheral blood. In total, 50 lung cancer patients were screened in two subsequent device applications before and after therapy (n = 185 applications).By in vivo isolation, 58% (108/185) of the patients were positive for ≥1 CTC (median, 5 CTCs; range, 1-56 cells) as compared with 27% (23/84; range, 1-300 cells) using the FDA-cleared CellSearch system. Furthermore, we could show that treatment response during therapy was associated with significant decreases in CTC counts (P = 0.001). By dPCR, mutations in the KRAS and EGFR genes relevant for treatment decisions could be detected in CTCs captured by in vivo isolation and confirmed in the primary tumors of the same patients.In vivo isolation of CTCs overcomes blood volume limitations of other approaches, which might help to implement CTC-based "liquid biopsies" into clinical decision making. Clin Cancer Res; 22(9); 2197-206. ©2015 AACR.