Abstract 3786: Multicenter evaluation of technology platforms for the enumeration of circulating tumor cells
Authors: Bender Sebastian , Lütke-Eversloh Merlin V. , Neves Rui P. , Stoecklein NNikolas H. , Terstappen Leon W. , Baggiani Barbara , Neumann Martin H. , Krahn Thomas , Pantel Klaus , Schlange Thomas , Zeune Leonie L. 
Published: July 2017

Abstract
Metastasis represents the deadliest feature of cancer, which is fueled by circulating tumor cells (CTCs) being released into the bloodstream from the primary tumor. In addition to the clinical value of CTC enumeration for metastatic risk assessment, CTCs are considered to be a minimally invasive source for studying the molecular and genetic features of the disease as well as response to anticancer therapy. Given the molecular heterogeneity of CTCs, which includes loss of epithelial surface marker expression, several microfluidic and filtration technology platforms were developed to overcome the limitations of surface marker dependent CTC enrichment. Here we describe the efforts of the Innovative Medicines Initiative (IMI) consortium CANCER-ID (www.cancer-id.eu), which represents a joint undertaking of experts from academia and pharmaceutical industry, in generating comparative data using different CTC enrichment platforms in a multicenter ring trial.
To address clinically relevant subtypes of Non-Small Cell Lung Cancer (NSCLC), different NSCLC cell lines were profiled for genetic aberrations (mutations and copy number aberrations), expression of epithelial markers (epithelial cell adhesion molecule (EPCAM) and cytokeratins) as well as cell size. Cell lines were selected to generate spike-in samples using blood of healthy volunteers with informed consent in a centralized way. Analysis was performed by at least three CANCER-ID partners using different CTC enrichment technologies including the Siemens filtration device, the Parsortix PR1, VyCap filtration and the CellSearch system.
To ensure quality and comparability of results, CANCER-ID partners established standard operation procedures (SOPs) for pre-analytic sample handling including sample fixation, storage and shipment. Special attention was paid on the development of SOPs for the actual CTC enrichment procedure and the integration of downstream applications including single cell isolation by DEPArray™ followed by Ampli1™ WGA and molecular and genetic characterization of isolated cells. Epitope-independent enrichment by filtration or microfluidic devices was evaluated by using NSCLC cells with substantially different cell size. In addition, comparative data on spike-in samples was generated using the EPCAM-expression dependent CellSearch system, which failed to detect EPCAM-negative tumor cells.
In conclusion, the evaluation of different CTC enrichment technologies and the integration of workflows for downstream analysis of single cells blaze the trail for the next phase of IMI’s CANCER-ID, which includes the analysis of real-life NSCLC patient material.
This work is supported by IMI JU & EFPIA (grant no. 115749).
Citation Format: Sebastian Bender, Merlin V. Lütke-Eversloh, Rui P. Neves, NNikolas H. Stoecklein, Leon W. Terstappen, Barbara Baggiani, Martin H. Neumann, Thomas Krahn, Klaus Pantel, Thomas Schlange, Leonie L. Zeune. Multicenter evaluation of technology platforms for the enumeration of circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3786. doi:10.1158/1538-7445.AM2017-3786