Clinical Relevance of Circulating Tumor Cells in Esophageal Cancer Detected by a Combined MACS Enrichment Method

Abstract

Introduction. Current modalities to predict tumor recurrence and survival in esophageal cancer are insufficient. Even in lymph node-negative patients, a locoregional and distant relapse is common. Hence, more precise staging methods are needed. So far, only the CellSearch system was used to detect circulating tumor cells (CTC) with clinical relevance in esophageal cancer patients. Studies analyzing different CTC detection assays using advanced enrichment techniques to potentially increase the sensitivity are missing. Methods. In this single-center, prospective study, peripheral blood samples from 90 esophageal cancer patients were obtained preoperatively and analyzed for the presence of CTCs by Magnetic Cell Separation (MACS) enrichment (combined anti-cytokeratin and anti-epithelial cell adhesion molecules (EpCAM)), with subsequent immunocytochemical staining. Data were correlated with clinicopathological parameters and patient outcomes. Results. CTCs were detected in 25.6% (23/90) of the patients by combined cytokeratin/EpCAM enrichment (0-150 CTCs/7.5 mL). No significant correlation between histopathological parameters and CTC detection was found. Survival analysis revealed that the presence of more than two CTCs correlated with significantly shorter overall survival (OS) and progression-free survival (PFS). Conclusion. With the use of cytokeratin as an additional enrichment target, the CTC detection rate in esophageal cancer patients can be elevated and displays the heterogeneity of cytokeratin (CK) and EpCAM expression. The presence of >2CTCs correlated with a shorter relapse-free and overall survival in a univariate analysis, but not in a multivariate setting. Moreover, our results suggest that the CK7/8 + /EpCAM + or CK7/8 + /EpCAM − CTC subtype does not lead to an advanced tumor staging tool in non-metastatic esophageal cancer (EC) patients.

The Diagnostic and Prognostic Value of a Liquid Biopsy for Esophageal Cancer: A Systematic Review and Meta-Analysis

“…Eleven studies were enrolled for OS analysis, with a total of 854 EC patients [ 13 , 25 , 26 , 27 , 29 , 32 , 54 , 75 , 82 , 83 , 84 , 85 ]. In this cohort, the average age was 63.6 years (61.5–66) and the median CTC positivity rate was 46.4% (18.0–79.7).…”

Detection of Epithelial Cell Adhesion Molecule in Feline Normal and Tumor Cell Lines and Tissues With Selected Commercial Anti-human EpCAM Antibodies

“…EpCAM can be downregulated during epithelial-to-mesenchymal transition, which can precede transmigration of tumor cells from interstitial tissues to the intravascular space, limiting CTC detection. Therefore, methods to capture CTCs using antibody cocktails against various markers have been developed ( 3 , 17 , 34 ). Evaluation of antibodies against other epithelial or tumor-based markers, such as Mucin 1 and epidermal growth factor receptor ( 35 , 36 ), for detection of epithelial-derived CTCs in cats would be worthwhile.…”

“…The fact that EpCAM expression is limited to epithelial cells makes it a good candidate for use as an epithelial-derived CTC marker, because human blood leukocytes typically lack EpCAM expression ( 14 ). Numerous studies have shown that EpCAM-positive cells can be detected in the circulation of human patients with various carcinomas and those patients with high numbers of CTCs have lower overall survival ( 4 , 5 , 15 – 17 ). Indeed, analyzers have been built for the specific purpose of detecting EpCAM-positive CTCs (e.g., CellSearch®) ( 5 , 18 ).…”

Comparative Analysis of Blood and Bone Marrow for the Detection of Circulating and Disseminated Tumor Cells and Their Prognostic and Predictive Value in Esophageal Cancer Patients

“…With this technique, we were able to achieve detection rates of 36.5% in the blood and 31.1% in the bone marrow. This technique is validly more sensitive than surface antigen-based enrichment procedures, which yielded detection rates of 2 to 25.6% for CTC, and up to 17.1% for DTC [ 38 , 39 , 40 , 41 ].…”

“…The major limitation of immunomagnetic enumeration methods (e.g., using EpCAM as a surface marker) is that only a subset of CTC expressing this marker is detected, because it has been shown that CTC may have undergone EMT, by which the cells become motile, disseminate in the body and downregulate EpCAM expression [ 42 , 43 ]. Thus, strategies combining the analysis of more than one epithelial marker (e.g., cytokeratin and EpCAM) have been established providing a more reliable detection of CTC and DTC thereby increasing the detection rates also in EC patients [ 41 ]. Importantly, CTC and DTC, which have undergone EMT and exhibit a more mesenchymal phenotype, might be a cellular subgroup of high clinical relevance, because these cells seem to be characterized by a particularly aggressive metastatic potential along with drug resistance [ 44 ].…”