Circulating Tumor Cells in the Adenocarcinoma of the Esophagus

Abstract

Circulating tumor cells (CTCs) are elements of indisputable significance as they seem to be responsible for the onset of metastasis. Despite this, research into CTCs and their clinical application have been hindered by their rarity and heterogeneity at the molecular and cellular level, and also by a lack of technical standardization. Esophageal adenocarcinoma (EAC) is a highly aggressive cancer that is often diagnosed at an advanced stage. Its incidence has increased so much in recent years that new diagnostic, prognostic and predictive biomarkers are urgently needed. Preliminary findings suggest that CTCs could represent an effective, non-invasive, real-time assessable biomarker in all stages of EAC. This review provides an overview of EAC and CTC characteristics and reports the main research results obtained on CTCs in this setting. The need to carry out further basic and translational research in this area to confirm the clinical usefulness of CTCs and to provide oncologists with a tool to improve therapeutic strategies for EAC patients was herein highlighted.

Serum glycoprotein biomarker validation for esophageal adenocarcinoma and application to Barrett’s surveillance

“…Over the years, several studies have been carried out to identify circulatory biomarker candidates to diagnose BEdysplasia-EAC disease spectrum (19,27). These studies have explored genetic alterations in cell free circulating DNA (28), serum miRNA changes (29), circulatory tumor cells (30), glycan profile alteration in serum (31,32), circulatory autoantibodies (against cancer antigens) (33), volatile organic compounds found in breath analysis (34), metabolic changes in urine (35), and a panel of serum proteins (36) as promising diagnostic biomarker candidates for BE and/or EAC. However, none of these biomarker candidates have progressed to from bench to bedside, likely due to the lack of subsequent validation studies in large independent cohort of patients.…”

Predictive Value of Circulating Tumor Cells for Evaluating Short- and Long-Term Efficacy of Chemotherapy for Breast Cancer

“…Generally speaking, more than 2 CTCs per 7.5 ml of blood are present in 60% of patients with MBC [ 32 ]. The measurement of CTCs before and after surgical treatment for esophageal squamous cancer (EAC) is of great help in predicting tumor recurrence [ 33 ]. Chemotherapy is reported to be an effective way to kill CTCs in the blood of cancer patients, which is superior to tumor surgery and radiation therapy [ 34 ].…”

“…In the present study, we also analyzed the correlation between CTC counts and clinicopathological features of BC patients. As a preoperative staging factor in EAC, the CTC count is considered to be independent of tumor-related indicators, such as tumor stage and grade, histological subtype, and lymph node invasion [ 33 ]. However, in patients with BC, there was a correlation between CTC counts and TNM staging, tumor size, LNM, ki-67, molecular classification, and endocrine therapy.…”

Highlighting the uniqueness in dielectrophoretic enrichment of circulating tumor cells

“…This diversity is further enhanced by the epithelial-mesenchymal transition (EMT) in which cancer cells with a polarized epithelial phenotype switch to a mesenchymal or fibroblastoid cellular phenotype [56]. Consequently, CTCs gradually lose their epithelial characteristics defined by the EpCAM and various cytokeratins (CKs) surface markers and consequently their chances of being detected using EpCAM-based methods are significantly reduced [57,58]. The variable molecular, genomic and functional characteristics of the CTCs that differentiate them one from another and from the primary tumor obstruct the optimization of the CTC isolation process [59].…”