The Utility of Circulating Tumour Cells and Plasma microRNA Detection to Predict the Response to Treatment in Patients With Esophageal Adenocarcinoma

Recently, different groups have discovered that miRNAs can be detected in body fluids such as plasma, serum or saliva. These cell-free miRNAs are secreted by cells under different forms. Levels of these circulating miRNAs (circ miRNA), like tissue miRNA, were closely related to pathologies and could be used as diagnostic or prognostic tools for several pathologies, including cancer. Furthermore, a recent report showed that circ miRNAs released by tumor cells have the ability to transfer their metastatic potential to nonmetastatic cells. The detection and analysis of circulating miRNA represent a new step towards non-invasive diagnostic screening and early cancer detection.

Circulating tumor cells also hold promise as biological markers, which can be assessed noninvasively. As more than 90% of cancer deaths are associated with metastasis, it is crucial to understand the mechanisms of dissemination of cancer cells. During the past decade, a multitude of techniques have been developed to track down and to characterize CTC. Clinical studies in various cancers reveal the potential of CTC as prognostic and predictive markers. The characterization of CTC will help to design personalized treatment to eradicate the sub-clones of the primary tumour, which give rise to metastasis. Also, the numbers of CTC in patient blood can be followed to monitor the efficacy of the neoadjuvant treatment.

Most of the research in esophageal cancer has been done on squamous cell cancer as this is the dominant cell type worldwide. However, beginning the in 1980s Esophageal Adenocarcinoma (EAC) has increased in frequency such that it now represents 80% of esophageal cancer in North America and Europe. There is an urgent need to develop new techniques and diagnostic tests to combat EAC. By combining circ miRNA and CTC, we not only combine 2 promising clinical biomarkers, we will also be able to access new data that will complement tissue biopsy data. Furthermore, by acquiring a blood sample during various time points of patient treatment, we will be able to create a dynamic CTC and circ miRNA profile.