About this Research Topic
Thirty per cent of cancer patients are prescribed the wrong therapy. The major reason for treatment failures is oncologists‘ inability to monitor the evolution of cancer in patients and adapt treatment accordingly. Moreover, cancer mortality largely occur because of metastasis, however, understanding of the metastatic cascade and mechanisms underlying this complex set of events remain poorly understood. Cancer cells invade the surrounding tissue of primary or metastatic tumors, intravasate into lymphatic and blood vessels, disseminate to distant tissues, extravasate by adapting to the new microenvironment, and colonize these tissues. Because dissemination mostly happen through the blood, circulating tumor cells (CTCs) are of paramount importance and one of the most promising areas of oncology research. CTCs might serve as “liquid biopsy” as a better way to diagnose cancer patients compared to painful biopsies of the primary tumor, and to better reflect cancer progression and monitoring in the patient: evaluation of CTCs may enable sensitive monitoring of treatment efficacy and guide drug selection, even in adjuvant settings where no tools exist today.
The isolation, characterization, and interrogation of CTCs are hampered by their rarity and heterogeneity, either inherited from respective primary or metastatic tumors or as a result of CTC evolution in blood by genetic/epigenetic progression that may or may not lead to fully metastatic-competent CTCs. Significant technical challenges in the field also persist in regard to identifying and interrogating CTC heterogeneity, assessing CTC biomarkers of clinical utility, and comprehensively capturing these fragile cells (usually, a ratio of one CTC per 106 leukocytes and 109 erythrocytes in one milliliter of blood). Finally, many studies have reported the clinical impact of enumerating CTCs, considering that CTC testing is being employed in over 300 clinical trials worldwide. However, much of the CTC biology and comprehensive characterization of CTCs/CTC subsets needs to be discovered, and many scientific/technical challenges must be overcome before their clinical promise as biomarkers and targets for improved therapies can be fulfilled.
The objective of this Research Topic is to publish latest findings in CTC research and clinical implementation. Contributions outlining CTC discoveries in biological and clinical settings, CTC theoretical and pre-clinical models, CTC technologies, platforms and methods for their detection, and clinical findings applying CTC concepts, are welcome.
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