Perspective on Cancer Therapeutics Utilizing Analysis of Circulating Tumor Cells

Abstract

Various methods are available for cancer screening, and the methods are performed depending on the origin site of cancer. Among these methods, biopsy followed by medical imaging is the most common. After cancer progression is determined, an optimal treatment—such as surgery, chemotherapy, and/or radiation therapy—is selected. A new assay has been developed that detects circulating tumor cells (CTCs). Tracking changes in CTCs may reveal important tumoral sensitivity information or resistance patterns to specific regimens and prompt changes in therapy on a personalized basis. Characterization of CTCs at the DNA, RNA, and protein levels is important for gaining insight for clinical applications. A small number of CTCs can be analyzed to obtain genome information such as the progression of cancer including metastasis, even in a single cluster. Although many clinical studies, particularly CTC enumeration and detection of specific oncogene expression, have increased the success rate of diagnosis and predicting prognosis, there is no consensus regarding the technical approaches and various aspects of the methodology, making it difficult to standardize optimal methods for CTC analysis. However, ongoing technological advances are currently being achieved and large-scale clinical studies are being conducted. Applying CTC analysis in the clinic would be very useful for advancing diagnosis, prognosis prediction, and therapeutics.

Expression Profiling of Circulating Tumor Cells in Pancreatic Ductal Adenocarcinoma Patients: Biomarkers Predicting Overall Survival

“…Recently, the detection/isolation of circulating tumor cells (CTCs) in blood samples from cancer patients prompted high interest. CTCs, believed to be responsible for seeding and dissemination of cancer, originate from the primary tumor mass and spread in the peripheral circulation among immune cells and erythrocytes (6). In addition, CTCs are also able to aggregate forming clusters, termed circulating tumor microemboli, whose size and concentration have been found to influence the development of metastases.…”

The Crosstalk Between Immune Infiltration, Circulating Tumor Cells, and Metastasis in Pancreatic Cancer: Identification of HMGB3 From a Multiple Omics Analysis

“…In recent years, CTCs detected and isolated from blood samples of cancer patients have attracted great attention. CTCs are considered to be responsible for tumor metastasis, released from the primary tumor and spread in the peripheral blood circulation between immune cells and red blood cells ( Jeong et al, 2018 ). With the development of CTC detection and RNA-sequencing technology, it is gradually recognized that there is great heterogeneity among CTCs, and not all CTCs could survive in blood and consequently lead to distant metastasis.…”

Advancement of single-cell sequencing for clinical diagnosis and treatment of pancreatic cancer

“…Liquid biopsy is defined as the study of tumor biology from different blood sources. It has gained widespread adoption in the early diagnosis of solid tumors due to its advantages of simplicity and non-invasiveness, such as the detection of circulating tumor DNA (ctDNA) or circulating tumor cells (CTC) ( 27 ). Circulating tumor cells (CTCs) are shed from the tumor tissue and form distant metastases through circulation.…”