Relevance of Circulating Tumor Cells as Predictive Markers for Cancer Incidence and Relapse

Abstract

Shedding of cancer cells from the primary site or undetectable bone marrow region into the circulatory system, resulting in clinically overt metastasis or dissemination, is the hallmark of unfavorable invasive cancers. The shed cells remain in circulation until they extravasate to form a secondary metastatic lesion or undergo anoikis. The circulating tumor cells (CTCs) found as single cells or clusters carry a plethora of information, are acknowledged as potential biomarkers for predicting cancer prognosis and cancer progression, and are supposed to play key roles in determining tailored therapies for advanced diseases. With the advent of novel technologies that allow the precise isolation of CTCs, more and more clinical trials are focusing on the prognostic and predictive potential of CTCs. In this review, we summarize the role of CTCs as a predictive marker for cancer incidence, relapse, and response to therapy.

Advances in novel strategies for isolation, characterization, and analysis of CTCs and ctDNA

“…Whole genome amplification (WGA) allows for single-cell molecular profiling to analyze the differences in gene activation at various disease stages, thereby guiding therapy decision-making. 146,184 WGA is performed using three main techniques: First, PCR amplification, which includes long and accurate PCR (LA-PCR), primer extension preamplification PCR (PEP-PCR), degenerate oligonucleotide primer PCR (DOP-PCR), tagged random primer PCR (T-PCR), ligation-mediated PCR (LM-PCR), and interspersed repetitive sequence PCR (IRS-PCR). 188 Second, linear amplification via transposon insertion (LIANTI) and multiple displacement amplification (MDA).…”

“…153 Until recently, fluorescence in situ hybridization (FISH), digital PCR, BEAMing PCR, and RT-qPCR were the standard procedures for molecular analysis of specific genes in CTCs. 99,184,185 More sensitive methods, such as whole genome sequencing (WGS) and whole exome sequencing (WES), are currently being explored as more precise tools for the genomic characterization of individual cells (Figure 3 and Table 2).…”

Cancer Stem Cells (CSCs), Circulating Tumor Cells (CTCs) and Their Interplay with Cancer Associated Fibroblasts (CAFs): A New World of Targets and Treatments

“…They mainly circulate in the peripheral blood, lymphatic vessels, and into the stroma of the starting or metastatic lesions, representing the liquid stage of a solid tumor (Figure 1). Indeed, CTCs are vital components of liquid biopsies and have been under investigation for the identification of residual cancer, monitoring of therapy response, and prognosis of recurrence and survival [39][40][41]. Constituted by a pool of rare and highly heterogeneous cells, able to change their antigen expression, even during their travel through the body (e.g., thanks to Epithelial Mesenchymal transition, EMT) [42], they can mirror the disease characteristics and its evolution.…”

Frontiers in mass spectrometry–based clinical proteomics for cancer diagnosis and treatment

“… 1 As a result of the development of highly sensitive and specific genetic analysis technologies, several tests, including FoundationOne Liquid CDx and Guardant 360 CDx, have already been approved by the US Food and Drug Administration (FDA) as liquid biopsy tests for companion diagnostics. 2 However, the recent significant progress in various omics analytical technologies as well as data science has been remarkable. Although there have been clinical applications of genetic diagnosis, the integration of data from multiple modalities to transcend single‐omics is expected to improve in the future.…”