Circulating Tumor Cells Detection Methods Research Articles

The Role of Circulating Tumor Cells as a Liquid Biopsy for Cancer: Advances, Biology, Technical Challenges, and Clinical Relevance.

Cancer remains a leading cause of mortality worldwide, with metastasis significantly contributing to its lethality. The metastatic spread of tumor cells, primarily through the bloodstream, underscores the importance of circulating tumor cells (CTCs) in oncological research. As a critical component of liquid biopsies, CTCs offer a non-invasive and dynamic window into tumor biology, providing invaluable insights into cancer dissemination, disease progression, and response to treatment. This review article delves into the recent advancements in CTC research, highlighting their emerging role as a biomarker in various cancer types. We explore the latest technologies and methods for CTC isolation and detection, alongside novel approaches to characterizing their biology through genomics, transcriptomics, proteomics, and epigenetic profiling. Additionally, we examine the clinical implementation of these findings, assessing how CTCs are transforming the landscape of cancer diagnosis, prognosis, and management. By offering a comprehensive overview of current developments and potential future directions, this review underscores the significance of CTCs in enhancing our understanding of cancer and in shaping personalized therapeutic strategies, particularly for patients with metastatic disease.

Abstract 7487: Construction of a reliable CTC detection method and validity evaluation of CTC markers in colorectal cancer

Abstract Even in modern times when medical technology has advanced, cancer remains a life-threatening disease, and recurrence and metastasis are major issues in cancer treatment. The characteristics of cancer cells change with progression and treatment. Therefore, timely evaluation on their characteristics and decision on the treatment strategy are required. Circulating tumor cells (CTCs) are released into blood vessels in solid tumors and promote metastasis by circulating in the blood. CTCs are thus attractive targets for liquid biopsy and can provide useful information for selection of appropriate treatment. To obtain reliable results from CTC testing, it is important to prove that the detected cells are derived from cancerous tissue. In molecular tests targeting CTCs, it is still unclear whether the detected cells are derived from cancer tissue displaying genetic mutations. Aiming to establish reliable CTC testing, we have developed a simple method using molecular imaging flow cytometry to detect APC gene mutation together with Cytokeratin and Vimentin, which are epithelial-mesenchymal transition markers. Since, abnormalities in the APC gene are detected in 60-70% of colorectal cancer patients, detecting such mutations provides strong evidence that the detected cells are derived from cancerous tissue. Here, we show that upon evaluation of analytical performance of our method using cells isolated from cancerous tissue, our method showed high concordance rate against APC gene mutation. A clinical proof-of-concept using 5 mL of whole blood from colorectal cancer patients revealed that counts of cells with APC mutation in blood and cells with Cytokeratin and/or Vimentin expression in blood are highly correlated. Our results demonstrated a pathological stage-dependent increase in the count and frequency of Cytokeratin and/or Vimentin positive CTCs. We believe that our study not only establishes a practical approach for identifying CTCs in cancer patients but also provides potential implications in clinical practice, prognostic evaluation, and selection of treatment strategies. Citation Format: Yusuke Takahashi, Yuichi Ijiri, Shiki Fujino, Nakhaei Elnaz, Ayuko Kishimoto, Kentaro Shirai, Shigeki Iwanaga, Masatoshi Yanagida, Ali Asgar Bhagat, Norikatsu Miyoshi. Construction of a reliable CTC detection method and validity evaluation of CTC markers in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7487.

Isolation of Viable Epithelial and Mesenchymal Circulating Tumor Cells from Breast Cancer Patients.

Circulating tumor cells (CTCs) undergoing epithelial-mesenchymal transition (EMT) may exhibit more aggressive features than epithelial CTCs and are more frequently observed during disease progression. Therefore, detection and characterization of both epithelial and mesenchymal CTCs in cancer patients are urgently needed to allow for a better understanding of the metastatic process and more effective treatment. Here we describe a method for detection and isolation of viable epithelial and mesenchymal CTCs from peripheral blood of breast cancer patients. The method is based on density gradient centrifugation, multiplex immunofluorescent staining, and negative anti-CD45 selection. Cells obtained after the procedure are suitable for genomic or transcriptomic profiling, and they can also be isolated by micromanipulation for single-cell analysis.

Clinical application of circulating tumor cells

Abstract This narrative review aims to provide a comprehensive overview of the current state of circulating tumor cell (CTC) analysis and its clinical significance in patients with epithelial cancers. The review explores the advancements in CTC detection methods, their clinical applications, and the challenges that lie ahead. By examining the important research findings in this field, this review offers the reader a solid foundation to understand the evolving landscape of CTC analysis and its potential implications for clinical practice. The comprehensive analysis of CTCs provides valuable insights into tumor biology, treatment response, minimal residual disease detection, and prognostic evaluation. Furthermore, the review highlights the potential of CTCs as a non-invasive biomarker for personalized medicine and the monitoring of treatment efficacy. Despite the progress made in CTC research, several challenges such as standardization, validation, and integration into routine clinical practice remain. The review concludes by discussing future directions and the potential impact of CTC analysis on improving patient outcomes and guiding therapeutic decision-making in epithelial cancers.

Novel conditionally replicating adenovirus-mediated efficient detection of circulating tumor cells in lung cancer patients.

Circulating tumor cells (CTCs) are present in the blood of cancer patients from the early stage of cancer development, and their presence has been correlated with patient prognosis and treatment responses. Accordingly, CTCs have been attracting attention as a novel biomarker for early detection of cancer and monitoring of treatment responses. However, since patients typically have only a few CTCs per milliliter of blood, development of an accurate and highly sensitive CTC detection method is crucial. We previously developed a CTC detection method using a novel conditionally replicating adenovirus (Ad) that expresses green fluorescence protein (GFP) in a tumor cell-specific manner by expressing the E1 gene using a tumor-specific human telomerase reverse transcriptase (hTERT) promoter (rAdF35-142T-GFP). CTCs were efficiently detected using rAdF35-142T-GFP, but GFP expression levels in the CTCs and production efficiencies of rAdF35-142T-GFP were relatively low. In this study, in order to overcome these problems, we developed four types of novel GFP-expressing conditionally replicating Ads and examined their ability to visualize CTCs in the blood samples of lung cancer patients. Among the four types of novel recombinant Ads, the novel conditionally replicating Ad containing the 2A peptide and the GFP gene downstream of the E1A gene and the adenovirus death protein (ADP) gene in the E3 region (rAdF35-E1-2A-GFP-ADP) mediated the highest number of GFP-positive cells in the human cultured tumor cell lines. Titers of rAdF35-E1-2A-GFP-ADP were significantly higher (about 4-fold) than those of rAdF35-142T-GFP. rAdF35-E1-2A-GFP-ADP and rAdF35-142T-GFP efficiently detected CTCs in the blood of lung cancer patients at similar levels. GFP+/CD45- cells (CTCs) were found in 10 of 17 patients (58.8%) for both types of recombinant Ads.

Recent Update Roles of Magnetic Nanoparticles in Circulating Tumor Cell (CTC)/Non-CTC Separation.

Metastasis of cancer is a major cause of death worldwide. Circulating tumor cells (CTCs) are important in the metastatic process of cancer. CTCs are able to circulate in the bloodstream. Therefore, they can be used as biomarkers of metastasis. However, CTCs are rare when compared to a large number of blood cells in the blood. Many CTC detection methods have been developed to increase CTC detection efficiency. Magnetic nanoparticles (MNPs) have attracted immense attention owing to their potential medical applications. They are particularly appealing as a tool for cell separation. Because of their unique properties, MNPs are of considerable interest for the enrichment of CTCs through CTC or non-CTC separation. Herein, we review recent developments in the application of MNPs to separate CTCs or non-CTCs in samples containing CTCs. This review provides information on new approaches that can be used to detect CTCs in blood samples. The combination of MNPs with other particles for magnetic-based cell separation for CTC detection is discussed. Furthermore, different approaches for synthesizing MNPs are included in this review.

Hybrid chain reaction and selective recognition-based homogeneous dual-fluorescence analysis of circulating tumor cells in clinical ovarian cancer samples

BackgroundOncological analysis is important in tumor diagnosis. We constructed a dual-fluorescence and binary visual analysis system for circulating tumor cells (CTCs) using the folate receptor as a biomarker, combined with hybridization chain reaction and nanomaterial amplification. This strategy integrates terminal protection, selective recognition properties of N-methyl mesoporphyrin IX and CdTe quantum dots for Cu2+ and double-stranded templated copper nanoparticles, and inkjet printing technology. ResultsIn fluorescence mode, folate receptor and A2780 ovarian cancer cells were specifically detected with a limit of detection of 0.1 fg mL−1, and 10 cells mL−1 were observed. The detection limits of both the color and distance reading modes were comparable to those obtained in fluorescence mode. The applicability of the method for quantifying CTCs was validated using 27 (6 negative and 21 positive) clinical ovarian cancer samples; the results agreed with those of both the clinical folate receptor-polymerase chain reaction kit and radiological and pathological results. SignificanceThis dual-fluorescence and binary visual CTCs detection method provides multiple options for clinical tumor liquid biopsy.

Clinical implications and perspectives of portal venous circulating tumor cells in pancreatic cancer

Despite recent improvements in the diagnosis and treatment of pancreatic cancer (PC), clinical outcomes remain dismal. Moreover, there are no effective prognostic or predictive biomarkers or options beyond carbohydrate antigen 19-9 for personalized and precise treatment. Circulating tumor cells (CTCs), as a member of the liquid biopsy family, could be a promising biomarker; however, the rarity of CTCs in peripheral venous blood limits their clinical use. Because the first venous drainage of PC is portal circulation, the portal vein can be a more suitable location for the detection of CTCs. Endoscopic ultrasound-guided portal venous sampling of CTCs is both feasible and safe. Several studies have suggested that the detection rate and number of CTCs may be higher in the portal blood than in the peripheral blood. CTC counts in the portal blood are highly associated with hepatic metastasis, recurrence after surgery, and survival. The phenotypic and genotypic properties measured in the captured portal CTCs can help us to understand tumor heterogeneity and predict the prognosis of PC. Small sample sizes and heterogeneous CTC detection methods limit the studies to date. Therefore, a large number of prospective studies are needed to corroborate portal CTCs as a valid biomarker in PC.

Abstract 5602: Markers of hypoxic cells: Testing a pre-clinical detection assay

Abstract The proposed project aims to test the applicability of a novel set of patented organic compounds as markers of hypoxic circulating tumor cells (H-CTC) with potential pre-clinical relevance. Circulating tumor cells (CTC) are individual cells or clusters that can move from tumors to circulation invading other tissues. Often cells in the tumor need to adapt to low oxygen levels, generating a population of cells known as hypoxic cells that can survive low oxygen levels. These hypoxic cells can produce more cell junction proteins, augmenting connections between cells causing them to break away in clusters rather than individually. Clustered CTCs are much more efficient at metastasis formation. Release of CTC can also be stimulated by cancer treatments such as radiation and chemotherapy. To date, our research has generated in-vitro studies with a set of 3-nitrobenzazolo[3,2- a]quinolinium chloride salts (NBQS) demonstrating its capacity as markers of hypoxic human cancer cells in vitro. Comparison with the control Pimonidazole demonstrated the advantages of novel NBQ-TOM compounds as hypoxic marker. We here, aim to test the applicability of NBQS to identify hypoxic cells among circulating tumor cells (H-CTC). To date limited commercially CTC detection methods are available. Our application can be described as pre-clinical detection technology of hypoxic cancer cells serving also in cancer management. To determine the capacity of novel compound, NBQ-345 TOM as hypoxic fluorescent marker, colon tumor cells (COLO 205) are culture under hypoxic and aerobic environment and treated with NBQ-345TOM (25uM) for 24 hours. After treatment fluorescence is measured with an OPTIMA BMG Fluorimeter. Fluorescence emission results demonstrated significant formation of the NBQ-234 TOM fluorescent metabolite on hypoxic tumor cells in contrast to cells treated under aerobic environment. Also, fluorescence microscopy analysis of colon cancer cells treated for 24 hours with NBQ-345 TOM at hypoxic and aerobic conditions confirmed the stronger fluorescence generation at hypoxic conditions in contrast to cells at aerobic conditions. Citation Format: Beatriz Zayas, Karoline Rios, Luis Ortiz, Osvaldo Cox. Markers of hypoxic cells: Testing a pre-clinical detection assay. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5602.

Accurate isolation and detection of circulating tumor cells using enrichment-free multiparametric high resolution imaging.

The reliable and accurate detection of rare circulating tumor cells (CTCs) from cancer patient blood samples promises advantages in both research and clinical applications. Numerous CTC detection methods have been explored that rely on either the physical properties of CTCs such as density, size, charge, and/or their antigen expression profiles. Multiple factors can influence CTC recovery including blood processing method and time to processing. This study aimed to examine the accuracy and sensitivity of an enrichment-free method of isolating leukocytes (AccuCyte® system) followed by immunofluorescence staining and high-resolution imaging (CyteFinder® instrument) to detect CTCs. Healthy human blood samples, spiked with cancer cells from cancer cell lines, as well as blood samples obtained from 4 subjects diagnosed with cancer (2 pancreatic, 1 thyroid, and 1 small cell lung) were processed using the AccuCyte-CyteFinder system to assess recovery rate, accuracy, and reliability over a range of processing times. The AccuCyte-CyteFinder system was highly accurate (95.0%) at identifying cancer cells in spiked-in samples (in 7.5 mL of blood), even at low spiked-in numbers of 5 cells with high sensitivity (90%). The AccuCyte-CyteFinder recovery rate (90.9%) was significantly higher compared to recovery rates obtained by density gradient centrifugation (20.0%) and red blood cell lysis (52.0%). Reliable and comparable recovery was observed in spiked-in samples and in clinical blood samples processed up to 72 hours post-collection. Reviewer analysis of images from spiked-in and clinical samples resulted in high concordance (R-squared value of 0.998 and 0.984 respectively). The AccuCyte-CyteFinder system is as an accurate, sensitive, and clinically practical method to detect and enumerate cancer cells. This system addresses some of the practical logistical challenges in incorporating CTCs as part of routine clinical care. This could facilitate the clinical use of CTCs in guiding precision, personalized medicine.

A clinically feasible circulating tumor cell sorting system for monitoring the progression of advanced hepatocellular carcinoma

BackgroundHematogenous metastasis is essential for the progression of advanced hepatocellular carcinoma (HCC) and can occur even after patients receive multidisciplinary therapies, including immunotherapy and hepatectomy; circulating tumor cells (CTCs) are one of the dominant components of the metastatic cascade. However, the CTC capture efficiency for HCC is low due to the low sensitivity of the detection method. In this study, epithelial cell adhesion molecule (EpCAM)/vimentin/Glypican-3 (GPC3) antibody-modified lipid magnetic spheres (LMS) were used to capture tumor cells with epithelial phenotype, mesenchymal phenotype and GPC3 phenotype, respectively, in order to capture more CTCs with a more comprehensive phenotype for monitoring tumor metastasis.ResultsThe novel CTC detection system of Ep-LMS/Vi-LMS/GPC3-LMS was characterized by low toxicity, strong specificity (96.94%), high sensitivity (98.12%) and high capture efficiency (98.64%) in vitro. A sudden increase in CTC counts accompanied by the occurrence of lung metastasis was found in vivo, which was further validated by a clinical study. During follow-up, the rapid increase in CTCs predicted tumor progression in HCC patients. Additionally, genetic testing results showed common genetic alterations in primary tumors, CTCs and metastatic tissues. The proportion of patients predicted to benefit from immunotherapy with the CTC detection method was higher than that for the tissue detection method (76.47% vs. 41.18%, P = 0.037), guiding the application of clinical individualized therapy.ConclusionsThe Ep-LMS/Vi-LMS/GPC3-LMS sequential CTC capture system is convenient and feasible for the clinical prediction of HCC progression. CTCs captured by this system could be used as a suitable alternative to HCC tissue detection in guiding immunotherapy, supporting the clinical application of CTC liquid biopsy.

Sensitive detection of folate receptor-positive circulating tumor cells based on intracellular uptake of the PbS nanoparticle cluster-loaded phospholipid micelles decorated with folic acid in combination with E-DNA sensor

Developing methods for the circulating tumor cells (CTCs) detection is important for noninvasive cancer diagnosis. A sensitive method for homogeneous electrochemical detection of CTCs was developed based on the affinity of folic acid (FA) for folate receptor (FR), which is overexpressed on the CTC surface. The PbS nanoparticle cluster-loaded phospholipid micelles decorated with FA were prepared and used as a nanoprobe. The specific binding of FA to FR-positive CTCs leads to the uptake of the nanoprobes into the CTCs. Cellular imaging assay showed the excellent biocompatibility and selectivity of nanoprobes. After separation of intracellular nanoprobes and the residual free nanoprobes in the solution by centrifugation, nanoprobes in the cell were dissolved using acid. The amount of the target cells was quantified by the electrochemical detection of Pd2+ using the electrochemical DNA (E-DNA) sensor, which was fabricated based on the self-assembly of probe DNA on the flowerlike gold nanostructures modified the screen-printed carbon electrode (SPCE). Because of the large quantities of detectable Pd2+ contained in the nanoprobes, the signal amplification effect was achieved. The developed electrochemical assay allows the detection of ∼5 cells from 1 mL of sample. Studies with both healthy individuals and cancer patient blood samples demonstrate that the assay is sensitive and FR-positive CTCs specific.

Detection of Circulating Tumor Cells Using the Attune NxT.

Circulating tumor cells (CTCs) have been detected in many patients with different solid malignancies. It has been reported that presence of CTCs correlates with worse survival in patients with multiple types of cancer. Several techniques have been developed to detect CTCs in liquid biopsies. Currently, the only method for CTC detection that is approved by the Food and Drug Administration is CellSearch. Due to low abundance of CTCs in certain cancer types and in early stages of disease, its clinical application is currently limited to metastatic colorectal cancer, breast cancer and prostate cancer. Therefore, we aimed to develop a new method for the detection of CTCs using the Attune NxT-a flow cytometry-based application that was specifically developed to detect rare events in biological samples without the need for enrichment. When healthy donor blood samples were spiked with variable amounts of different EpCAM+EGFR+ tumor cell lines, recovery yield was on average 75%. The detection range was between 1000 and 10 cells per sample. Cell morphology was confirmed with the Attune CytPix. Analysis of blood samples from metastatic colorectal cancer patients, as well as lung cancer patients, demonstrated that increased EpCAM+EGFR+ events were detected in more than half of the patient samples. However, most of these cells showed no (tumor) cell-like morphology. Notably, CellSearch analysis of blood samples from a subset of colorectal cancer patients did not detect CTCs either, suggesting that these blood samples were negative for CTCs. Therefore, we anticipate that the Attune NxT is not superior to CellSearch in detection of low amounts of CTCs, although handling and analysis of samples is easier. Moreover, morphological confirmation is essential to distinguish between CTCs and false positive events.

Marker-free characterization of full-length transcriptomes of single live circulating tumor cells.

The identification and characterization of circulating tumor cells (CTCs) are important for gaining insights into the biology of metastatic cancers, monitoring disease progression, and medical management of the disease. The limiting factor in the enrichment of purified CTC populations is their sparse availability, heterogeneity, and altered phenotypes relative to the primary tumor. Intensive research both at the technical and molecular fronts led to the development of assays that ease CTC detection and identification from peripheral blood. Most CTC detection methods based on single-cell RNA sequencing (scRNA-seq) use a mix of size selection, marker-based white blood cell (WBC) depletion, and antibodies targeting tumor-associated antigens. However, the majority of these methods either miss out on atypical CTCs or suffer from WBC contamination. We present unCTC, an R package for unbiased identification and characterization of CTCs from single-cell transcriptomic data. unCTC features many standard and novel computational and statistical modules for various analyses. These include a novel method of scRNA-seq clustering, named deep dictionary learning using k-means clustering cost (DDLK), expression-based copy number variation (CNV) inference, and combinatorial, marker-based verification of the malignant phenotypes. DDLK enables robust segregation of CTCs and WBCs in the pathway space, as opposed to the gene expression space. We validated the utility of unCTC on scRNA-seq profiles of breast CTCs from six patients, captured and profiled using an integrated ClearCell FX and Polaris workflow that works by the principles of size-based separation of CTCs and marker-based WBC depletion.

Bioinspired nano-plate-coral platform enabled efficient detection of circulating tumor cells via the synergistic capture of multivalent aptamer and tumor cell membrane

Circulating tumor cells (CTCs) offer rich information for early disease diagnosis and therapy evaluation. However, the limited sensitivity, binding affinity, and stability of current monovalent recognition-based CTCs detection techniques remain a challenge for extending their applications. Inspired by the highly efficient predation manner of plate corals, we firstly introduce an efficient and sensitive biomimetic CTCs recognition platform based on the conjugation of multivalent aptamer onto tumor cell membrane-coated magnetic graphene oxide to form a plate coral-like CTCs capture nanoprobe (MNPA-TCMMGO). In this method, the tumor cell membrane was employed to provide a biomimetic homologous fluidic interface for targeting homologous tumor cells. At the same time, multivalent aptamers were used as capture probes, which greatly enhanced the binding affinity and association probability between aptamer and target cells via cooperative multivalent effect. The unique features (robustness, high binding affinity and specificity, and biocompatibility) of MNPA-TCMMGO allow efficient, sensitive, and specific capture of rare tumor cells from biological samples. More importantly, the captured cells could maintain good viability, which is crucial for downstream analysis. Therefore, our developed biomimetic approach offers a new way to address the limitations of current CTCs detection methods and presents considerable potential for clinical cancer diagnostics.

Circulating tumor cells in neuroblastoma: Current status and future perspectives.

Neuroblastoma is the most common extracranial solid tumor in children, accounting for 10% to 20% of deaths of pediatric malignancies. Due to the poor prognosis and significant biological heterogeneity of neuroblastoma, it is essential to develop personalized therapeutics and monitor treatment response. Circulating tumor cells (CTCs), as one of the important analytes for liquid biopsy, could facilitate response assessment and outcome prediction for patients in a non-invasive way. Several methods and platforms have been used for the enrichment and detection of CTCs. The enumeration of CTCs counts and evaluation of tumor-specific mRNA transcript levels could provide prognostic information at diagnosis, during or after chemotherapy, and during the process of disease progression. So far, studies into neuroblastoma CTCs are only in the preliminary stages. The quality-controlled large prospective cohort studies are needed to evaluate the clinical significance and statistical rigor of CTC detection methods. Moreover, there remains a lot to be explored and investigated in genotyping characterization of neuroblastoma (NB) CTCs and construction of in-vitro or in-vivo functional models. CTCs and circulating tumor DNA (ctDNA) analysis will be complementary in understanding tumor heterogeneity and evolution over the course of therapy for patients with NB in the future.

The Discovery of Novel Circulating Cancer-Related Cells in Circulation Poses New Challenges to Microfluidic Devices for Enrichment and Detection.

Circulating tumor cells (CTCs) enumeration has been widely used as a surrogate predictive marker for early diagnoses, the evaluation of chemotherapy efficacy, and cancer prognosis. Microfluidic technologies for CTCs enrichment and detection have been developed and commercialized as automation platforms. Currently, in addition to CTCs, some new types of circulating cancer-related cells (e.g., CCSCs, CTECs, CAMLs, and heterotypic CTC clusters) in circulation are also reported to be correlated to cancer diagnosis, metastasis, or prognosis. And they widely differ from the conventional CTCs in positive markers, cellular morphology, or size, which presents a new technological challenge to microfluidic devices that use affinity-based capture methods or size-based filtration methods for CTCs detection. This review focuses on the biological and physical properties as well as clinical significance of the novel circulating cancer-related cells, and discusses the challenges of their discovery to microfluidic chip for enrichment. Finally, the current challenges of CTCs detection in clinical application and future opportunities are also discussed.

Application of Microfluidics in Detection of Circulating Tumor Cells.

Tumor metastasis is one of the main causes of cancer incidence and death worldwide. In the process of tumor metastasis, the isolation and analysis of circulating tumor cells (CTCs) plays a crucial role in the early diagnosis and prognosis of cancer patients. Due to the rarity and inherent heterogeneity of CTCs, there is an urgent need for reliable CTCs separation and detection methods in order to obtain valuable information on tumor metastasis and progression from CTCs. Microfluidic technology is increasingly used in various studies of CTCs separation, identification and characterization because of its unique advantages, such as low cost, simple operation, less reagent consumption, miniaturization of the system, rapid detection and accurate control. This paper reviews the research progress of microfluidic technology in CTCs separation and detection in recent years, as well as the potential clinical application of CTCs, looks forward to the application prospect of microfluidic technology in the treatment of tumor metastasis, and briefly discusses the development prospect of microfluidic biosensor.

Exploring the Clinical Utility of Pancreatic Cancer Circulating Tumor Cells.

Pancreatic ductal adenocarcinoma (PDAC) is the most frequent pancreatic cancer type, characterized by a dismal prognosis due to late diagnosis, frequent metastases, and limited therapeutic response to standard chemotherapy. Circulating tumor cells (CTCs) are a rare subset of tumor cells found in the blood of cancer patients. CTCs has the potential utility for screening, early and definitive diagnosis, prognostic and predictive assessment, and offers the potential for personalized management. However, a gold-standard CTC detection and enrichment method remains elusive, hindering comprehensive comparisons between studies. In this review, we summarize data regarding the utility of CTCs at different stages of PDAC from early to metastatic disease and discuss the molecular profiling and culture of CTCs. The characterization of CTCs brings us closer to defining the specific CTC subpopulation responsible for metastasis with the potential to uncover new therapies and more effective management options for PDAC.

Graphene-Based Biosensors with High Sensitivity for Detection of Ovarian Cancer Cells

Ovarian cancer has the highest mortality rate in the world. Therefore, it is urgent but still challenging to develop an efficient circulating tumor cell (CTC) detection method to sensitively detect ovarian cancer. To address such issues, herein, for the first time, we present a novel CTC detection method for ovarian cancer cells by designing sensitive and rapid graphene-based biosensors. This graphene-based sensor, consisting of a cell pool and two electrodes, can be prepared by a conventional chip fabrication process. It demonstrates high-sensitivity detection even for several ovarian cancer cells by comparing the electrical signal before and after adding cell solution. Moreover, the graphene-based biosensors can perform rapid detection with good repeatability. This suggests that this novel method is possible to use for the early detection of ovarian cancer with very low CTC cell concentration. This work provides a novel and quick strategy to detect ovarian cancer and further judge or predict the risk of the transfer of ovarian cancer.