Circulating Tumor Nucleic Acids Research Articles

MicroRNA in lung cancer-a novel potential way for early diagnosis and therapy.

Lung cancer is the most common cause of cancer-related deaths in the world. One of the reasons of poor prognosis and high mortality of lung cancer patients is the diagnosis of the disease in its advanced stage. Despite innovative diagnostic methods and multiple completed and ongoing clinical trials aiming at therapy improvement, no significant increase in patients' long-term survival has been noted over last decades. Patients would certainly benefit from early detection of lung cancer. Therefore, it is crucial to find new biomarkers that can help predict outcomes and tumor responses in order to maximize therapy effectiveness and avoid over- or under-treating patients with lung cancer. Nowadays, scientists' attention is mainly dedicated to so-called liquid biopsy, which is fully non-invasive and easily available method based on simple blood draw. Among common liquid biopsy elements, circulating tumor nucleic acids are worth mentioning. Epigenetic biomarkers, particularly miRNA expression, have several distinct features that make them promising prognostic markers. In this review, we described miRNA's involvement in tumorigenesis and present it as a predictor of cancer development and progression, potential indicator of treatment efficacy, and most importantly promising therapeutic target.

Multifunctional Hybrid Nanozymes for Magnetic Enrichment and Bioelectrocatalytic Sensing of Circulating Tumor RNA during Minimal Residual Disease Monitoring

Iron oxide nanozymes are a form of nanomaterial with both superparamagnetic and enzyme-mimicking properties. Ongoing research efforts have been made to create multifunctional iron oxide hybrid nanozymes with auxiliary properties through biomolecular modifications. Such iron oxide hybrid nanozymes can be useful for rapid and cost-effective analysis of circulating tumor nucleic acids (ctNAs) in patient liquid biopsies during minimal residual disease (MRD) monitoring of cancer recurrence. Herein, the use of streptavidin-modified iron oxide hybrid nanozymes is reported for magnetic enrichment and bioelectrocatalytic sensing of three prostate cancer (PCa) ctRNA biomarkers with high detection specificity and sensitivity (10 copies) over an ultrabroad dynamic range (five orders of magnitude). Furthermore, the feasibility of ctRNA analysis for pre- and post-cancer treatment MRD monitoring is demonstrated using PCa urinary liquid biopsy samples.

Gold island‐enhanced multiplex quantum dots fluorescent system for biomedical analysis of circulating tumor nucleic acids

AbstractCirculating tumor nucleic acids (CTNAs) have been employed as the potential markers for tumor diagnosis and management, which are highly correlated with the tumorigenesis, progression, and metastasis processes. Therefore, it is important to develop a highly‐sensitive and reliable method for the detection of CTNAs, especially the multiplex point mutation detection of blood‐derived CTNAs. Herein, a versatile gold island‐enhanced multiplex quantum dots (GIEM‐QDs) fluorescent platform was constructed for the highly‐sensitive detection of CTNAs in serum. The GIEM fluorescent strategy was designed as the highly‐efficient signal giving‐out mode which could amplify the fluorescence intensity of QDs, thus realizing a homogeneous platform for the enrichment, multiplex detection, and point mutations monitoring of CTNAs with the principle of base‐stacking. A high sensitivity of 10 amol and desirable specificity was achieved, and the performance index for analysis of clinical tumor patients’ samples indicated that the GIEM‐QDs fluorescent strategy could realize multiplex point mutation detection of CTNAs in complex blood samples. Hence, this platform could achieve a high detection rate in clinical samples that suitably met the clinical requirements for multiplex detection and point mutations monitoring of CTNAs, and thus has the potential to serve as the tumor liquid biopsy strategy based on CTNAs.

Saliva Based Liquid Biopsies in Head and Neck Cancer: How Far Are We From the Clinic?

Head and neck cancer (HNC) remains to be a major cause of mortality worldwide because of confounding factors such as late-stage tumor diagnosis, loco-regional aggressiveness and distant metastasis. The current standardized diagnostic regime for HNC is tissue biopsy which fails to determine the thorough tumor dynamics. Therefore, due to the ease of collection, recent studies have focused on the utility of saliva based liquid biopsy approach for serial sampling, early diagnosis, prognosis, longitudinal monitoring of disease progression and treatment response in HNC patients. Saliva collection is convenient, non-invasive, and pain-free and offers repetitive sampling along with real time monitoring of the disease. Moreover, the detection, isolation and analysis of tumor-derived components such as Circulating Tumor Nucleic Acids (CTNAs), Extracellular Vesicles (EVs), Circulating Tumor Cells (CTCs) and metabolites from saliva can be used for genomic and proteomic examination of HNC patients. Although, these circulatory biomarkers have a wide range of applications in clinical settings, no validated data has yet been established for their usage in clinical practice for HNC. Improvements in isolation and detection technologies and next-generation sequencing analysis have resolved many technological hurdles, allowing a wide range of saliva based liquid biopsy application in clinical backgrounds. Thus, in this review, we discussed the rationality of saliva as plausible biofluid and clinical sample for diagnosis, prognosis and therapeutics of HNC. We have described the molecular components of saliva that could mirror the disease status, recent outcomes of salivaomics associated with HNC and current technologies which have the potential to improve the clinical value of saliva in HNC.

The Role of Small Extracellular Vesicles in the Progression of Colorectal Cancer and Its Clinical Applications.

Colorectal cancer (CRC) is one of the most common cancers worldwide and a longstanding critical challenge for public health. Screening has been suggested to effectively reduce both the incidence and mortality of CRC. However, the drawback of the current screening modalities, both stool-based tests and colonoscopies, is limited screening adherence, which reduces the effectiveness of CRC screening. Blood tests are more acceptable than stool tests or colonoscopy as a first-line screening approach. Therefore, identifying blood biomarkers for detecting CRC and its precancerous neoplasms is urgently needed to fulfill the unmet clinical need. Currently, many kinds of blood contents, such as circulating tumor cells, circulating tumor nucleic acids, and extracellular vesicles, have been investigated as biomarkers for CRC detection. Among these, small extracellular vesicles (sEVs) have been demonstrated to detect CRC effectively in recent reports. sEVs enable intercellular shuttling—for instance, trafficking between recipient cancer cells and stromal cells—which can affect tumor initiation, proliferation, angiogenesis, immune regulation; metastasis, the cancer-specific molecules, such as proteins, microRNAs, long noncoding RNAs, and circular RNAs, loaded into cancer-derived sEVs may serve as biomarkers for the detection of cancers, including CRC. Indeed, accumulating evidence has shown that nucleic acids and proteins contained in CRC-derived sEVs are effective as blood biomarkers for CRC detection. However, investigations of the performance of sEVs for diagnosing CRC in clinical trials remains limited. Thus, the effectiveness of sEV biomarkers for diagnosing CRC needs further validation in clinical trials.

Liquid Biopsy and Lymphoma Monitoring in Clinical Practice

INTRODUCTIONLymphomas represent the fourth most frequent type of cancer, 90% of them arising from B cell lymphocytes. Despite their high prevalence, around 40% remain incurable because of refractoriness to current chemoimmunotherapy or disease relapse after obtaining response (Li et al., 2018; Meng et al., 2020). The cell of origin is a B lymphocyte with a unique B cell receptor (BCR). The BCR is an immunoglobulin composed of two heavy chains (IgH) and two light chains (IgL) whose genes have multiple coding segments that through rearrangement first and further somatic hypermutation in the germinal center, generate a unique sequence that could be used to monitor the treatment response (Seifert et al., 2019; Wang et al., 2020). This project studies the use of next-generation sequencing (NGS) to characterize and monitor such IgH clonality. The use of liquid biopsy samples would provide a minimally invasive method to identify refractory or relapse-risk patients since all of them will have residual tumor cells after treatment.METHODSThe sample size of the study was 53 patients with several types of B-cell lymphomas. The IgH gene of the tumor clone was characterized from DNA of tumor samples at diagnosis by NGS and Sanger. The monitoring of this clone was studied by NGS from DNA and circulating tumor nucleic acids (ctNAs) during and after receiving treatment and at different times after clinical response was stablished (CR or PR). Relapse samples were analyzed by NGS and Sanger.RESULTSCharacterization of the tumor clone IgH rearrangement is achieved in 45 of the 53 patients with B-cell lymphoma included in the study. As shown in Figure 1, after the two different amplification PCRs results are similar. In contrast, after sequencing the results obtained by Sanger and NGS are very different. In NGS, thanks to the massive amplification prior to sequencing, it is identify the tumor clone in approximately 80% of the samples. It is shown that the effectiveness in characterization is dependent on the origin of the DNA sample, with fresh material samples being the optimal (Figure 1).In monitoring, samples of different origin are used as shown in Figure 2. About 50% of these samples are plasma ctNAs whose average efficiency in the detection of IgH gene rearrangement is 73.3%, with a clear positive correlation between the sensitivity and the toal volume of plasma processed more starting plasma used (2 mL efficiency of 84.09%).Monitoring makes it possible to classify patients into three different groups (Figure 3): patients with complete remission, patients refractory to the different lines of treatment and patients with apparent complete response and subsequent relapse. In patients with complete response, the tumor clone decreases during treatment and at the end of the line it is no longer detectable, nor in subsequent follow-up samples. With respect to refractory patients, it is observed that the tumor clone remains present despite subsequent lines of treatment. Finally, in patients achieving CR with subsequent relapse, the clone can be detected in a small percentage at the end of the treatment schedule and remains present until relapse.A section of patients under treatment is also shown (Figure 3) to demonstrate the application of the study to clinical practice. Two patients with apparent complete response, one of them in complete remission and the other with a high risk of relapse, requiring a more exhaustive follow-up.The monitoring results obtained by flow cytometry are shown being these, in general, concordant. In some cases NGS shows greater sensitivity.CONCLUSIONThe use of NGS and liquid biopsy samples provides a minimally invasive method to monitor the IgH gene rearrangement of the tumor clone of patients with B-cell lymphomas. In our experience, patients in remission can be clearly differentiated from those who are refractory or at risk of relapse. facilitating their treatment strategy and clinical decision making. [Display omitted] DisclosuresFerrer Lores: Janssen: Membership on an entity's Board of Directors or advisory committees. Terol: BMS: Consultancy; Hospital Clinico Valencia: Current Employment; Roche: Consultancy; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: Travel, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Travel; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel.

Protein biomarkers in breast cancer-derived extracellular vesicles for use in liquid biopsies.

Breast cancer is the most common malignant disease in women worldwide. Early diagnosis and treatment can greatly improve the management of breast cancer. Liquid biopsies are becoming convenient detection methods for diagnosing and monitoring breast cancer due to their noninvasiveness and ability to provide real-time feedback. A range of liquid biopsy markers, including circulating tumor proteins, circulating tumor cells, and circulating tumor nucleic acids, have been implemented for breast cancer diagnosis and prognosis, with each having its own advantages and limitations. Circulating extracellular vesicles are messengers of intercellular communication that are packed with information from mother cells and are found in a wide variety of bodily fluids; thus, they are emerging as ideal candidates for liquid biopsy biomarkers. In this review, we summarize extracellular vesicle protein markers that can be potentially used for the early diagnosis and prognosis of breast cancer or determining its specific subtypes.

Liquid Biomarkers for Improved Diagnosis and Classification of CNS Tumors

Liquid biopsy, as a non-invasive technique for cancer diagnosis, has emerged as a major step forward in conquering tumors. Current practice in diagnosis of central nervous system (CNS) tumors involves invasive acquisition of tumor biopsy upon detection of tumor on neuroimaging. Liquid biopsy enables non-invasive, rapid, precise and, in particular, real-time cancer detection, prognosis and treatment monitoring, especially for CNS tumors. This approach can also uncover the heterogeneity of these tumors and will likely replace tissue biopsy in the future. Key components of liquid biopsy mainly include circulating tumor cells (CTC), circulating tumor nucleic acids (ctDNA, miRNA) and exosomes and samples can be obtained from the cerebrospinal fluid, plasma and serum of patients with CNS malignancies. This review covers current progress in application of liquid biopsies for diagnosis and monitoring of CNS malignancies.

Liquid biopsy in thyroid cancer: from circulating biomarkers to a new prospective of tumor monitoring and therapy.

Recently, liquid biopsy has attracted much interest as a tool for early cancer screening, prognosis, monitoring and response to treatment in many different cancer types. Indeed, liquid biopsies can be repeatedly performed in a noninvasive way, at lower cost and without the risks associated to the classic tissue biopsy. The objective of this monography was to describe the main components studied in liquid biopsy (circulating tumor nucleic acids, circulating tumor cells and extracellular vesicles) and how they have been explored in thyroid cancer, through an in-depth scientific literature review. While circulating tumor cells are the most represented component in the literature of liquid biopsy in thyroid cancer, circulating tumor nucleic acids and extracellular vesicles have also been recently explored. One important challenge in this field of research, especially for differentiated thyroid cancer, has been the low quantity of circulating components with respect to other cancer types, requiring more advanced techniques for both isolation and analysis. Despite these limitations, liquid biopsy showed promise as an additional noninvasive tool for diagnosis, prognosis, to predict outcome and therapeutic response in differentiated, medullary and anaplastic thyroid cancer.

Liquid biopsy in thyroid cancer: from circulating biomarkers to a new prospective of tumor monitoring and therapy.

Recently, liquid biopsy has attracted much interest as a tool for early cancer screening, prognosis, monitoring and response to treatment in many different cancer types. Indeed, liquid biopsies can be repeatedly performed in a non-invasive way, at lower cost and without the risks associated to the classic tissue biopsy. The objective of this monography is to describe the main components studied in liquid biopsy (circulating tumor nucleic acids, circulating tumor cells and extracellular vesicles) and how they have been explored in thyroid cancer, through an in-depth scientific literature review. While circulating tumor cells are the most represented component in the literature of liquid biopsy in thyroid cancer, circulating tumor nucleic acids and extracellular vesicles have also been recently explored. One important challenge in this field of research, especially for differentiated thyroid cancer, has been the low quantity of circulating components with respect to other cancer types, requiring more advanced techniques for both isolation and analysis. Despite these limitations, liquid biopsy showed promise as an additional non-invasive tool for diagnosis, prognosis, to predict outcome and therapeutic response in differentiated, medullary and anaplastic thyroid cancer.

Detection of BRAF splicing variants in plasma-derived cell-free nucleic acids and extracellular vesicles of melanoma patients failing targeted therapy therapies.

The analysis of plasma circulating tumour nucleic acids provides a non-invasive approach to assess disease burden and the genetic evolution of tumours in response to therapy. BRAF splicing variants are known to confer melanoma resistance to BRAF inhibitors. We developed a test to screen cell-free RNA (cfRNA) for the presence of BRAF splicing variants. Custom droplet digital PCR assays were designed for the detection of BRAF splicing variants p61, p55, p48 and p41 and then validated using RNA from cell lines carrying these variants. Evaluation of plasma from patients with reported objective response to BRAF/MEK inhibition followed by disease progression was revealed by increased circulating tumour DNA (ctDNA) in 24 of 38 cases at the time of relapse. Circulating BRAF splicing variants were detected in cfRNA from 3 of these 38 patients; two patients carried the BRAF p61 variant and one the p55 variant. In all three cases the presence of the splicing variant was apparent only at the time of progressive disease. BRAF p61 was also detectable in plasma of one of four patients with confirmed BRAF splicing variants in their progressing tumours. Isolation and analysis of RNA from extracellular vesicles (EV) from resistant cell lines and patient plasma demonstrated that BRAF splicing variants are associated with EVs. These findings indicate that in addition to plasma ctDNA, RNA carried by EVs can provide important tumour specific information.

Magnetic nanomaterial–based electrochemical biosensors for the detection of diverse circulating cancer biomarkers

Electrochemical biosensors are highly compatible with modern advancements in magnetic nanomaterials. In particular, the versatile nature of magnetic nanomaterials as a universal platform for selective isolation of diverse forms of cancer biomarkers in body circulation, is highly synergistic with electrochemical biosensors for elevating biosensing performance to unprecedented levels. Such diverse circulating target biomolecules include cell surface proteins of circulating tumor cells and extracellular vesicles (EVs), as well as circulating tumor nucleic acids (i.e. ctDNA/ctRNA). This focussed review serves to discuss the latest work in the fields of magnetic nanomaterials and electrochemistry to tackle existing analysis challenges of diverse circulating biomarkers in cancer.

The Role of Liquid Biopsies in Detecting Molecular Tumor Biomarkers in Brain Cancer Patients.

Glioblastoma multiforme (GBM) is one of the most lethal primary central nervous system cancers with a median overall survival of only 12–15 months. The best documented treatment is surgical tumor debulking followed by chemoradiation and adjuvant chemotherapy with temozolomide, but treatment resistance and therefore tumor recurrence, is the usual outcome. Although advances in molecular subtyping suggests GBM can be classified into four subtypes, one concern about using the original histology for subsequent treatment decisions is that it only provides a static snapshot of heterogeneous tumors that may undergo longitudinal changes over time, especially under selective pressure of ongoing therapy. Liquid biopsies obtained from bodily fluids like blood and cerebro-spinal fluid (CSF) are less invasive, and more easily repeated than surgery. However, their deployment for patients with brain cancer is only emerging, and possibly suppressed clinically due to the ongoing belief that the blood brain barrier prevents the egress of circulating tumor cells, exosomes, and circulating tumor nucleic acids into the bloodstream. Although brain cancer liquid biopsy analyses appear indeed challenging, advances have been made and here we evaluate the current literature on the use of liquid biopsies for detection of clinically relevant biomarkers in GBM to aid diagnosis and prognostication.

Liquid Biopsies in Hepatocellular Carcinoma: Are We Winning?

Hepatocellular carcinoma (HCC) represents the sixth most common cancer worldwide and the third most common cause of cancer-related death. One of the major problems faced by researchers and clinicians in this area is the lack of reliable disease biomarkers, which would allow for an earlier diagnosis, follow-up or prediction of treatment response, among others. In this regard, the “HCC circulome”, defined as the pool of circulating molecules in the bloodstream derived from the primary tumor, represents an appealing target, the so called liquid biopsy. Such molecules encompass circulating tumor proteins, circulating tumor cells (CTCs), extracellular vesicles (EVs), tumor-educated platelets (TEPs), and circulating tumor nucleic acids, namely circulating tumor DNA (ctDNA) and circulating tumor RNA (ctRNA). In this article, we summarize recent findings highlighting the promising role of liquid biopsies as novel potential biomarkers in HCC, emphasizing on its clinical performance.

Liquid Biopsy as Novel Tool in Precision Medicine: Origins, Properties, Identification and Clinical Perspective of Cancer's Biomarkers.

In recent years, there has been an increase in knowledge of cancer, accompanied by a technological development that gives rise to medical oncology. An instrument that allows the implementation of individualized therapeutic strategies is the liquid biopsy. Currently, it is the most innovative methodology in medical oncology. Its high potential as a tool for screening and early detection, the possibility of assessing the patient’s condition after diagnosis and relapse, as well as the effectiveness of real-time treatments in different types of cancer. Liquid biopsy is capable of overcoming the limitations of tissue biopsies. The elements that compose the liquid biopsy are circulating tumor cells, circulating tumor nucleic acids, free of cells or contained in exosomes, microvesicle and platelets. Liquid biopsy studies are performed on various biofluids extracted in a non-invasive way, and they can be performed both from the blood and in urine, saliva or cerebrospinal fluid. The development of genotyping techniques, using the elements that make up liquid biopsy, make it possible to detect mutations, intertumoral and intratumoral heterogeneity, and provide molecular information on cancer for application in medical oncology in an individualized way in different types of tumors. Therefore, liquid biopsy has the potential to change the way medical oncology could predict the course of the disease.

Sensor-Integrated Microfluidic Approaches for Liquid Biopsies Applications in Early Detection of Cancer.

Cancer represents one of the conditions with the most causes of death worldwide. Common methods for its diagnosis are based on tissue biopsies—the extraction of tissue from the primary tumor, which is used for its histological analysis. However, this technique represents a risk for the patient, along with being expensive and time-consuming and so it cannot be frequently used to follow the progress of the disease. Liquid biopsy is a new cancer diagnostic alternative, which allows the analysis of the molecular information of the solid tumors via a body fluid draw. This fluid-based diagnostic method displays relevant advantages, including its minimal invasiveness, lower risk, use as often as required, it can be analyzed with the use of microfluidic-based platforms with low consumption of reagent, and it does not require specialized personnel and expensive equipment for the diagnosis. In recent years, the integration of sensors in microfluidics lab-on-a-chip devices was performed for liquid biopsies applications, granting significant advantages in the separation and detection of circulating tumor nucleic acids (ctNAs), circulating tumor cells (CTCs) and exosomes. The improvements in isolation and detection technologies offer increasingly sensitive and selective equipment’s, and the integration in microfluidic devices provides a better characterization and analysis of these biomarkers. These fully integrated systems will facilitate the generation of fully automatized platforms at low-cost for compact cancer diagnosis systems at an early stage and for the prediction and prognosis of cancer treatment through the biomarkers for personalized tumor analysis.

Molybdenum disulfide@5-carboxyfluorescein-probe biosensor for unamplified specific fragment detection in long nucleic acids based on magnetic composite probe-actuated deblocking of secondary structure.

Secondary structures in long circulating tumor nucleic acids have potential obstacles for specific location point hybridized detection of gene fragments. The exploration of biosensing strategies requires selectively changing the nucleic acids conformation and inducing signal switching. Herein, a self-assembled magnetic composite probe (MCP) was fabricated by the hybridization reaction of Linker DNA and a "Y"-junction-DNA nanostructure on the surface of magnetic beads, contributing to the capture, secondary structure unlocking, and enrichment of the PML/RARα DNA "L" subtype. Then, by integrating the MCP-actuated reactor, a one-step "off-on" signal switching MoS2@FAM-probe biosensing method was developed for the efficient detection of the PML/RARα DNA "L" subtype. The proposed biosensor was capable of detecting 100 bases PML/RARα DNA "L" subtype with a wide linear range of 1 pM to 200 nM and a limit of detection down to 0.223 pM without signal amplification. In addition, the biosensing method was successfully applied for the detection of target in serum samples. It is worth pointing out that this simple biosensing strategy could enable long nucleic acids fragments with secondary structures from ctDNA and ctRNA to be quantitatively assayed based on direct hybridization.

The new horizon of liquid biopsy in sarcoma: the potential utility of circulating tumor nucleic acids.

The diagnosis, treatment and prognosis of sarcoma are mainly dependent on tissue biopsy, which is limited in its ability to provide a panoramic view into the dynamics of tumor progression. In addition, effective biomarkers to monitor the progression and therapeutic response of sarcoma are lacking. Liquid biopsy, a recent technological breakthrough, has gained great attention in the last few decades. Nucleic acids (such as DNA, mRNAs, microRNAs, and long non-coding RNAs) that are released from tumors circulate in the blood of cancer patients and can be evaluated through liquid biopsy. Circulating tumor nucleic acids reflect the intertumoral and intratumoral heterogeneity, and thus liquid biopsy provides a noninvasive strategy to examine these molecules compared with traditional tissue biopsy. Over the past decade, a great deal of information on the potential utilization of circulating tumor nucleic acids in sarcoma screening, prognosis and therapy efficacy monitoring has emerged. Several specific gene mutations in sarcoma can be detected in peripheral blood samples from patients and can be found in circulating tumor DNA to monitor sarcoma. In addition, circulating tumor non-coding RNA may also be a promising biomarker in sarcoma. In this review, we discuss the clinical application of circulating tumor nucleic acids as blood-borne biomarkers in sarcoma.

Clinical feasibility of NGS liquid biopsy analysis in NSCLC patients.

BackgroundAnalysis of circulating tumor nucleic acids in plasma of Non-Small Cell Lung Cancer (NSCLC) patients is the most widespread and documented form of "liquid biopsy" and provides real-time information on the molecular profile of the tumor without an invasive tissue biopsy.MethodsLiquid biopsy analysis was requested by the referral physician in 121 NSCLC patients at diagnosis and was performed using a sensitive Next Generation Sequencing assay. Additionally, a comparative analysis of NSCLC patients at relapse following EGFR Tyrosine Kinase Inhibitor (TKIs) treatment was performed in 50 patients by both the cobas and NGS platforms.ResultsAt least one mutation was identified in almost 49% of the cases by the NGS approach in NSCLC patients analyzed at diagnosis. In 36 cases with paired tissue available a high concordance of 86.11% was observed for clinically relevant mutations, with a Positive Predictive Value (PPV) of 88.89%. Furthermore, a concordance rate of 82% between cobas and the NGS approach for the EGFR sensitizing mutations (in exons 18, 19, 21) was observed in patients with acquired resistance to EGFR TKIs, while this concordance was 94% for the p.T790M mutation, with NGS being able to detect this mutation in three 3 additional patients.ConclusionsThis study indicates the feasibility of circulating tumor nucleic acids (ctNA) analysis as a tumor biopsy surrogate in clinical practice for NSCLC personalized treatment decision making. The use of new sensitive NGS techniques can reliably detect tumor-derived mutations in liquid biopsy and provide clinically relevant information both before and after targeted treatment in patients with NSCLC. Thus, it could aid physicians in treatment decision making in clinical practice.

High-Performance Nucleic Acid Sensors for Liquid Biopsy Applications.

Circulating tumour nucleic acids (ctNAs) are released from tumours cells and can be detected in blood samples, providing a way to track tumors without requiring a tissue sample. This "liquid biopsy" approach has the potential to replace invasive, painful, and costly tissue biopsies in cancer diagnosis and management. However, a very sensitive and specific approach is required to detect relatively low amounts of mutant sequences linked to cancer because they are masked by the high levels of wild-type sequences. This review discusses high-performance nucleic acid biosensors for ctNA analysis in patient samples. We compare sequencing- and amplification-based methods to next-generation sensors for ctDNA and ctRNA (including microRNA) profiling, such as electrochemical methods, surface plasmon resonance, Raman spectroscopy, and microfluidics and dielectrophoresis-based assays. We present an overview of the analytical sensitivity and accuracy of these methods as well as the biological and technical challenges they present.