Circulating tumor DNA (ctDNA) as a pan-cancer screening test: is it finally on the horizon? (original) (raw)
Related papers
Circulating tumor DNA in cancer diagnosis, monitoring, and prognosis
2022
Background: Circulating tumor DNA (ctDNA) has become one of the crucial components for cancer detection with the increase of precision medicine practice. ctDNA has great potential as a blood-based biomarker for the detection and treatment of cancer in its early stages. The purpose of this article was to discuss ctDNA and how it can be utilized to detect cancer. The benefits and drawbacks of this cancer detection technology, as well as the field's future possibilities in various cancer management scenarios, are discussed. Main text: ctDNA has clinical applications in disease diagnosis and monitoring. It can be used to identify mutations of interest and genetic heterogeneity. Another use of ctDNA is to monitor the effects of therapy by detecting mutation-driven resistance. Different technologies are being used for the detection of ctDNA. Next-generation sequencing, digital PCR, real-time PCR, and mass spectrometry are used. Using dPCR makes it possible to partition and analyze individual target sequences from a complex mixture. Mass-spectrometry technology enables accurate detection and quantification of ctDNA mutations at low frequency. Surface-enhanced Raman spectroscopy (SERS) and UltraSEEK are two systems based on this technology. There is no unified standard for detecting ctDNA as it exists in a low concentration in blood. As there is no defined approach, false positives occur in several methods due to inadequate sensitivities. Techniques used in ctDNA are costly and there is a limitation in clinical settings. Short conclusion: A detailed investigation is urgently needed to increase the test's accuracy and sensitivity. To find a standard marker for all forms of cancer DNA, more study is needed. Low concentrations of ctDNA in a sample require improved technology to provide the precision that low concentrations of ctDNA in a sample afford.
Circulating tumor DNA in blood: Future genomic biomarkers for cancer detection
Experimental Hematology, 2018
Cancer is characterized by Darwinian evolution and a primary cause of mortality and morbidity around the globe. Over the preceding decade, the treatment of cancer has been markedly improved by many targeted therapies but these treatments have given birth to new challenges and issues. Clonal evolution and tumor heterogeneity accords a significant challenge in designing cancer therapies. Fortunately, these restrictions have been overcome by technological advancements allowing us to track both genetic and epigenetic aberrations. Cell-free circulating tumor DNA (ctDNA) analysis or "liquid biopsy" from blood sample can bestow us with the opportunity to track genetic landscape of all the cancerous lesions. This review focuses on ctDNA analysis as a non-invasive method and a versatile biomarker for cancer treatment and technological advancements for ctDNA analysis. This method may able to cope with all the challenges associated with previous cancer therapies and has the potential to monitor minimal residual disease, tumor burden, therapy response and provide rapid detection of relapse. However, still there are many challenges that need to be addressed. Future prognosis, diagnosis and analysis of circulating tumor DNA requires reproducibility and accuracy of results which is not possible without the validation and optimization of procedures. Integrated digital error suppression is so far show promise in detection of ctDNA in cancer.
Clinical Chemistry
Background Protein-based biomarkers are widely used in monitoring patients with diagnosed cancer. These biomarkers however, lack specificity for cancer and have poor sensitivity in detecting early recurrences and monitoring therapy effectiveness. Emerging data suggest that the use of circulating tumor DNA (ctDNA) has several advantages over standard biomarkers. Content Following curative-intent surgery for cancer, the presence of ctDNA is highly predictive of early disease recurrence, while in metastatic cancer an early decline in ctDNA following the initiation of treatment is predictive of good outcome. Compared with protein biomarkers, ctDNA provides greater cancer specificity and sensitivity for detecting early recurrent/metastatic disease. Thus, in patients with surgically resected colorectal cancer, multiple studies have shown that ctDNA is superior to carcinoembryonic antigen (CEA) in detecting residual disease and early recurrence. Similarly, in breast cancer, ctDNA was shown...
Clinical utility of circulating tumor DNA in human cancers
memo - Magazine of European Medical Oncology, 2015
The use of circulating tumor DNA (ctDNA) as a prognostic and/or predictive biomarker has been proven in numerous studies. Recent technical advancements have improved sensitivity, specificity, and feasibility of ctDNA detection enabling innovative clinical applications. Besides its potential use as a diagnostic biomarker and the detection of recurrence or minimal residual disease, the most widespread application of the so-called liquid biopsy is real-time monitoring of treatment response and tumor evolution. Since tissue biopsies provide just a static snapshot of the tumor at the time of biopsy and do not necessarily represent the entire tumor genome, a sequential analysis of ctDNA enables an early identification of resistance mechanisms before they become clinically obvious. Furthermore, novel therapy targets that have not been present in available tumor samples might be identified. However, for an actual implementation of the liquid biopsy in clinical practice, it is essential to develop standardized pre-analytical and analytical methodologies and to resolve some outstanding question with respect to origin, biology, and dynamics of ctDNA. In this short review, the clinical utility and existing limitations of ctDNA focusing on monitoring treatment response will be discussed.
Circulating Tumor DNA Assays in Clinical Cancer Research
Journal of the National Cancer Institute, 2018
The importance of circulating free DNA (cfDNA) in cancer clinical research was recognized in 1994 when a mutated RAS gene fragment was detected in a patient's blood sample. Up to 1% of the total circulating DNA in patients with cancer is circulating tumor DNA (ctDNA) that originates from tumor cells. As ctDNA is rapidly cleared from the blood stream and can be obtained by minimally invasive methods, it can be used as a dynamic cancer biomarker for cancer early detection, diagnosis, and treatment monitoring. Despite the potential for clinical use, few ctDNA assays have been cleared or approved by the US Food and Drug Administration. As tools for clinical and translational research, current ctDNA assays face some challenges, and more research is needed to advance use of these assays. On September 29-30, 2016, the Division of Cancer Treatment and Diagnosis at the National Cancer Institute convened a workshop entitled "Circulating Tumor DNA Assays in Clinical Cancer Research&qu...
Journal of Personalized Medicine, 2022
Biomarkers that predict likely response or resistance to specific therapies are critical in personalising treatment for cancer patients. Such biomarkers are now available for an increasing number of anti-cancer therapies, especially targeted therapy and immunotherapy. The gold-standard method for determining predictive biomarkers requires tumour tissue. Obtaining tissue, however, is not always possible and even if possible, the amount or quality of tissue obtained may be inadequate for biomarker analysis. Tumour DNA, however, can be released into the bloodstream, giving rise to what is referred to as circulating tumour DNA (ctDNA). In contrast to tissue, blood can be obtained from effectively all patients in a minimally invasive and safe manner. Other advantages of blood over tissue for biomarker testing include a shorter turn-around time and an ability to perform serial measurements. Furthermore, blood should provide a more complete profile of mutations present in heterogeneous tum...
Circulating Tumor DNA as a Liquid Biopsy for Cancer
Clinical Chemistry, 2014
BACKGROUNDTargeted therapies have markedly changed the treatment of cancer over the past 10 years. However, almost all tumors acquire resistance to systemic treatment as a result of tumor heterogeneity, clonal evolution, and selection. Although genotyping is the most currently used method for categorizing tumors for clinical decisions, tumor tissues provide only a snapshot, or are often difficult to obtain. To overcome these issues, methods are needed for a rapid, cost-effective, and noninvasive identification of biomarkers at various time points during the course of disease. Because cell-free circulating tumor DNA (ctDNA) is a potential surrogate for the entire tumor genome, the use of ctDNA as a liquid biopsy may help to obtain the genetic follow-up data that are urgently needed.CONTENTThis review includes recent studies exploring the diagnostic, prognostic, and predictive potential of ctDNA as a liquid biopsy in cancer. In addition, it covers biological and technical aspects, inc...
Case Reports in Oncology
Liquid biopsy" is an established technique for examining circulating tumor DNA (ctDNA) from a routine blood draw and detecting actionable biomarkers. Nonetheless, ctDNA testing is rarely utilized for patients with newly diagnosed metastatic colorectal cancer (CRC). We report a case in which ctDNA testing uncovered an actionable biomarker that was not detected by comprehensive genomic profiling of tumor tissue. An 81-year-old woman with a remote history of non-Hodgkin's lymphoma presented with primary masses in the ascending colon and sigmoid colon. The ascending colon and sigmoid colon tumors were classified as microsatellite stable (MSS) and mismatch repair proficient (pMMR), and both ctDNA and tissue next-generation sequencing (NGS) from the ascending colon mass were ordered. Because tissue NGS results indicated that the ascending colon tumor was MSS, palliative 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) chemotherapy was started. However, the ctDNA NGS results that arrived after the start of FOLFOX found high microsatellite instability (MSI-H) and mismatch repair deficiency (dMMR) disease with a serine/threonine-protein kinase B-Raf (BRAF V600E) mutation. To treat both her MSS/pMMR ascending colon and sigmoid colon tumors and MSI-H/dMMR metastatic disease, the immunotherapy nivolumab was added to FOLFOX. After 8 months of combined nivolumab and chemotherapy, the patient's metastatic disease had a complete clinical response. This case highlights the complementary role of ctDNA testing for biomarker identification. By performing simultaneous ctDNA testing at the time of diagnosis, an actionable biomarker was discovered that significantly altered this patient's prognosis and treatment options. Orthogonal testing of
BMC cancer, 2017
The presence of circulating cell-free DNA from tumours in blood (ctDNA) is of major importance to those interested in early cancer detection, as well as to those wishing to monitor tumour progression or diagnose the presence of activating mutations to guide treatment. In 2014, the UK Early Cancer Detection Consortium undertook a systematic mapping review of the literature to identify blood-based biomarkers with potential for the development of a non-invasive blood test for cancer screening, and which identified this as a major area of interest. This review builds on the mapping review to expand the ctDNA dataset to examine the best options for the detection of multiple cancer types. The original mapping review was based on comprehensive searches of the electronic databases Medline, Embase, CINAHL, the Cochrane library, and Biosis to obtain relevant literature on blood-based biomarkers for cancer detection in humans (PROSPERO no. CRD42014010827). The abstracts for each paper were rev...
Detection of Circulating Tumor DNA in Solid Tumors
OBM Genetics, 2020
Cancer is characterized by sequential and progressive genetic and epigenetic alterations in key proto-oncogenes and tumor suppressor genes, which ultimately lead to tumor development. Advances in the technology of analysis of molecular mechanisms have increased the efficiency of clinical management of cancer patients. Recent years have witnessed a progressive development in technologies that enable the detection of specific molecular abnormalities associated with various types of solid tumors in body fluids, a process that is globally known as "liquid biopsy". Liquid biopsy is largely based on the circulating free DNA (cfDNA) present in the plasma of healthy individuals and derived either from cell apoptosis or from the active secretion of microvesicles mediated by white blood cells (WBCs). The plasma of cancer patients contains DNA, which is referred to as circulating tumor DNA (ctDNA) and is released by the tumor cells in the form of DNA fragments of various sizes bearing the various types of genetic abnormalities specific to the tumors from which were derived. Sequencing studies conducted with several thousands of cancer patients have revealed that ctDNA accounts for only a fraction of the total DNA, and the size of this fraction varies in relation to tumor burden, tumor site, tumor subtypes, and several other biological properties of the tumor cells. Therefore, the levels of ctDNA are extremely low in several earlystage tumors, requiring highly sensitive methods for the detection of genetic alterations