scholarly journals High-Accuracy Determination of Microsatellite Instability Compatible with Liquid Biopsies

2020 ◽  
Vol 66 (4) ◽  
pp. 606-613 ◽  
Author(s):  
Amanda Bortolini Silveira ◽  
François-Clément Bidard ◽  
Amélie Kasperek ◽  
Samia Melaabi ◽  
Marie-Laure Tanguy ◽  
...  
Keyword(s):  
Microsatellite Instability ◽  
Large Scale ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Diagnostic Tools ◽  
Tumor Biomarker ◽  
Analytical Sensitivity ◽  
Liquid Biopsies ◽  
Tumor Dna ◽  
Large Scale Screening

Abstract Background Microsatellite instability (MSI) has recently emerged as a predictive pan-tumor biomarker of immunotherapy efficacy, stimulating the development of diagnostic tools compatible with large-scale screening of patients. In this context, noninvasive detection of MSI from circulating tumor DNA stands as a promising diagnostic and posttreatment monitoring tool. Methods We developed drop-off droplet-digital PCR (ddPCR) assays targeting BAT-26, activin A receptor type 2A (ACVR2A), and defensin beta 105A/B (DEFB105A/B) microsatellite markers. Performances of the assays were measured on reconstitution experiments of various mutant allelic fractions, on 185 tumor samples with known MSI status, and on 72 blood samples collected from 42 patients with advanced colorectal or endometrial cancers before and/or during therapy. Results The 3 ddPCR assays reached analytical sensitivity <0.1% variant allelic frequency and could reliably detect and quantify MSI in both tumor and body fluid samples. High concordance between MSI status determination by the three-marker ddPCR test and the reference pentaplex method were observed (100% for colorectal tumors and 93% for other tumor types). Moreover, the 3 assays showed correlations with r ≥ 0.99 with other circulating tumor DNA markers and their dynamic during treatment correlated well with clinical response. Conclusions This innovative approach for MSI detection provides a noninvasive, cost-effective, and fast diagnostic tool, well suited for large-scale screening of patients that may benefit from immunotherapy agents, as well as for monitoring treatment responses.

scholarly journals Plasma Circulating Tumor DNA Levels for the Monitoring of Melanoma Patients: Landscape of Available Technologies and Clinical Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Benoit Busser ◽  
Julien Lupo ◽  
Lucie Sancey ◽  
Stéphane Mouret ◽  
Patrice Faure ◽  
...  
Keyword(s):  
Acquired Resistance ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Clinical Applications ◽  
Molecular Heterogeneity ◽  
Liquid Biopsies ◽  
Melanoma Patients ◽  
Ctdna Analysis ◽  
Next Generation Sequencing Ngs ◽  
Tumor Dna

Melanoma is a cutaneous cancer with an increasing worldwide prevalence and high mortality due to unresectable or metastatic stages. Mutations inBRAF,NRAS, orKITare present in more than 60% of melanoma cases, but a useful blood-based biomarker for the clinical monitoring of melanoma patients is still lacking. Thus, the analysis of circulating tumor cells (CTCs) and/or cell-free circulating tumor DNA (ctDNA) analysis from blood (liquid biopsies) appears to be a promising noninvasive, repeatable, and systemic sampling tool for detecting and monitoring melanoma. Here, we review the molecular biology-based strategies used for ctDNA quantification in melanoma patients, as well as their main clinical applications. Droplet digital PCR (ddPCR) and next generation sequencing (NGS) technologies appear to be two versatile and complementary strategies to study rare variant mutations for the detection and monitoring of melanoma progression. Among the different clinical uses of ctDNA, we highlight the assessment of molecular heterogeneity and the identification of genetic determinants for targeted therapy as well as the analysis of acquired resistance. Importantly, ctDNA quantification might also be a novel biomarker with a prognostic value for melanoma patients.

scholarly journals Circulating Tumor DNA as a Sensitive Marker in Patients Undergoing Irreversible Electroporation for Pancreatic Cancer

2018 ◽  
Vol 47 (4) ◽  
pp. 1556-1564 ◽  
Author(s):  
Mao Lin ◽  
Mohammed Alnaggar ◽  
Shuzhen Liang ◽  
Jibing Chen ◽  
Kecheng Xu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Overall Survival ◽  
Irreversible Electroporation ◽  
Circulating Tumor Dna ◽  
Carbohydrate Antigen ◽  
Ductal Adenocarcinoma ◽  
Diagnostic Tools ◽  
Tumor Biomarker ◽  
Monitoring Treatment ◽  
Tumor Dna

Background/Aims: Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced stage, resulting in extremely poor 5-year survival. Late diagnosis of PDAC is mainly due to lack of a reliable method of early detection. Carbohydrate antigen (CA) 19-9 is often used as a tumor biomarker in PDAC; however, the test lacks sensitivity and specificity. Therefore, new sensitive and minimally invasive diagnostic tools are required to detect pancreatic cancer. Methods: Here, we investigated circulating tumor DNA (ctDNA) which contained KRAS-mutated as a potential diagnostic tool for PDAC patients who underwent irreversible electroporation (IRE). We used droplet digital polymerase chain reaction (ddPCR) to detect the expression of KRAS-mutated genes in plasma samples of 65 PDAC patients who underwent IRE. Results: In these 65 cases, ctDNA was detected in 20 (29.2%) samples. The median overall survival (OS) was 11.4 months with ctDNA+ patients and 14.3 months for ctDNA- patients. ctDNA+ patients had a obviously poorer prognosis associated to overall survival (P < 0.001). Conclusion: Our results suggested that the existence of ctDNA was a predictor of survival for PDAC patients. Therefore, ctDNA may be a new sensitive biomarker for monitoring treatment outcome in PDAC.

scholarly journals Detection of Microsatellite Instability via Circulating Tumor DNA and Response to Immunotherapy in Metastatic Castration-Resistant Prostate Cancer: A Case Series

2021 ◽  
pp. 190-196
Author(s):  
Deepak Ravindranathan ◽  
Greta Anne Russler ◽  
Lauren Yantorni ◽  
Leylah M. Drusbosky ◽  
Mehmet Asim Bilen
Keyword(s):  
Prostate Cancer ◽  
Microsatellite Instability ◽  
Case Series ◽  
Circulating Tumor Dna ◽  
Castration Resistant Prostate Cancer ◽  
Liquid Biopsies ◽  
Castration Resistant ◽  
Before And After ◽  
Initiation Of Therapy ◽  
Tumor Dna

Pembrolizumab has been approved by the US Food and Drug Administration for the treatment of metastatic or unresectable solid tumors that are microsatellite instability-high (MSI-H) or mismatch repair deficient. Blood-based circulating tumor DNA (ctDNA) assays have been validated to identify tumors with MSI-H status without the need for tissue biopsy. We report 2 patients with metastatic castration-resistant prostate cancer (mCRPC) who had prior treatment with multiple lines of therapy and underwent ctDNA testing, which detected MSI-H status. Both patients were treated with pembrolizumab, resulting in an excellent clinical response measured with liquid biopsies before and after initiation of therapy, which demonstrated a significant reduction in somatic-variant allele frequency in addition to a decrease in prostate serum antigen levels.

Greater than two coexisting mutations in KRAS and NRAS identified in the circulating tumor DNA fraction of liquid biopsies by NGS and confirmed with ddPCR.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15563-e15563
Author(s):  
Hala Boulos ◽  
Robert Tell ◽  
Nike Beaubier ◽  
Richard Blidner
Keyword(s):  
Liquid Biopsy ◽  
Detection Threshold ◽  
Treatment Resistance ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Precision Oncology ◽  
Single Nucleotide Variants ◽  
Liquid Biopsies ◽  
Low Frequencies ◽  
Tumor Dna

e15563 Background: Liquid biopsies are increasingly utilized as a non-invasive tool in precision oncology to assess tumor mutational profiles in order to select targeted therapies, detect treatment resistance, and monitor disease progression in cancer patients. Additionally, liquid biopsies may provide a more comprehensive representation of tumor heterogeneity than standard tissue biopsies. However, limitations such as scarcity of circulating tumor DNA (ctDNA) and/or variants at low frequencies can be technically challenging to detect by next-generation sequencing (NGS) assays. Here, we use NGS to detect greater than two KRAS/NRAS mutations coexisting in single samples at low variant allele frequencies (VAFs). Methods: The Tempus xF liquid biopsy NGS assay is designed to detect actionable oncologic targets spanning 105 genes in plasma. The assay was validated to reliably detect single-nucleotide variants at 0.25% VAF, indels and copy number variants at 0.5% VAF, and fusions at 1% VAF with 96.2%-100% specificity and 97.4%-100% sensitivity. Pre-designed digital PCR assays were modified to measure 10ng of cell-free DNA (cfDNA) on a droplet-digital PCR (ddPCR) platform. Results: Overall, we report 100% positive predictive value and high correlation between ddPCR results and xF VAF, as well as in individual variants, such as KRAS G12D. Unexpectedly, we detected more than two coexisting KRAS/NRAS mutations at a low VAF in the plasma samples. To orthogonally confirm these results, ddPCR was deployed to independently measure the presence of each cfDNA variant with a sensitivity of 0.09% VAF. Subsequent ddPCR analysis of all targeted variants were concordant with NGS results. Conclusions: The occurrence of multiple KRAS and NRAS mutations in a single sample is quite uncommon and may be falsely interpreted as an NGS artifact. However, verification of this phenomenon by ddPCR confirmed the validity of the NGS liquid biopsy approach. These results highlight the capability of the Tempus xF assay to detect low-frequency variants, including those that fall below the validated detection threshold, which is essential for the diagnosis of early disease.

Clinical applications of circulating tumor DNA in monitoring breast cancer drug resistance

2020 ◽  
Vol 16 (34) ◽  
pp. 2863-2878
Author(s):  
Yang Liu ◽  
Qian Du ◽  
Dan Sun ◽  
Ruiying Han ◽  
Mengmeng Teng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Resistance Mechanisms ◽  
Clinical Applications ◽  
Current Status ◽  
Cancer Drug ◽  
Genomic Alteration ◽  
Tumor Dna

Breast cancer is one of the leading causes of cancer-related deaths in women worldwide. Unfortunately, treatments often fail because of the development of drug resistance, the underlying mechanisms of which remain unclear. Circulating tumor DNA (ctDNA) is free DNA released into the blood by necrosis, apoptosis or direct secretion by tumor cells. In contrast to repeated, highly invasive tumor biopsies, ctDNA reflects all molecular alterations of tumors dynamically and captures both spatial and temporal tumor heterogeneity. Highly sensitive technologies, including personalized digital PCR and deep sequencing, make it possible to monitor response to therapies, predict drug resistance and tailor treatment regimens by identifying the genomic alteration profile of ctDNA, thereby achieving precision medicine. This review focuses on the current status of ctDNA biology, the technologies used to detect ctDNA and the potential clinical applications of identifying drug resistance mechanisms by detecting tumor-specific genomic alterations in breast cancer.

scholarly journals Circulating tumor DNA is detectable in canine histiocytic sarcoma, oral malignant melanoma, and multicentric lymphoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anaïs Prouteau ◽  
Jérôme Alexandre Denis ◽  
Pauline De Fornel ◽  
Edouard Cadieu ◽  
Thomas Derrien ◽  
...  
Keyword(s):  
Residual Disease ◽  
Specific Antigen ◽  
Point Mutations ◽  
Antigen Receptor ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Histiocytic Sarcoma ◽  
Oncology Research ◽  
Tumor Dna

AbstractCirculating tumor DNA (ctDNA) has become an attractive biomarker in human oncology, and its use may be informative in canine cancer. Thus, we used droplet digital PCR or PCR for antigen receptor rearrangement, to explore tumor-specific point mutations, copy number alterations, and chromosomal rearrangements in the plasma of cancer-affected dogs. We detected ctDNA in 21/23 (91.3%) of histiocytic sarcoma (HS), 2/8 (25%) of oral melanoma, and 12/13 (92.3%) of lymphoma cases. The utility of ctDNA in diagnosing HS was explored in 133 dogs, including 49 with HS, and the screening of recurrent PTPN11 mutations in plasma had a specificity of 98.8% and a sensitivity between 42.8 and 77% according to the clinical presentation of HS. Sensitivity was greater in visceral forms and especially related to pulmonary location. Follow-up of four dogs by targeting lymphoma-specific antigen receptor rearrangement in plasma showed that minimal residual disease detection was concordant with clinical evaluation and treatment response. Thus, our study shows that ctDNA is detectable in the plasma of cancer-affected dogs and is a promising biomarker for diagnosis and clinical follow-up. ctDNA detection appears to be useful in comparative oncology research due to growing interest in the study of natural canine tumors and exploration of new therapies.

scholarly journals Small EVs-Associated DNA as Complementary Biomarker to Circulating Tumor DNA in Plasma of Metastatic Colorectal Cancer Patients

2021 ◽  
Vol 14 (2) ◽  
pp. 128
Author(s):  
Silvia Galbiati ◽  
Francesco Damin ◽  
Dario Brambilla ◽  
Lucia Ferraro ◽  
Nadia Soriani ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Metastatic Colorectal Cancer ◽  
Cancer Patients ◽  
Digital Pcr ◽  
Extracellular Vesicle ◽  
Circulating Tumor Dna ◽  
Mutation Status ◽  
Promising Practice ◽  
Colorectal Cancer Patients ◽  
Tumor Dna

It is widely accepted that assessing circular tumor DNA (ctDNA) in the plasma of cancer patients is a promising practice to evaluate somatic mutations from solid tumors noninvasively. Recently, it was reported that isolation of extracellular vesicles improves the detection of mutant DNA from plasma in metastatic patients; however, no consensus on the presence of dsDNA in exosomes has been reached yet. We analyzed small extracellular vesicle (sEV)-associated DNA of eleven metastatic colorectal cancer (mCRC) patients and compared the results obtained by microarray and droplet digital PCR (ddPCR) to those reported on the ctDNA fraction. We detected the same mutations found in tissue biopsies and ctDNA in all samples but, unexpectedly, in one sample, we found a KRAS mutation that was not identified either in ctDNA or tissue biopsy. Furthermore, to assess the exact location of sEV-associated DNA (outside or inside the vesicle), we treated with DNase I sEVs isolated with three different methodologies. We found that the DNA inside the vesicles is only a small fraction of that surrounding the vesicles. Its amount seems to correlate with the total amount of circulating tumor DNA. The results obtained in our experimental setting suggest that integrating ctDNA and sEV-associated DNA in mCRC patient management could provide a complete real-time assessment of the cancer mutation status.

scholarly journals Detection of tumor-derived extracellular vesicles in plasma from patients with solid cancer

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Silvia R. Vitale ◽  
Jean A. Helmijr ◽  
Marjolein Gerritsen ◽  
Hicret Coban ◽  
Lisanne F. van Dessel ◽  
...  
Keyword(s):  
Cell Lines ◽  
Extracellular Vesicles ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Solid Cancer ◽  
Expression Levels ◽  
Healthy Donors ◽  
Spin Column ◽  
High Concordance ◽  
Tumor Dna

Abstract Background Extracellular vesicles (EVs) are actively secreted by cells into body fluids and contain nucleic acids of the cells they originate from. The goal of this study was to detect circulating tumor-derived EVs (ctEVs) by mutant mRNA transcripts (EV-RNA) in plasma of patients with solid cancers and compare the occurrence of ctEVs with circulating tumor DNA (ctDNA) in cell-free DNA (cfDNA). Methods For this purpose, blood from 20 patients and 15 healthy blood donors (HBDs) was collected in different preservation tubes (EDTA, BCT, CellSave) and processed into plasma within 24 h from venipuncture. EVs were isolated with the ExoEasy protocol from this plasma and from conditioned medium of 6 cancer cell lines and characterized according to MISEV2018-guidelines. RNA from EVs was isolated with the ExoRNeasy protocol and evaluated for transcript expression levels of 96 genes by RT-qPCR and genotyped by digital PCR. Results Our workflow applied on cell lines revealed a high concordance between cellular mRNA and EV-RNA in expression levels as well as variant allele frequencies for PIK3CA, KRAS and BRAF. Plasma CD9-positive EV and GAPDH EV-RNA levels were significantly different between the preservation tubes. The workflow detected only ctEVs with mutant transcripts in plasma of patients with high amounts (> 20%) of circulating tumor DNA (ctDNA). Expression profiling showed that the EVs from patients resemble healthy donors more than tumor cell lines supporting that most EVs are derived from healthy tissue. Conclusions We provide a workflow for ctEV detection by spin column-based generic isolation of EVs and PCR-based measurement of gene expression and mutant transcripts in EV-RNA derived from cancer patients’ blood plasma. This workflow, however, detected tumor-specific mutations in blood less often in EV-RNA than in cfDNA.

scholarly journals Diagnostic accuracy of droplet digital PCR for detection of EGFR T790M mutation in circulating tumor DNA

2018 ◽  
Vol Volume 10 ◽  
pp. 1209-1218 ◽  
Author(s):  
Rui Zhang ◽  
Bojiang Chen ◽  
Xiang Tong ◽  
Ye Wang ◽  
Chengdi Wang ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Droplet Digital Pcr ◽  
T790m Mutation ◽  
Tumor Dna ◽  
Egfr T790m

scholarly journals Detection of KRAS Mutations in Circulating Tumor DNA by Digital PCR in Early Stages of Pancreatic Cancer

2016 ◽  
Vol 62 (11) ◽  
pp. 1482-1491 ◽  
Author(s):  
Nora Brychta ◽  
Thomas Krahn ◽  
Oliver von Ahsen
Keyword(s):  
Pancreatic Cancer ◽  
Early Stage ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Surgical Removal ◽  
Plasma Samples ◽  
Kras Mutations ◽  
Detection Rates ◽  
Early Stages ◽  
Tumor Dna

Abstract BACKGROUND Since surgical removal remains the only cure for pancreatic cancer, early detection is of utmost importance. Circulating biomarkers have potential as diagnostic tool for pancreatic cancer, which typically causes clinical symptoms only in advanced stage. Because of their high prevalence in pancreatic cancer, KRAS proto-oncogene, GTPase [KRAS (previous name: Kirsten rat sarcoma viral oncogene homolog)] mutations may be used to identify tumor-derived circulating plasma DNA. Here we tested the diagnostic sensitivity of chip based digital PCR for the detection of KRAS mutations in circulating tumor DNA (ctDNA) in early stage pancreatic cancer. METHODS We analyzed matched plasma (2 mL) and tumor samples from 50 patients with pancreatic cancer. Early stages (I and II) were predominant (41/50) in this cohort. DNA was extracted from tumor and plasma samples and tested for the common codon 12 mutations G12D, G12V, and G12C by chip-based digital PCR. RESULTS We identified KRAS mutations in 72% of the tumors. 44% of the tumors were positive for G12D, 20% for G12V, and 10% for G12C. One tumor was positive for G12D and G12V. Analysis of the mutations in matched plasma samples revealed detection rates of 36% for G12D, 50% for G12V, and 0% for G12C. The detection appeared to be correlated with total number of tumor cells in the primary tumor. No KRAS mutations were detected in 20 samples of healthy control plasma. CONCLUSIONS Our results support further evaluation of tumor specific mutations as early diagnostic biomarkers using plasma samples as liquid biopsy.

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