Analysis of KRAS mutations in circulating tumor DNA and colorectal cancer tissue

2020 ◽  
pp. 1-8
Author(s):  
Yankui Liu ◽  
Longhai Li ◽  
Yu Tian ◽  
Xiao Zhu ◽  
Aijuan Sun ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Circulating Tumor Dna ◽  
Cancer Tissue ◽  
Kras Mutations ◽  
Colorectal Cancer Tissue ◽  
Tumor Dna

INVESTIGATION KRAS MUTATION IN CIRCULATION TUMOR DNA IN DIFFERENT STAGES OF COLORECTAL CANCER

2019 ◽  
Vol 65 (5) ◽  
pp. 701-707
Author(s):  
Vitaliy Shubin ◽  
Yuriy Shelygin ◽  
Sergey Achkasov ◽  
Yevgeniy Rybakov ◽  
Aleksey Ponomarenko ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Plasma Volume ◽  
Kras Mutation ◽  
Stage Iv ◽  
Circulating Tumor Dna ◽  
Stage Ii ◽  
Kras Gene ◽  
Kras Mutations ◽  
Droplet Pcr ◽  
Tumor Dna

To determine mutations in the plasma KRAS gene in patients with colorectal cancer was the aim of this study. The material was obtained from 44 patients with colorectal cancer of different stages (T1-4N0-2bM0-1c). Plasma for the presence of KRAS gene mutation in circulating tumor DNA was investigated using digital droplet polymerase chain reaction (PCR). KRAS mutations in circulating tumor DNA isolated from 1 ml of plasma were detected in 13 (30%) patients with cancer of different stages. Of these, with stage II, there were 3 patients, with III - 5 and with IV - 5. Patients who did not have mutations in 1 ml of plasma were analyzed for mutations of KRAS in circulating tumor DNA isolated from 3 ml of plasma. Five more patients with KRAS mutations were found with II and III stages. The highest concentrations of circulating tumor DNA with KRAS mutation were found in patients with stage IV. The increase in plasma volume to 3 ml did not lead to the identification of mutations in I stage. This study showed that digital droplet PCR allows identification of circulating tumor DNA with the KRAS mutations in patients with stage II-IV of colon cancer. The results can be used to determine the degree of aggressiveness of the tumor at different stages of the disease, but not the 1st, and it is recommended to use a plasma volume of at least 3 ml.

Plasma cell-free DNA and fraction of circulating KRAS mutations as prognostic in patients with metastatic colorectal cancer.

2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 490-490 ◽  
Author(s):  
David Sefrioui ◽  
Nasrin Vasseur ◽  
Richard Sesboüé ◽  
France Blanchard ◽  
Alice Oden-Gangloff ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Metastatic Colorectal Cancer ◽  
Plasma Cell ◽  
Circulating Tumor Dna ◽  
Dna Fragments ◽  
Wild Type ◽  
Kras Mutations ◽  
Cell Free Dna ◽  
Free Dna ◽  
Tumor Dna

490 Background: It has been suggested that detection of circulating tumor DNA may be relevant in patients with metastatic colorectal cancer (mCRC). The main objective of the present study was to evaluate a method based on the TaqMan Mutation Detection Assay (TMDA) for the detection of circulating KRAS mutations in mCRC patients. Moreover, we also investigated the prognostic impact of the plasma cell-free DNA and the fraction of circulating KRAS mutations. Methods: The study was conducted from April to July 2013 and plasma samples were prospectively collected in a series of 35 mCRC patients treated with chemotherapy (CT). QIAamp Circulating Nucleic Acid kit was used for DNA extraction and Quant-iT High Sensitivity dsDNA Assay for cf-DNA quantification. Detection of circulating tumor DNA was based on the KRAS mutations detected in tumour and was performed in plasma by the castPCR Technology TMDA. Response to CT was assessed according to RECIST criteria. The results of plasma cf-DNA and level of mutant DNA fragments were correlated with response and 3-months survival. Results: We isolated and quantified plasma cf-DNA in all patients with a mean concentration of 106 ng/mL. Among them, 18 were wild-type and 17 mutated for KRAS in the tumour. Detection of circulating KRAS mutations was performed with TMDA in 23 patients (10 KRAS wild-type and 13 KRAS mutated). The sensitivity was 62% (8/13) and specificity 100% (0/10) with a level of circulating mutant DNA fragments ranging from 0 to 29%. Plasma cf-DNA and level of circulating mutant DNA were both significantly correlated with the 3-months survival (mean 36 versus 524 ng/mL, p=0.0015 and 2% versus 29%, p<0.0001). There was a non significant trend for response to CT (respectively p=0.14 and p=0.12). Conclusions: TMDA method is a simple, accurate and non-invasive tool for the detection of circulating tumor DNA. Our preliminary results also suggest that plasma cf-DNA and fraction of mutant DNA fragments could be prognostic markers in mCRC patients.

Specificity of methylated BCAT1 and IKZF1 for colorectal cancer.

2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 580-580
Author(s):  
Erin L. Symonds ◽  
Beibei Yao ◽  
Susanne Kartin Pedersen ◽  
David Murray ◽  
Graeme P Young
Keyword(s):  
Colorectal Cancer ◽  
Oesophageal Cancer ◽  
Circulating Tumor Dna ◽  
Cancer Tissue ◽  
Neoplastic Tissue ◽  
Invasive Adenocarcinoma ◽  
Screening And Surveillance ◽  
Adenocarcinoma Of The Prostate ◽  
Cancer Tissues ◽  
Tumor Dna

580 Background: Methylated BCAT1 and IKZF1 are useful circulating tumor DNA (ctDNA) biomarkers for detection and following the course of colorectal cancer (CRC). This study aimed to determine the specificity of methylated BCAT1/ IKZF1 for CRC detection by assaying specimens from patients with other adenocarcinomas. Methods: Blood was collected from patients with invasive adenocarcinoma of the prostate (n = 32), breast (16), oesophagus (15) or colon/rectum (212), prior to any treatment or resection, and from 245 clinically assessed controls with no known prior or current adenocarcinoma. Biopsies were collected from cancer tissue and adjacent non-neoplastic tissue either prior to treatment or at surgery from 9 prostate, 26 breast, 6 oesophagus, 15 CRC cases. All specimens were assayed for methylated BCAT1 and IKZF1 DNA. Calculation of positivity rates: tissue, the proportion of tissue cases with ≥ 5% methylation; blood, the proportion of cases with any detectable signal of either marker. Results: ctDNA positivity rates were significantly higher in CRC (126/212, 59.4%, 95% CI: 52.5 - 66.1) and oesophageal cancer (6/16, 33.3%, 11.0 - 58.7) cases only compared to controls (16/245, 6.5%, 3.8 - 10.4; p < 0.01). ctDNA was more likely to be positive in late stage cancers, although only significant for CRC, Table. Cancer tissue positivity rates were: CRC, 15/15, 100% (96.4 - 100); oesophageal, 5/6, 83.3% (35.9 - 99.6); prostate, 4/9, 44.4% (13.7 - 78.8); breast, 5/26, 19.2% (6.6 - 39.4). All cancer tissues had significantly higher methylation levels than the adjacent tissue (Chi2 test, p >0.05). Conclusions: Only colorectal and oesophageal cancer patients had significantly higher ctDNA positivity rates (using methylated BCAT1/IKZF1) compared to controls. This was also reflected in a higher proportion of cases showing methylation in the cancer tissue. The methylated BCAT1/IKZF1 blood test should be investigated further as a screening and surveillance tool for oesophageal cancer. [Table: see text]

scholarly journals KRAS A146 Mutations Are Associated With Distinct Clinical Behavior in Patients With Colorectal Liver Metastases

2021 ◽  
pp. 1758-1767
Author(s):  
Iris van 't Erve ◽  
Nina J. Wesdorp ◽  
Jamie E. Medina ◽  
Leonardo Ferreira ◽  
Alessandro Leal ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Kras Mutation ◽  
Clinical Care ◽  
Prospective Trial ◽  
Predictive Biomarker ◽  
Circulating Tumor Dna ◽  
Kras Mutations ◽  
Molecular Subgroup ◽  
Computed Tomography Images ◽  
Tumor Dna

PURPOSE Somatic KRAS mutations occur in approximately half of the patients with metastatic colorectal cancer (mCRC). Biologic tumor characteristics differ on the basis of the KRAS mutation variant. KRAS mutations are known to influence patient prognosis and are used as predictive biomarker for treatment decisions. This study examined clinical features of patients with mCRC with a somatic mutation in KRAS G12, G13, Q61, K117, or A146. METHODS A total of 419 patients with colorectal cancer with initially unresectable liver-limited metastases, who participated in a multicenter prospective trial, were evaluated for tumor tissue KRAS mutation status. For the subgroup of patients who carried a KRAS mutation and were treated with bevacizumab and doublet or triplet chemotherapy (N = 156), pretreatment circulating tumor DNA levels were analyzed, and total tumor volume (TTV) was quantified on the pretreatment computed tomography images. RESULTS Most patients carried a KRAS G12 mutation (N = 112), followed by mutations in G13 (N = 15), A146 (N = 12), Q61 (N = 9), and K117 (N = 5). High plasma circulating tumor DNA levels were observed for patients carrying a KRAS A146 mutation versus those with a KRAS G12 mutation, with median mutant allele frequencies of 48% versus 19%, respectively. Radiologic TTV revealed this difference to be associated with a higher tumor load in patients harboring a KRAS A146 mutation (median TTV 672 cm3 [A146] v 74 cm3 [G12], P = .036). Moreover, KRAS A146 mutation carriers showed inferior overall survival compared with patients with mutations in KRAS G12 (median 10.7 v 26.4 months; hazard ratio = 2.5; P = .003). CONCLUSION Patients with mCRC with a KRAS A146 mutation represent a distinct molecular subgroup of patients with higher tumor burden and worse clinical outcomes, who might benefit from more intensive treatments. These results highlight the importance of testing colorectal cancer for all KRAS mutations in routine clinical care.

scholarly journals High sensitivity of both sequencing and real-time PCR analysis of KRAS mutations in colorectal cancer tissue

2009 ◽  
Vol 14 (8) ◽  
pp. 2122-2131 ◽  
Author(s):  
Jolien Tol ◽  
Jeroen R. Dijkstra ◽  
Marianne E. Vink-Börger ◽  
Iris D. Nagtegaal ◽  
Cornelis J.A. Punt ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Real Time ◽  
Real Time Pcr ◽  
High Sensitivity ◽  
Pcr Analysis ◽  
Cancer Tissue ◽  
Kras Mutations ◽  
Colorectal Cancer Tissue

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.

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