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.

Genomic alterations after EGFR blockade in patients with RAS wild-type metastatic colorectal cancer: Combined tissue and blood-based analysis from SCRUM-Japan GI-SCREEN and GOZILA.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3528-3528
Author(s):  
Yoshiaki Nakamura ◽  
Riu Yamashita ◽  
Wataru Okamoto ◽  
Yukiya Narita ◽  
Yoshito Komatsu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Metastatic Colorectal Cancer ◽  
Acquired Resistance ◽  
Circulating Tumor Dna ◽  
Integrated Analysis ◽  
Wild Type ◽  
Genomic Alterations ◽  
Kras Mutations ◽  
Copy Numbers ◽  
Oncogenic Pathways

3528 Background: Anti-EGFR therapy (tx) in RAS wild-type (wt) metastatic colorectal cancer (mCRC) induces resistance through acquired genomic alterations. We aimed to define such alterations in Nationwide Cancer Genome Screening Project tissue and blood specimens, using next generation sequencing (NGS). Methods: Tumor specimens in patients (pts) with RAS wt mCRC were obtained from SCRUM-Japan GI-SCREEN (tissue) and GOZILA (circulating tumor DNA [ctDNA] from blood). Genomic alterations were compared using the Oncomine Comprehensive Assay (SCRUM) and Guardant360 (GOZILA), before anti-EGFR tx and after progression. Results: 373 total actionable alterations were identified in 71 pts with available matched tissue and ctDNA; 255 (68%) were acquired after anti-EGFR tx progression. Frequently seen acquired oncogenic alterations included KRAS mutations (27%) and amplifications (amps) of EGFR (41%), CDK6 (24%), BRAF (20%), MYC (17%), MET (14%), PIK3CA (11%), FGFR1 (11%), and KRAS (10%). Fusions of RET, ALK, and FGFR3 were newly acquired in 1-4%. Acquired alterations co-arose in multiple pathways, including the cell cycle, PI3K-AKT, and MAPK, although 29% of pts had none. Acquired mutations were less frequently clonal versus primary mutations (p<0.0001), but clonal acquired mutations were seen in several oncogenes, including EGFR, KRAS, and PIK3CA. A subset of acquired KRAS, MET, CCND2, and EGFR amps had high (>7) adjusted plasma copy numbers (ApCN). Acquired ERBB2 amps were identified in 3 pts (4%) with a median ApCN of 4, one of whom (ApCN=4.2), treated with dual HER2 blockade, progressed after 2 cycles. Conclusions: Our integrated analysis revealed that anti-EGFR tx of pts with RAS WT mCRC led to acquired genomic alterations in multiple oncogenic pathways. Although most acquired alterations were subclonal, a subset of oncogenic alterations had relatively high clonality and ApCN, suggesting potential targets for overcoming acquired resistance to anti-EGFR tx. Early progression in a pt with an ApCN of 4.2 suggests low-level/subclonal acquired alterations may not be effective treatment targets.

RAS Mutations in Circulating Tumor DNA and Clinical Outcomes of Rechallenge Treatment With Anti-EGFR Antibodies in Patients With Metastatic Colorectal Cancer

2020 ◽  
pp. 898-911
Author(s):  
Yu Sunakawa ◽  
Masato Nakamura ◽  
Masahiro Ishizaki ◽  
Masato Kataoka ◽  
Hironaga Satake ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Metastatic Colorectal Cancer ◽  
Clinical Outcomes ◽  
Circulating Tumor Dna ◽  
Wild Type ◽  
Phase Ii Trials ◽  
Ras Mutation ◽  
Ras Mutations ◽  
Ras Status ◽  
Tumor Dna

PURPOSE Several trials have evaluated the efficacy of rechallenge treatment with anti–epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) in patients with metastatic colorectal cancer (mCRC). A recent trial indicated that RAS status in circulating tumor DNA (ctDNA) may potentially predict patients with RAS wild-type mCRC resistant to anti-EGFR mAb who would benefit from rechallenge treatment, and the findings should be further investigated. MATERIAL AND METHODS We enrolled patients whose plasma samples were collected in prospective phase II trials, the JACCRO CC-08 (n = 36) and CC-09 (n = 25), which evaluated rechallenge chemotherapy with anti-EGFR mAb for KRAS wild-type mCRC. RAS in ctDNA was analyzed at the time points of baseline, 8 weeks, and progression using OncoBEAM RAS CRC kit. RESULTS Sixteen patients were enrolled in this study, with a response rate of 0% and a disease control rate (DCR) of 62.5%. RAS mutations were found at baseline in six patients. The DCR was 33% in patients with RAS mutations in ctDNA, whereas it was 80% in patients without RAS mutation at baseline. Patients with RAS mutation at baseline had significantly shorter progression-free survival (PFS) and overall survival (OS) than those without RAS mutation (median PFS, 2.3 v 4.7 months; hazard ratio [HR], 6.2; P = .013; median OS, 3.8 v 16.0 months; HR, 12.4; P = .0028). Six of 10 patients without RAS mutation at baseline acquired RAS mutations at progression. Postprogression survival after rechallenge treatment was numerically shorter in patients with RAS mutation at progression. CONCLUSION RAS status in ctDNA was significantly associated with clinical outcomes in patients with mCRC receiving rechallenge treatment with anti-EGFR mAb. These findings could support the clinical utility of OncoBEAM RAS CRC kits for anti-EGFR mAb rechallenge in RAS wild-type mCRC.

scholarly journals Clinical correlates of circulating cell-free DNA tumor fraction

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256436
Author(s):  
Joerg Bredno ◽  
Jafi Lipson ◽  
Oliver Venn ◽  
Alexander M. Aravanis ◽  
Arash Jamshidi
Keyword(s):  
Colorectal Cancer ◽  
Early Detection ◽  
Metabolic Activity ◽  
Linear Models ◽  
Circulating Tumor Dna ◽  
Cell Free Dna ◽  
Clinical Correlates ◽  
Cancer Early Detection ◽  
Free Dna ◽  
Tumor Dna

Background Oncology applications of cell-free DNA analysis are often limited by the amount of circulating tumor DNA and the fraction of cell-free DNA derived from tumor cells in a blood sample. This circulating tumor fraction varies widely between individuals and cancer types. Clinical factors that influence tumor fraction have not been completely elucidated. Methods and findings Circulating tumor fraction was determined for breast, lung, and colorectal cancer participant samples in the first substudy of the Circulating Cell-free Genome Atlas study (CCGA; NCT02889978; multi-cancer early detection test development) and was related to tumor and patient characteristics. Linear models were created to determine the influence of tumor size combined with mitotic or metabolic activity (as tumor mitotic volume or excessive lesion glycolysis, respectively), histologic type, histologic grade, and lymph node status on tumor fraction. For breast and lung cancer, tumor mitotic volume and excessive lesion glycolysis (primary lesion volume scaled by percentage positive for Ki-67 or PET standardized uptake value minus 1.0, respectively) were the only statistically significant covariates. For colorectal cancer, the surface area of tumors invading beyond the subserosa was the only significant covariate. The models were validated with cases from the second CCGA substudy and show that these clinical correlates of circulating tumor fraction can predict and explain the performance of a multi-cancer early detection test. Conclusions Prognostic clinical variables, including mitotic or metabolic activity and depth of invasion, were identified as correlates of circulating tumor DNA by linear models that relate clinical covariates to tumor fraction. The identified correlates indicate that faster growing tumors have higher tumor fractions. Early cancer detection from assays that analyze cell-free DNA is determined by circulating tumor fraction. Results support that early detection is particularly sensitive for faster growing, aggressive tumors with high mortality, many of which have no available screening today.

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