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Updated: Feb 14, 2026
06:19
Isolation of Circulating Tumor Cells in an Orthotopic Mouse Model of Colorectal Cancer
Published on: July 18, 2017
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RAS mutation analysis in circulating tumor DNA from patients with metastatic colorectal cancer: the AGEO RASANC
J B Bachet1, O Bouché2, J Taieb3
1Sorbonne Universités, UPMC Université, Paris; Université Sorbonne Paris Cité, INSERM UMR-S1147 MEPPOT, CNRS SNC5014, Centre Universitaire des Saints-Pères, Equipe Labellisée Ligue Nationale Contre le Cancer, Paris; Department of Hepato-Gastroenterology, Groupe Hospitalier Pitié Salpêtrière, Paris; AGEO (Association des Gastroentérologues Oncologues), Paris.
Summary
Plasma RAS testing offers a faster alternative to tissue analysis for metastatic colorectal cancer patients, significantly reducing turnaround time for treatment decisions and clinical trial eligibility.
Area of Science:
- Oncology
- Molecular Diagnostics
- Genetics
Background:
- RAS mutations are critical biomarkers for anti-EGFR therapy in metastatic colorectal cancer (mCRC).
- Current methods for RAS mutation detection in tumor tissue are time-consuming, delaying treatment and trial enrollment.
- Circulating tumor DNA (ctDNA) analysis presents a potential solution for rapid RAS status determination.
Purpose of the Study:
- To compare the concordance and accuracy of RAS mutation detection in plasma (ctDNA) versus tumor tissue.
- To validate plasma-based RAS testing as a viable alternative for routine clinical use in mCRC patients.
Main Methods:
- A prospective, multicenter cohort study involving 425 chemotherapy-naive mCRC patients.
- Centralized plasma analysis using next-generation sequencing (NGS) and methylation-specific digital PCR.
- Parallel local tumor tissue analysis according to routine clinical practice.
Main Results:
- High concordance (κ=0.71) and accuracy (85.2%) between plasma and tissue RAS testing in the overall cohort.
- Significantly improved concordance (κ=0.89) and accuracy (94.8%) in patients with detectable ctDNA.
- Plasma testing demonstrated high accuracy (97%) when combining NGS and methylation biomarkers in patients with liver metastases.
Conclusions:
- Plasma-based RAS mutation analysis shows excellent concordance with tumor tissue analysis in mCRC patients.
- ctDNA testing is a validated and efficient method for determining RAS status, especially in patients with liver metastases.
- This approach can expedite treatment decisions and facilitate timely enrollment in clinical trials.
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