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Updated: May 12, 2026
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Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
Published on: June 8, 2019
A Noninvasive Circulating Tumor DNA Methylation Classifier to Identify Benign Pulmonary Nodules
Qiaomei Guo1,2,3,4, Chaoqiang Deng5,6,7, Xufeng Pan8
1Department of Laboratory Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Summary
A new ctDNA methylation test improves pulmonary nodule evaluation by reducing false positives. This biomarker aids in lung cancer risk stratification, potentially decreasing unnecessary invasive procedures.
Area of Science:
- Biomarker discovery and development
- Molecular diagnostics
- Computational biology
Background:
- Low-dose computed tomography (LDCT) for pulmonary nodules has a high false-positive rate.
- Circulating tumor DNA (ctDNA) methylation is a promising biomarker, but fragmented ctDNA poses detection challenges.
Purpose of the Study:
- To develop a novel method for sensitive ctDNA methylation detection.
- To create a classifier for pulmonary nodule risk stratification using ctDNA methylation.
Main Methods:
- Developed Single-Strand Amplification Methylation-Targeted Sequencing (SAMT-Seq) for fragmented ctDNA.
- Identified and selected 30 lung cancer-specific methylation markers.
- Validated a Gaussian process classifier in independent cohorts.
Main Results:
- SAMT-Seq showed superior sensitivity and efficiency over standard methods.
- The 30-marker classifier achieved high AUCs (0.95, 0.95, 0.92) across cohorts.
- The classifier demonstrated high specificity (up to 100%) across various nodule types and sizes.
Conclusions:
- Developed a high-specificity ctDNA methylation classifier for pulmonary nodule risk stratification.
- The classifier shows potential to reduce unnecessary invasive procedures.
- Clinical performance is being evaluated in an ongoing prospective study.
