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Updated: Mar 22, 2026
Detection of Cell-Free DNA in Blood Plasma Samples of Cancer Patients
Published on: September 9, 2020
Cell-free circulating tumor DNA in cancer
Zhen Qin1,2, Vladimir A Ljubimov3, Cuiqi Zhou1
1Department of Medicine, Cedars-Sinai Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, 90048, USA.
Abstract:
Cancer is a common cause of death worldwide. Despite significant advances in cancer treatments, the morbidity and mortality are still enormous. Tumor heterogeneity, especially intratumoral heterogeneity, is a significant reason underlying difficulties in tumor treatment and failure of a number of current therapeutic modalities, even of molecularly targeted therapies. The development of a virtually noninvasive "liquid biopsy" from the blood has been attempted to characterize tumor heterogeneity. This review focuses on cell-free circulating tumor DNA (ctDNA) in the bloodstream as a versatile biomarker. ctDNA analysis is an evolving field with many new methods being developed and optimized to be able to successfully extract and analyze ctDNA, which has vast clinical applications. ctDNA has the potential to accurately genotype the tumor and identify personalized genetic and epigenetic alterations of the entire tumor. In addition, ctDNA has the potential to accurately monitor tumor burden and treatment response, while also being able to monitor minimal residual disease, reducing the need for harmful adjuvant chemotherapy and allowing more rapid detection of relapse. There are still many challenges that need to be overcome prior to this biomarker getting wide adoption in the clinical world, including optimization, standardization, and large multicenter trials.
Insights
Liquid biopsies using cell-free circulating tumor DNA (ctDNA) offer a noninvasive way to track cancer. ctDNA analysis shows promise for personalized treatment and early relapse detection, despite ongoing challenges.
Area of Science:
- Oncology
- Molecular Biology
- Biomarker Discovery
Background:
- Cancer remains a leading cause of death globally, with significant morbidity and mortality.
- Intratumoral heterogeneity poses a major challenge to effective cancer treatment and targeted therapies.
- Current diagnostic and monitoring methods often require invasive procedures.
Purpose of the Study:
- To review the potential of cell-free circulating tumor DNA (ctDNA) as a biomarker for characterizing tumor heterogeneity.
- To explore the clinical applications of ctDNA analysis in cancer management.
- To discuss the challenges and future directions for the clinical adoption of ctDNA biomarkers.
Main Methods:
- Review of current literature on ctDNA analysis and its applications.
- Focus on methods for extracting and analyzing ctDNA from blood samples.
- Discussion of the potential of ctDNA to genotype tumors and monitor disease progression.
Main Results:
- ctDNA analysis enables noninvasive characterization of tumor genetic and epigenetic alterations.
- ctDNA can accurately monitor tumor burden, treatment response, and minimal residual disease.
- Early detection of relapse through ctDNA monitoring can guide treatment decisions.
Conclusions:
- ctDNA is a versatile biomarker with vast potential in personalized oncology.
- Further optimization, standardization, and multicenter trials are necessary for widespread clinical implementation.
- ctDNA analysis may reduce the need for aggressive therapies and improve patient outcomes.
