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Updated: Oct 27, 2025
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
Published on: June 8, 2019
Signed in Blood: Circulating Tumor DNA in Cancer Diagnosis, Treatment and Screening
Jacob J Adashek1, Filip Janku2, Razelle Kurzrock3
1Department of Internal Medicine, University of South Florida, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33606, USA.
Abstract:
With the addition of molecular testing to the oncologist's diagnostic toolbox, patients have benefitted from the successes of gene- and immune-directed therapies. These therapies are often most effective when administered to the subset of malignancies harboring the target identified by molecular testing. An important advance in the application of molecular testing is the liquid biopsy, wherein circulating tumor DNA (ctDNA) is analyzed for point mutations, copy number alterations, and amplifications by polymerase chain reaction (PCR) and/or next-generation sequencing (NGS). The advantages of evaluating ctDNA over tissue DNA include (i) ctDNA requires only a tube of blood, rather than an invasive biopsy, (ii) ctDNA can plausibly reflect DNA shedding from multiple metastatic sites while tissue DNA reflects only the piece of tissue biopsied, and (iii) dynamic changes in ctDNA during therapy can be easily followed with repeat blood draws. Tissue biopsies allow comprehensive assessment of DNA, RNA, and protein expression in the tumor and its microenvironment as well as functional assays; however, tumor tissue acquisition is costly with a risk of complications. Herein, we review the ways in which ctDNA assessment can be leveraged to understand the dynamic changes of molecular landscape in cancers.
Insights
Liquid biopsies analyze circulating tumor DNA (ctDNA) for cancer mutations, offering a less invasive alternative to tissue biopsies. This method tracks dynamic molecular changes during treatment, improving patient care.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Molecular testing and targeted therapies have advanced cancer treatment.
- Liquid biopsies offer a minimally invasive method for cancer molecular profiling.
- Circulating tumor DNA (ctDNA) analysis provides advantages over traditional tissue biopsies.
Purpose of the Study:
- To review the applications of ctDNA assessment in understanding cancer's dynamic molecular landscape.
- To highlight the benefits of liquid biopsies in oncology.
Main Methods:
- Analysis of circulating tumor DNA (ctDNA) using polymerase chain reaction (PCR) and next-generation sequencing (NGS).
- Comparison of ctDNA analysis with traditional tissue biopsy methods.
- Review of studies leveraging ctDNA for monitoring cancer treatment.
Main Results:
- ctDNA analysis requires only a blood sample, unlike invasive tissue biopsies.
- ctDNA can reflect molecular information from multiple metastatic sites.
- Repeat blood draws allow for dynamic monitoring of ctDNA changes during therapy.
Conclusions:
- Liquid biopsies provide a powerful tool for non-invasive cancer molecular profiling.
- ctDNA assessment enables dynamic monitoring of treatment response and tumor evolution.
- Understanding the dynamic molecular landscape through ctDNA aids in personalized cancer therapy.
