Liquid biopsy is the analysis of tumor-derived components (CTCs, ctDNA, exosomes) from a blood sample. Minimal-invasive, repeatable and enabling longitudinal monitoring compared with solid biopsy, this approach is shifting the paradigm in cancer research.
Components of Liquid Biopsy
| Component | Source | Information |
|---|---|---|
| CTC | Intact tumor cell | Phenotype, morphology, viable cell |
| ctDNA | DNA released by apoptotic tumor cells | Mutation profile, methylation |
| Exosomes | Vesicles released by tumor cells | Protein, RNA, lipid profile |
| cfDNA | General cell death (all sources) | Total DNA burden |
Advantages
- Non-invasive: sampling with a standard blood draw; no surgical biopsy required
- Longitudinal monitoring: repeated blood draws track tumor dynamics throughout treatment
- Captures tumor heterogeneity: cells from different metastatic sites enter the bloodstream; not limited to a single lesion
- Early detection potential: minimal residual disease (MRD) undetectable by imaging may be found via CTCs
CTC vs ctDNA: Which One, When?
- Prefer CTC: cell phenotype, functional assays on viable cells, immune marker profiles, cell culture
- Prefer ctDNA: mutation detection, minimal residual disease (MRD), tumor burden, resistance mutations
- Both together: comprehensive translational studies typically run them in parallel
Feel free to contact us about our liquid biopsy services.
Rx-only — prescription screening test. Galleri® is not a diagnostic test. A positive result does not mean a cancer diagnosis; a negative result does not rule out cancer. The test does not replace the routine cancer screenings recommended by your physician. Galleri® does not detect all cancers.