Liquid biopsy: information from the blood
A liquid biopsy tries to get information about a disease from a blood sample instead of tissue or bone marrow, for example from fragments of DNA circulating freely in the blood.

01Short answer
02Simple explanation
A blood sample.
Cell-free DNA.
Fewer marrow tests: the aim.
Still in research.
03Scientific explanation
NCI: a liquid biopsy is a test that looks for cancer cells or pieces of their DNA in a blood sample.
NCI: new treatments are tested step by step, from the laboratory to clinical trials; only those proven safe and beneficial become standard care.
04What happens in the body?
ctDNA
DNA released into the blood from cancer cells.

Bone marrow
Still the main sample in leukaemia.

How to read the news
Research news brings hope, but not every advance suits everyone. Look at who it was tested in, at what phase and in how many people.
Talk to your doctor
Show your doctor what you have read; they will explain how it relates to your diagnosis and treatment. Do not change your treatment on your own.
05From research news to a conversation: four steps
Read, check, ask, decide together.







06Key points at a glance
| Topic | In brief |
|---|---|
ctDNA | DNA released into the blood from cancer cells. |
Bone marrow | Still the main sample in leukaemia. |
How to read the news | Research news brings hope, but not every advance suits everyone. Look at who it was tested in, at what phase and in how many people. |
Talk to your doctor | Show your doctor what you have read; they will explain how it relates to your diagnosis and treatment. Do not change your treatment on your own. |
07Key terms
- Liquid biopsy
- A test using blood or another fluid.
- Cell-free DNA
- DNA fragments circulating freely in the blood.
- Clinical trial
- Testing a new treatment with volunteers.
- Evidence
- A result confirmed by reliable research.
08Key points
- Give blood.
- Measure.
- Compare.
- Check the source.
- Talk to your doctor.
09Frequently asked questions
Is a bone marrow test no longer needed?
It is still needed; blood tests do not fully replace it.
Can I have this test?
Some are available in trials; ask your doctor.
Is this advance right for me?
Only your treating doctor can say, based on your diagnosis, stage and condition.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
Is a bone marrow test no longer needed?
Can I have this test?
Is this advance right for me?
12Sources
- National Cancer Institute. NCI Dictionary of Cancer Terms: liquid biopsy
- National Cancer Institute. What Are Clinical Trials?
- National Cancer Institute. Phases of Clinical Trials
- National Cancer Institute. Using Trusted Resources
- National Cancer Institute. NCI Dictionary of Cancer Terms: drug resistance
- National Cancer Institute. NCI Dictionary of Cancer Terms: menin inhibitor
- National Cancer Institute. NCI Dictionary of Cancer Terms: antibody-drug conjugate
- National Cancer Institute. NCI Dictionary of Cancer Terms: bispecific antibody
- National Cancer Institute. NCI Dictionary of Cancer Terms: T-cell receptor
- National Cancer Institute. NCI Dictionary of Cancer Terms: umbilical cord blood transplantation
ctDNA
Bone marrow
How to read the news
Talk to your doctor