A new way to diagnose cancer: Everything about liquid biopsy!

Have you ever heard of the term "liquid biopsy "? Maybe your doctor has told you about it, or you have read about it somewhere. This is a very important, new test method for diagnosing and treating cancer. So, let's talk about it simply and clearly today. There is nothing to be afraid of, it is like your friend explaining something to you.

What is this liquid biopsy? It's very simple!

Simply put, a liquid biopsy is a test that takes a small amount of blood . This can detect whether there are any cancerous tumors. Imagine that as a cancerous tumor grows, small pieces of it can break off and enter your blood. Those pieces are what this liquid biopsy detects.

This test looks for two main things:

• Circulating Tumor Cells (CTCs): These are cancer cells that break away from the tumor and travel through your bloodstream, like little spies.
• Circulating tumor DNA (ctDNA): These are pieces of DNA that break off from cancer cells and enter the blood. As you know, DNA is like a book that contains the genetic code that controls the behavior of our cells. So, these pieces of ctDNA can tell us a lot about cancer.

The presence of these `(CTCs)` or `(ctDNA)` in your blood is evidence that there is a cancerous tumor somewhere in your body. Also, since these pieces also provide `( genetic information)` of the cancer, it will be a great help to your doctor in deciding what treatment is most suitable for you.

Liquid biopsy is a relatively new test. It has the potential to make a big difference in the field of cancer treatment. There are already several uses approved by the US Food and Drug Administration (FDA). Research into this is still ongoing.

What is the difference between a liquid biopsy and the regular biopsy we know?

You've probably heard of a routine biopsy. In it, a doctor takes a small piece of tissue directly from a cancerous tumor and tests it in a lab to see if it contains cancer cells.

However, in a liquid biopsy, a piece of the tumor is not directly taken . Instead, it is used to look for evidence of cancer, which is the cancer cells ``CTCs`` or cancer DNA ``ctDNA`` that we talked about earlier, in the blood.

A routine biopsy is currently considered the best way to determine if cancer is present. It is also called the "gold standard."

In a liquid biopsy, even if you have cancer, there is no 100% guarantee that you will be able to detect signs of it in a single blood sample. However, if cancer is detected in a liquid biopsy, the information it provides about the cancer cells is very valuable, and it can be very helpful for doctors in planning treatment.

In what cases is a liquid biopsy performed?

Your doctor may suggest a liquid biopsy in the following cases:

• If you have metastatic cancer that has spread to other parts of your body and your current treatment is not working as expected. Metastatic cancer is a more aggressive form of cancer that has spread throughout your body. When it spreads like this, it is more likely that pieces of the cancer will break off and enter your bloodstream.

A doctor may order a liquid biopsy to find out things like:

• Determine the prognosis: Liquid biopsies can detect circulating tumor cells (CTCs) for many types of cancer . A low number of cancer cells in the blood indicates a better prognosis. A high number of cancer cells indicates a worse prognosis. So, your doctor can do this test periodically to monitor your condition and adjust your treatment if necessary.
• Make treatment decisions: There are treatments that target only certain cancer cells (targeted therapy). This means that if a cancer cell has a certain error (mutation) in its DNA, it can be given a specific drug designed to attack that error. A liquid biopsy can find these errors. Your doctor can then give you a treatment that is specific to that error.

Also, you can have a liquid biopsy even if a regular biopsy is not possible to diagnose cancer. This is because a regular biopsy is a more invasive procedure than a liquid biopsy. You may not be healthy enough to undergo a biopsy. Or, depending on the location of the tumor, it may be difficult to remove a piece of it without damaging nearby vital organs.

What liquid biopsy tests are FDA approved?

Tests approved by the U.S. Food and Drug Administration (FDA) are those that have been thoroughly researched and proven to be safe and accurate. Several liquid biopsy tests are still in the research stage. There are four main tests that are currently approved by the FDA:

1. Cell Search® Circulating Tumor Cell (CTC) Test: This tests for CTCs. Breast, prostateThis is used to get an idea of ​​the future status of people with cancer that has spread to the colon or rectum. If there are few CTCs in the blood, that's a good sign. If there are many CTCs, that's a little unfavorable.

2. cobas® EGFR Mutation Test v2: This tests for ctDNA. It detects a mutation in the gene called EGFR, which is particularly common in non-small cell lung cancer (NSCLC). This information can help your doctor decide what treatment is best to target that mutation.

3. Guardant360® CDx: This also looks for ctDNA. It is used to detect genetic defects that are common in cancer cells. This helps the doctor choose the most effective treatment.

4. FoundationOne® Liquid CDx: This also looks for ctDNA. This helps to detect genetic defects (mutations) in different types of cancer. This helps the doctor decide what treatment is most appropriate.

How is a liquid biopsy performed? Does it hurt?

A liquid biopsy is a very simple blood test . Just like you would give a blood sample for a regular blood test. A doctor or nurse will take a sample of blood from your arm and send it to a lab for testing.

At the lab, a machine separates your blood into the cell parts (solid part) and the plasma (liquid part). Then, a pathologist, a specialist trained to analyze the fluid and tissue samples, looks for signs of disease in the plasma part, called CTCs or ctDNA.

Does this hurt? No, a liquid biopsy feels just like donating blood. When the needle is inserted into your arm, you may feel a slight tingling sensation, like being bitten by an ant. But that discomfort goes away quickly.

One advantage of a liquid biopsy is that it is a much less invasive and painful procedure than a regular biopsy.

What do the results of this test say?

The test results tell you whether your blood sample contains either `(CTCs)` or `(ctDNA)` (`positive`) or not (`negative`) .

• If the result is ``positive`` , it means that the substances mentioned are present in the blood. Then, these tests can also help find out what type of cancer you have. In particular, tests that look for ``(ctDNA)`` can also identify common genetic defects associated with some types of cancer.

How long does it take to get the results? How accurate is the liquid biopsy?

Test results should usually be available within two to three weeks .

Now let's look at the accuracy of this. Liquid biopsy tests that have been approved by the FDA, what are they designed for, and do exactly that job.

• The doctor can get an idea of ​​the future status of your disease and monitor the condition of your disease through `(CTC)` tests.
• Because ``(ctDNA)`` tests can detect genetic defects in the DNA of cancer cells, they help in making treatment decisions.

However, a liquid biopsy cannot always be relied upon to diagnose cancer with 100% certainty . A standard biopsy is required to confirm the presence of cancer.

Liquid biopsy tests are currently an area of ​​active research and development. The ability to detect and monitor cancer with a simple blood test is a big deal. Research is underway to develop liquid biopsy tests that can detect cancer before it even develops. However, more research is needed to understand the full potential of liquid biopsies. Already, they are helping to diagnose some types of cancer and make treatment decisions in specific cases. In the future, they are likely to have even greater benefits.

Finally, things we need to remember

Okay, so we've talked a lot about liquid biopsy. Here are a few things to keep in mind:

• Liquid biopsy is a new test that looks for cancer markers in the blood .
• This can detect `(CTCs)` (cancer cells) and `(ctDNA)` (cancer DNA).
• There is no major discomfort or pain like a regular biopsy.
• This helps to get an idea of ​​the future status of the cancer and to decide on treatment .
• Some FDA-approved tests already exist.
• However, to definitively confirm cancer, a routine biopsy may be necessary .
• This is a technology that is still developing and could be very useful in the future.

The most important thing is, if you have any questions or concerns about this, definitely talk to your doctor. He or she can explain everything to you in a way that is best for you.

I hope this information is useful to you! Stay healthy!

` Liquid Biopsy, Cancer, Cancer Detection, ctDNA, CTCs, Blood Test, Cancer Treatment