What is the Galleri blood test for cancer?

Research in England and Wales is looking into a new blood test that could detect a range of cancers. Research looking at this test has so far been promising, but it needs to be tested further in larger trials. The test is called the Galleri blood test and it's made by a company called GRAIL Bio UK Ltd. It is not available in the UK outside of a clinical trial.

The NHS Galleri screening trial will look at the test in people who do not have cancer. This trial is now open in parts of England.

The SYMPLIFY study is looking at the Galleri test in people with possible cancer symptoms. This is now recruiting in parts of England and Wales. 

People will be invited to take part in this research. You cannot volunteer to take part. 

What does the Galleri blood test look for?

The test looks for abnormal DNA Open a glossary item in the blood. The cells in our body release DNA that circulate in the blood. There are differences in the DNA of healthy cells and cancerous cells. The test is designed to pick up these differences. Your blood is tested for signals that might mean you have cancer.

The aim is to pick up cancers at an early stage. The earlier a cancer is diagnosed, the greater the chance of a person being treated successfully.

The NHS Galleri screening trial

This trial is the result of a partnership between NHS England and a company called GRAIL. The trial team will use NHS records to search for people aged 50 to 77 who have:

  • not been diagnosed with cancer in the last 3 years, or
  • not been treated for cancer in the last 3 years 

People in some parts of England will then be invited by letter to join. The trial team hope to recruit 140,000 people. 

If you take part in this trial, you have 3 blood tests over the course of 2 years. This is a randomised trial. This means that those taking part are put into one of two groups by a computer.

  • half the people have their samples tested using the Galleri test - this is the test group
  • the other half don’t have the Galleri test and their blood samples will be stored and may be tested in the future - this is the control group

You cannot choose which group you are in and you won't be told if you are in the test or control group. 

If you are in the test group and your result shows a cancer signal, this does not mean that you definitely have cancer. It means that you might have cancer. The trial team will explain your results. And refer you to a specialist doctor at your local hospital. You might have further tests. 

What are the benefits and risks of taking part?
The trial results may show that the Galleri test is able to pick up cancer early, when it is easier to treat. You could be helping others by taking part because more cancers could be treated successfully. 

The Galleri test is not perfect and can give a wrong result. This could cause you some anxiety. You may have tests that are unnecessary if you are found not to have cancer. 

When you go to have your blood sample a member of the trial team will explain the possible benefits and risks of taking part.

The SYMPLIFY study

This study is looking at the Galleri test in people with possible cancer symptoms. Those invited to take part have been referred urgently to have tests or to see a hospital specialist. 

Everyone in the study has tests to check for cancer in the usual way. Those who agree to take part in SYMPLIFY also give a sample of blood which is tested with the Galleri test. 

The study team will check your health records at a later date. They will collect information about other tests you have, test results and other appointments.

Hospitals in England and Wales are involved in this research. You may be invited to take part by letter if you live near to one of these hospitals and you have had an urgent referral for suspected cancer.

Has it already been tested?

An earlier version of the Galleri blood test has been looked at in America. These trial results showed that the test was able to pick up over 50 types of cancer. This included those types of cancer that are difficult to diagnose early, such as pancreatic cancer and oesophageal cancer. 

This is very early research in a small number of studies. The blood test now needs to be tested in a larger number of people with both common and less common cancers. And the people taking part also need to be followed for longer.

We have more information about the Galleri blood test and the research so far in our press story.

I have symptoms of cancer, what should I do?

You should contact your doctor if you notice a change that isn't normal for you, or if you have any possible signs and symptoms of cancer.

Even if you take part in this research, it is still important that you contact your doctor if you notice any change that isn’t normal for you. Or if you notice a change continues or worsens even after you’ve sought help for it.

Your GP can refer you to a specialist or to have tests if they are concerned that you might have possible symptoms of cancer. 

Cancer screening

It’s very important that you consider cancer screening when you are invited, whether you are part of this research or not. This trial does not replace cancer screening. There are 3 national screening programmes in the UK:

Remember cancer screening is for people with no symptoms at all. If you have symptoms, don’t wait for a screening invitation. Contact your doctor as soon as possible.

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