Who will get a Galleri® test

Key points

  • People taking part in the NHS-Galleri trial give a blood sample.

  • Half of the people in the trial get a Galleri® test.

  • Half of the people do not get a test.

  • Only people who get a Galleri test and have a cancer signal detected will get a test result

  • This means that most people will not get a test result.

Flow chart showing that people in the test group of the NHS-Galleri trial get a Galleri test and those in the control group do not get a test. Only people in the test group who have a cancer signal detected get a test result. Half of the people in the NHS-Galleri trial will get a Galleri test and half will not (50:50). Most people in the trial will not get a test result.

Test and control groups

Trials have to be designed in a particular way to understand how well a new test or treatment works. 

The best way to learn this is to compare two groups of people: one group that did get the new test or treatment, and another that did not. These are called the test” and control” groups. 

In the NHS-Galleri trial, half of the people in the trial will be in the test group and half will be in the control group.

People inverted

Test group

People in the test group will have their blood samples tested using the Galleri® test. In this group, a small number of tests are expected to show a cancer signal. Anyone with a cancer signal detected will be contacted about their result. No other results will be shared.

People

Control group

People in the control group will have their blood samples stored. Their samples may be tested in the future. They will not get any results, not even after the trial is finished. A control group is essential in research like this to provide a comparison with the test group.

During and after the trial, the test and control groups will be compared. One of the results that will be looked at is if cancers are found at an earlier stage in the test group than in the control group.

Additional information will be recorded about diagnostic tests and cancer treatments given.

Who will get a Galleri test

When you joined the trial, a computer randomly put you in the test or control group. This was like the computer flipping a coin- you had a 50:50 chance of being in either group.

You will not be told if you are in the test or the control group, not even after the trial has finished

If people know which group they are in, it might alter the way they behave about their health. This could make the research results less clear or reliable. 

Flow chart showing that people in the test group of the trial get a Galleri test, and those in the control group have their blood sample stored. People taking part in the trial were randomly put in the test or the control group, with a 50:50 chance of being in either group. People in the test group will have their blood samples tested using the Galleri test. People in the control group will have their blood samples stored.

Who will get a test result

Most people on the trial will not get a test result. Only people in the test group who have a cancer signal detected will be given their test result.

Flow chart explaining who will get a test result. Most people on the trial will not get a test result. Only people in the test group who have a cancer signal detected will be given their test result. Most people on the trial will not get a test result. Only people in the test group who have a cancer signal detected will be given their test result.

Getting a cancer signal detected result

If you are in the test group, you will be told if your blood sample shows a cancer signal.

A cancer signal does not mean you definitely have cancer. It just means that you might have cancer, and you need to have some further tests to check.

A research nurse from the trial team will contact you about your result and arrange an appointment at an NHS hospital for further tests. Your GP will also be told about your result.

Once the research nurse has arranged for you to be seen in the NHS, the hospital team will contact you to discuss the next steps to investigate the cancer signal result. This could include tests like scans, scopes or further blood tests.

If you have not heard from the NHS within two weeks of talking to the research nurse, please contact the trial team to check on the progress of the NHS appointment that was made for you.

If you have a cancer signal detected and are treated for cancer, you may not need to attend any more trial appointments.

To check if you need to attend an appointment, please contact the trial team to share information about the type of cancer and treatment you have received.

If you do not need to give another blood sample, you will remain an important part of the trial. This is because information about your health will still be shared by the NHS to help with the trial.

About half the people who have a cancer signal detected will be found to have cancer after further tests in the NHS, and the other half will not.

If the Galleri test finds a cancer signal, but no cancer is found after further tests, please continue to attend any cancer screening appointments you are invited to and visit your GP if you experience any symptoms that are new or unusual for you.

No other results will be shared

If you are in the test group and your blood sample shows no cancer signal, you will not be given your result. This is for two reasons:

  1. We are still collecting information on how well the test works in the NHS, so it might give people false reassurance if they were told no cancer signal was detected.

  2. In trials, people often do not know if they are in the test or control group. This is important for getting reliable research results. If you are told your test result, you will know you are part of the test group, which could make the research results less clear or reliable.

Attending your usual cancer screening appointments

It is very important that you keep attending your usual cancer screening appointments when you are invited to do so. You should also make an appointment to talk to your GP if you notice any symptoms that are new or unusual for you.

If you are in the control group, or if no cancer signal is found, you will be sent a thank you letter to confirm that your blood sample has been safely received by the lab. This normally takes around 30 days to arrive after you have had your blood sample taken, but may sometimes take longer. 

You will not know from the letter if your blood sample has been tested or not. It is therefore important that you continue to attend any cancer screening appointments you are invited to and visit your GP if you experience any symptoms that are new or unusual for you.

The control group samples may be tested with the Galleri test in the future to help the trial team understand any differences between what happens to people in the test group and the control group. If you are in the control group, you will not get any test results from the trial, not even after the trial is finished. You will be asked if your samples can be stored and tested after the trial ends to help with other research to improve how well the test works.

Summary

When you joined the trial you were put at random into the test or the control group. There was a 50:50 chance (like flipping a coin) of being in either group.

If you are in the test group you will:

  • Have your blood samples tested using the Galleri test
  • Be told if a cancer signal is detected
  • Not be told any other results

If you are in the control group, you will:

  • Not have your blood samples tested — they will be stored and may be tested in the future
  • Not be told any results

You will not be told if you are in the test or control group, not even after the trial has finished. This is to help make the research results clear and reliable.