Galleri™ blood test for cancer: what is it?

What is the Galleri blood test?

The Galleri blood test is a new early cancer detection test that is currently in clinical trials in the NHS. 

Detecting cancers at an early stage means that they are easier to treat as more treatment options are available.

The NHS screening trial, in partnership with a company called GRAIL, is looking at how effective the Galleri blood test is at detecting cancer in the general population. This exciting clinical trial has become the world’s largest trial for a cancer blood test.

The first group of participants will be around 140,000 people from diverse populations across certain areas of England. Within the trial, participants will have new blood tests completed over two years. This means that the initial results of the Galleri test should be published by 2023. After this, a further one million participants will be invited to take part in a larger study.

Another study (SYMPLIFY) is also underway looking at how effective the Galleri blood test is at diagnosing cancer in people who have non-specific symptoms that might be caused by an undiagnosed cancer.

At the moment, the Galleri multi-cancer test is not available through GenesisCare. We hope that the NHS-Galleri trial will be successful as this will be a game-changer in the way we approach healthcare and cancer diagnosis by ensuring patients get the right treatment as early as possible.

You can find out more here about the tests and scans we use currently at our specialist GenesisCare outpatient centres.

Alternatively please make an enquiry to book an appointment.

How can a blood test detect cancer?

Some blood tests are used to detect specific types of cancer, but there currently isn’t a test that can check for multiple types of cancers at the same time. Galleri is a simple blood test that detects over 50 types of cancer. These include head and neck, bowel, lung and pancreatic cancer. These types of cancers are usually harder to check for at an earlier stage, which means early detection could be life-saving.

The Galleri test works by finding a specific type of DNA fragment called cell-free DNA (cfDNA) in your blood sample:

  • cfDNA is made by cancer cells and can be traced to the source
  • Cell-free means that the DNA (genetic material) is not bound to a cell like they are in your normal cells
  • More of these fragments of DNA are released into the bloodstream when cancer cells are present

It can be difficult to detect cfDNA in your blood as the fragments are present in such a low amount, especially in the early stages of cancer. The Galleri test has shown promise in detecting the location of a cancerous tumour with a high degree of accuracy. This is extremely useful for clinicians to plan how to diagnose and treat cancer for each patient.

If the Galleri test is positive, this will prompt the  doctor to order further tests to confirm if a specific type of cancer is present. The Galleri test is designed to be used alongside current cancer screening processes but will widen our capability in detecting cancers.

Most tests carry the risk of showing a false positive result. This means that the result may show you’re positive for a condition even when you’re not. The NHS trial will measure how effective the Galleri blood test is in keeping false positive results as low as possible.

As of September 2021, early results have shown that the rate of false positive tests from Galleri is 0.5%. This is a promising result as it shows that in a population of 200 people, only 1 person would have a false positive result.

Being cancer aware

While blood tests are important in the cancer screening process, it’s important to be aware of the signs and symptoms as well. Everyone can play a part in detecting cancer early, which means you can too. 

The symptoms and signs of cancer can vary depending on the stage and cancer type. These symptoms can also be non-specific, which means they don’t always point towards a definitive disease.

New symptoms to be aware of are:

  • Weight loss that can’t be explained by diet or exercise
  • Unusual bleeding or bruising
  • Unusual lumps or bumps
  • Unusual changes in bowel habit
  • Fatigue for no obvious reason 

If you’re worried about any signs of cancer, GenesisCare has rapid access diagnostic clinics for a range of services. These include breast cancer, gynaecology, urology, head and neck and haematology. Our clinics are run by specialist consultants who will assess you and ensure you receive the right tests and treatment for your symptoms.

Find out more or book an appointment at one of our diagnostic clinics.