The Galleri test

What is the Galleri® test

Galleri is a multi-cancer early detection (MCED) test developed by GRAIL. Rather than looking for one cancer at a time, it analyses methylation patterns in cell-free DNA (cfDNA) in the bloodstream to identify a signal associated with cancer.

When a cancer signal is detected, the test correctly predicts the cancer signal origin in 93% of cases.

Its particular value is that most of these cancers have no recommended screening program in the UK at all. Galleri is designed to complement, not replace, established programmes such as breast, cervical and bowel screening.

The Galleri® Test is offered by LoveMyLife in partnership with Preologi, who are the first provider in the UK to offer the Galleri® Test.

What the studies show

Galleri is supported by a large evidence base for a screening test in the intended-use population: the PATHFINDER and PATHFINDER 2 studies (around 42,500 participants) and the NHS-Galleri trial, the world’s largest MCED study, with more than 142,000 participants.

• 99.6% specificity, fewer than 1 in 200 people without cancer, will receive a false positive result

• 40.4% overall sensitivity across all cancers (73.7% for the 12 deadliest cancers).

• ~93% accuracy in predicting the cancer’s tissue of origin.

• 61.6% positive predictive value, around 6 in 10 positive results are confirmed as cancer.

More aggressive cancers tend to release more cell-free DNA into the bloodstream at early stages, making them more likely to be detected by Galleri.

Detection sensitivity by cancer stage

• Stage I: 16.8%

• Stage II: 40.4%

• Stage III: 77.0%

• Stage IV: 90.1%

Sensitivity varies considerably by cancer type; it is highest for the higher-mortality cancers that shed more DNA earlier. No MCED test has yet published evidence that screening reduces cancer mortality.

What it cannot do

We would rather you knew this before you booked than after.

• A ‘No Signal Detected’ result does not mean you are cancer-free. Galleri looks for a signal associated with cancer in the bloodstream, but no test can detect every cancer. A ‘No Signal Detected’ result means that Galleri did not detect a cancer signal at the time of testing; it does not rule out cancer or guarantee that cancer is not present.

• It does not replace NHS screening. If you are due a mammogram, a bowel-screening kit, a smear or a lung scan, have those. Galleri sits alongside them, it does not stand in for them.

• It does not investigate symptoms. If something is worrying you, a doctor's appointment is the right front door, not this test.

• The impact of the test on cancer survival is not currently known. It has not yet been established whether using Galleri to detect cancer improves survival.

Important information: Intended use & limitations of the Galleri® Test

• Intended for adults with an elevated risk of cancer, such as those aged 50 or older.

• Does not detect all cancers; must be used in addition to, not instead of, routine screening.

• A positive result requires diagnostic confirmation through further clinical investigation.

• A negative result does not rule out cancer or replace ongoing screening participation.

• Not recommended for those pregnant, aged 21 or under, or in active cancer treatment.

• No MCED test, including Galleri, has yet published evidence that screening reduces mortality; this is the subject of ongoing trials.

Source: GRAIL, Galleri Important Safety Information & Intended Use.

So this is an early-detection test with real strengths and real limits. For some people it is a sensible extra layer. For others it will add worry and cost without adding much. The consultation exists to work out which you are.

Who it suits

Galleri tends to make most sense for adults from around 50, and for younger adults with a family history or other reason to be watchful, who are already keeping up with NHS screening and want to look wider than the programmes cover. It is a considered choice, not a routine one.

It is a poor fit if you have symptoms you have not had checked, if you are looking for reassurance that would be better answered by keeping up with standard screening, or if a positive result you could not act on would cause you more harm than the test could offer. We will talk all of this through before you spend anything.

Price

£1,300 all in if you go ahead: the consultation, the test and your doctor's review of the result.

The consultation is £120. Go ahead with the test and that £120 is part of the £1,300, with nothing added for the consultation. If the test is not right for you, or you decide not to proceed, you pay only the £120 for the consultation.

For an in-person consultation you pay afterwards. For a video or phone consultation the £120 is taken when you book.