Grail’s Galleri Cancer Detection Test: Is It a “Failure”?
- Mary Nell Wegner, EdM, MPH
- 23 hours ago
- 5 min read
A recent front page New York Times article (February 20, 2026) featured a glaring headline, “Grail’s Cancer Detection Test Fails in Major Study.” Within several days, the article had sparked more than ninety responses challenging or refuting the findings that claimed that the Grail company’s Galleri test “did not show a reduction in diagnosis at later stages of disease” based on a large clinical trial conducted in England.
The trial included 142,000 healthy adults aged 50 to 77 and was conducted in partnership with the National Health Service, which tested the participants once a year for three years. In the study, one group of people had their blood tested with the Galleri test; those who tested positive were referred for medical care. The company compared this group to another group that didn’t receive the test. The goal was to see if Galleri could help detect cancer at an earlier stage (Stage 1 or 2). The results showed that the Galleri test, when used annually with a general population, did not lead to a significant decrease in the number of cancers diagnosed at later stages, like Stage 3 (when cancer has spread near its original site) or Stage 4 (when cancer has spread to other parts of the body).
While these results seem disappointing, we asked Cloudberry Health’s Dr. Josiah Child to explain the controversy and assess the utility of this cancer detection test.
Q: What is your analysis of the recent results published in The New York Times about the Galleri test?
The headlines were overly simplistic. They focused on the potential business proposition of the test in relation to insurance and Medicaid coverage as opposed to the clinical utility. The perspectives shared didn’t discuss critical issues such as the importance of the frequency of using the test, who specifically should take it, and how best to complement the test with additional kinds of studies.
Q: Why do you think the headlines were what they were?
Probably to grab people’s attention! The study was set up in a very narrow way, testing only whether Grail’s Galleri test could function as an annual, one-size-fits-all cancer screening tool for the general population. In all likelihood, that was an overly ambitious agenda given the test’s characteristics and how it is actually meant to be used.
It’s a bit like expecting a specialized cardiac test to work as a daily screening tool for everyone. We have EKGs and troponin levels to look for heart attacks, but it wouldn’t be helpful to do an EKG and troponin on every person, every day, “just in case.” You really want to have a reason to do it – some signal that justifies paying extra attention. The Galleri test is similar: testing everyone, all the time, doesn’t make sense clinically or economically.
For a patient with a strong family history of breast cancer, I might recommend doing this test every 6 to 12 months as an added layer of surveillance. For a patient with no personal or family history of cancer, I may not recommend it at all, because the balance of potential benefit, cost and downstream testing looks very different in that context.
Q: Do you see any utility in the Galleri test?
Yes! For deadly cancers (such as anus, bladder, colorectal, esophagus, head and neck, liver/bile duct, lung, lymphoma, ovary, pancreas, plasma cell neoplasm/myeloma and stomach), Grail’s test has reasonable sensitivity even for early stage cancers.
Q: What does “sensitivity” mean in this case?
When doing some kind of testing – in this case, a test that detects cancer “markers” (tiny shards of cancer DNA in the blood) – “sensitivity” tells us how good it is at finding people who actually have a disease. If a test has high sensitivity, it will correctly pick up almost everyone who is sick. A highly sensitive test has few false negatives, meaning a negative test can reliably rule out the presence of disease. For this reason, tests with reasonable sensitivity, such as the Galleri test, serve an important role and are especially useful for screening.
Q: So, what is the Galleri test’s sensitivity?
When I looked at the test results in this study, I found them impressive. Here are the measurements of the sensitivity of Grail’s test for three cancers, based on GRAIL’s multi-cancer early detection validation data:
Pancreatic cancer: Overall 83.7%; 61.9% Stage 1, 60.0% Stage 2, 85.7% Stage 3, 95.9% Stage 4
Liver/bile duct cancer: Overall 93.5%; 100% Stage 1, 70.0% Stage 2, 100% Stage I3, 100% Stage 4
Ovarian cancer: Overall 83.1%; 50.0% Stage 1, 80.0% Stage 2, 87.1% Stage 3, 94.7% Stage 4
These results suggest to me that Grail’s Galleri test absolutely helps to diagnose cancers and support healthcare providers to get individuals the care they need earlier than had they not been tested. To my mind, in targeted settings for people with specific risks, the test is an excellent tool when combined with imaging studies.
Shao S, Allen B, He J, et al. Multi-cancer early detection test sensitivity for cancers with and without existing population-level screening programs. Post-hoc analysis of the Circulating Cell-free Genome Atlas (CCGA) substudy 3. 2021 GRAIL, Inc. Poster presented at Society of General Internal Medicine (SGIM) Annual Meeting; 2021.
GRAIL, Inc. Galleri Test Facts: Test Performance and Cancer Signal Detection by Cancer Type and Stage. Fact sheet, version 05-30-2023. Accessed March 2026.
Klein EA, Richards D, Cohn A, et al. Multi-cancer early detection test sensitivity for cancers with and without existing population-level screening options. Cancer. 2023; 129(13):2153-2165.
Hall DC, Klein EA, Richards D, et al. Leveraging multi-cancer blood tests to improve diagnostic efficiency for patient with nonspecific signs and symptoms. JCO Precis Oncol. 2024; 8:e2300252.
Hamilton W, Crosland P, Walter FM, et al. Multicancer early detection (MCED) test: clinical update for GPs. Br J Gen Pract. 2025; 75(752):e189-e197.
Q: What has been Cloudberry Health’s experience with the test?
Galleri has been a very effective adjunct to other tests, such as scans and scopes – especially with individuals with specific risk factors or who know that something does not feel right and other tests are not picking up disease. It also certainly represents a massive improvement over the previously available blood tests, such as CA125.
Q: Based on this experience, what are your recommendations?
I recommend the Grail’s Galleri test for certain individuals – including those at risk for specific types of cancers and when other blood tests have not picked up an early cancer marker. When combined with imaging studies, especially, it can be an enormous help.
As a provider, my job is to help people understand what is going on when they don’t feel good or when they know something is not right so we try everything possible to support them. The Galleri test is often an important way to get more information quickly and that has value for all of us, especially if it means we can help individuals to get the care they need earlier than had they not been tested.