Grail is a blood test that is marketed to detect many kinds of cancer. This is nicknamed a “liquid biopsy” because a blood test is much easier on a patient that surgically removing a piece of tissue for a biopsy.
I sent away for a Grail Galleri(R) test before my open-heart surgery in 2024. As a double breast cancer survivor, I figured that it would be reasonable to check whether I had a lurking cancer before investing the huge amount of suffering in the heart surgery.
But just before I opened the test, I read a Lancet article that said the test had high levels of both false positives and false negatives, making it essentially useless. I returned the test and got my money back.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)02830-1/fulltext
A new study is equally disappointing.
https://www.nytimes.com/2026/02/20/health/cancer-detection-test-grail.html
Grail’s Cancer Detection Test Fails in Major Study
https://www.nytimes.com/2026/02/20/health/cancer-detection-test-grail.html
A closely watched clinical trial in Britain that screened blood for early detection of cancer did not show a reduction in diagnoses at later stages of the disease.
By Rebecca Robbins and Gina Kolata, The New York Times, Feb. 20, 2026
A promising blood test aimed at early detection of cancer failed to reduce late-stage cancer diagnoses in a major clinical trial, the test’s maker, Grail, announced on Thursday…
Demand for tests to detect cancer and other diseases has grown in recent years, reflected by a surge of interest among companies and consumers. Exact Sciences offers a test, Cancerguard, that is similar to Galleri. And medical centers are promoting whole body scans with M.R.I. or CT imaging to look for tumors…
The study enrolled 142,000 healthy adults ages 50 to 77 in Britain and followed them for three years. People had their blood drawn three times, each spaced about a year apart. One group of participants’ blood samples were run through the Galleri test, and those people were referred for medical care if they tested positive.
The company compared the group that underwent Galleri screening with another group that didn’t get the test. The hope was that with Galleri, people would receive cancer diagnoses earlier, in Stages 1 or 2.
But recipients of the Galleri test did not show a significant reduction in the total number of cancers diagnosed at Stage 3, when the disease would have grown or spread near its original site, or Stage 4, when the cancer would have spread to other parts of the body, according to the company…
Grail’s stock was down 50 percent on Friday. Nearly all of the company’s revenue comes from sales of the Galleri test. [end quote]
This is disappointing but not unexpected based on the earlier Lancet report.
Also, meeting the primary endpoint (a significant increase in early cancers with a concommitant reduction in later-stage cancers) would not necessarily result in the true benefit: a reduction in mortality. That’s because cancers can seed themselves , go dormant and hide from the immune system for years, only to wake up and roar into lethal metastatic cancer later.
There’s a lot of work going on in this field. I hope they succeed in time.
Wendy