Cancerguard vs. Galleri: How the Two Multi-Cancer Blood Tests Compare

A new kind of cancer screening has arrived in the US: multi-cancer early detection (MCED) blood tests, which look for signs of many cancers at once, including ones with no routine screening today. The two best-known are Galleri, from Grail, and Cancerguard, from Exact Sciences, the company behind Cologuard. Searches comparing them have surged since an FDA advisory panel endorsed Galleri on September 23, 2026. Here is how they stack up.

The short answer

Galleri has the larger evidence base, fewer false alarms, predicts where in the body a cancer is likely to be, and is closest to FDA approval. Cancerguard is cheaper, measures more than one type of biomarker, and reported higher sensitivity in its development studies, but with more false positives and no prediction of cancer location. Neither replaces standard screening, and they have never been compared head to head.

What each test measures

Tumors shed traces into the bloodstream. Galleri reads DNA methylation — chemical tags on fragments of DNA that differ between cancerous and healthy tissue — and uses machine learning to decide whether a cancer signal is present and which organ it most likely came from.

Cancerguard combines two classes of biomarker: DNA methylation and proteins associated with cancer. The idea is that different cancers shed different signals, so looking at more than one type may catch cancers that a single approach would miss. Exact Sciences says it can pick up signals from more than 50 cancer types and subtypes, including lung, pancreatic, liver, esophageal, ovarian and stomach cancers.

How accurate are they?

This is the hardest comparison, because the headline numbers come from different kinds of studies.

Galleri’s key figures come from PATHFINDER 2, a prospective study of people tested in real-world screening. Specificity was about 99.6%, meaning well under 1% of people without cancer got a false alarm. The predicted origin was right about 94% of the time, and roughly half of detected cancers were stage I or II. But it caught only about four in ten of all cancers diagnosed within a year.

Cancerguard’s figures come from test-development studies involving more than 20,000 participants. It reported 64% sensitivity overall (excluding breast and prostate cancer), 68% across six of the deadliest cancers, and detected more than a third of stage I or II cancers. Its specificity was 97.4%, meaning about 2.6% of people without cancer would get a false positive — several times Galleri’s rate.

Why not simply conclude Cancerguard catches more cancers? Development studies often compare blood from people already known to have cancer with blood from people who don’t, and that design usually produces higher sensitivity than testing a general population where cancers are rare and early. Until both tests are measured the same way, the sensitivity figures can’t be fairly compared.

What happens after a positive result

This is a real practical difference. A positive Galleri result comes with a predicted cancer signal origin, so doctors can start with targeted tests for that organ. Cancerguard does not predict location; a positive result instead leads to an imaging-guided pathway, typically whole-body scanning, to look for the source. Either way, a positive result is not a diagnosis: it triggers follow-up tests, and sometimes a biopsy, and some people with positive results turn out not to have cancer.

Who they are for

Galleri is being reviewed by the FDA for adults 50 and older. Cancerguard is recommended for people aged 50 to 84 who have not had a cancer diagnosis in the past three years. Both require a prescription, which can come from a regular doctor or, in many cases, a telehealth service, and both companies stress that the tests do not replace mammograms, colonoscopies, cervical screening or lung scans for those who qualify.

Regulatory status

Neither test is FDA-approved today. Both are sold as laboratory-developed tests. Galleri is furthest along: Grail filed for approval in January 2026, and an FDA advisory panel voted 7–2 that its benefits outweigh its risks, though it split 6–4 on effectiveness after the large NHS-Galleri trial missed its main goal. Exact Sciences is enrolling up to 25,000 people in a real-world registry under an FDA-reviewed investigational exemption to support a future submission.

What they cost

At the time of writing, Cancerguard lists at $689 and Galleri at roughly $950. Both are mostly paid out of pocket, and both can generally be paid for with HSA or FSA funds. A federal law signed in February 2026 creates a path for Medicare to cover FDA-approved MCED tests starting in 2028, phased in by age and limited to about one test a year — which is one reason FDA approval matters so much to both companies.

How to think about the choice

For someone weighing one of these tests, the useful questions are: How much would a false alarm, and the scans that follow, worry me? Do I value a predicted cancer location? Can I afford it, possibly every year? And am I up to date on the screening tests that are already proven? A test that finds some cancers early is valuable; a test that leads someone to skip a colonoscopy is not. It is worth discussing with a doctor or pharmacist before ordering. This explainer is general information, not medical advice.