Cancer

Add us on Google

What Is a Multi-Cancer Early Detection (MCED) Test?

A multi-cancer early detection test looks for signals from many cancers in one blood draw. It is a screening add-on, not a diagnosis, and does not replace guideline screening. Here is how Galleri and LucenceINSIGHT each work.

Published

August 27, 2026

Last updated

October 20, 2026

Read time

13 min read

Medically reviewed by

Rhonda Collins, FNP-C

Share

Copy link

Summarize with AI

A multi-cancer early detection (MCED) test is a single blood test that looks for molecular signals associated with several different cancers at once. It is meant to add coverage on top of the cancer screening you already do, such as mammography or colonoscopy, not to replace it. It is a screening tool, not a diagnosis. A result that finds no signal does not mean you are cancer-free, and a result that finds a signal is not a cancer diagnosis: it points to the need for a diagnostic workup ordered by a doctor. Read this way, an MCED test can help surface cancers that have no routine screening test at all. Mito offers two MCED tests that take different approaches: Galleri, from GRAIL, and LucenceINSIGHT, from Lucence.

What does an MCED test actually look for?

Many tumors shed fragments of DNA into the bloodstream. An MCED test sequences that circulating DNA and looks for patterns that suggest cancer is present somewhere in the body at the time of the draw. Most MCED tests also try to predict where a signal comes from, so a clinician has a starting point for follow-up. The two tests Mito offers read different features of that DNA.

Galleri reads methylation patterns on cell-free DNA. Methylation is a chemical tag on DNA, and cancer cells leave a distinctive pattern of it. From one blood draw, Galleri looks for a single cancer signal that GRAIL reports is shared by more than 50 types of cancer, and when it finds one it predicts the tissue or organ the signal most likely comes from, called the Cancer Signal Origin ^[1]. It is one fixed test: you do not choose which cancers it looks for.

LucenceINSIGHT combines three signals from one blood draw: circulating tumor DNA (ctDNA) mutations, cancer-associated viral DNA (for cancers linked to viruses such as Epstein-Barr virus and HPV), and a machine-learning model that predicts the likely tissue or tumor of origin. It comes as panels of set cancers, and one of them can be personalized: you and your doctor decide how wide to cast the net based on your age, family history, and personal risk.

Neither test reads your inherited genes. Both look for cancer that may already be present. They do not measure inherited risk or predict whether you will develop cancer in the future.

Doesn’t my usual bloodwork cover this?

No. Routine health labs and a cancer-signal test answer different questions. Common blood tests such as a lipid panel, a metabolic panel, and a complete blood count show how your heart, metabolism, kidneys, liver, and blood cells are working. They are useful for those questions, and an abnormal value can sometimes prompt a doctor to look for cancer, but none of them is designed to screen for cancer. An MCED test asks a narrower question: is there DNA in the blood that carries a pattern associated with cancer, and if so, where does it most likely come from? One does not substitute for the other, which is why Mito keeps the two side by side in your results rather than treating either as the whole picture.

Why would anyone screen for cancer this way?

Cancer is the second leading cause of death worldwide, according to the World Health Organization ^[2]. The gap MCED tries to close is coverage. Routine, guideline-recommended screening exists for only a handful of cancers (breast, cervical, colorectal, lung in higher-risk smokers, and prostate by shared decision). Analyses derived from GLOBOCAN 2024 ^[3] incidence and mortality data, set against the cancers the U.S. Preventive Services Task Force ^[4] recommends screening for, indicate that over half of U.S. cancer deaths come from cancers with no recommended screening test. Many of those cancers are found only once symptoms appear.

Timing matters because stage at diagnosis drives outcomes. Zeng and colleagues reported in The Lancet in 2021 that 52.8% of cancers were diagnosed at a late stage ^[5]. Five-year survival is far higher when cancer is caught early, as the U.S. National Cancer Institute’s SEER program ^[6] data comparing cancers found while still localized with cancers found after they have spread to distant sites show below.

5-year relative survival by SEER summary stage at diagnosis. Localized means confined to the organ of origin; distant means spread to distant sites. SEER’s third category, regional spread, sits between the two and is not shown. These are not AJCC stage groups. Source: NIH NCI SEER.

One caution about older single-marker blood tests used for screening: they can raise a lot of false alarms. In a large screening trial, Croswell and colleagues found a cumulative false-positive rate of roughly 43% across 14 screening exams using standard methods ^[7]. That is a reason to treat any single positive signal, from any test, as a prompt for careful workup rather than a verdict.

Where does MCED fit alongside guideline screening?

An MCED test is an addition to guideline-recommended screening, never a replacement for it. The screenings with the strongest evidence stay in place: mammography, colorectal screening, cervical screening, low-dose CT lung screening for people who qualify, and prostate screening as a shared decision with your doctor ^[8]. GRAIL states that Galleri should be used in addition to the routine cancer screening a healthcare provider recommends, and Lucence positions LucenceINSIGHT the same way.

No major U.S. screening guideline recommends MCED testing yet, and the evidence on outcomes is still coming in. The U.S. National Cancer Institute is running the Vanguard Study ^[9] to prepare a larger trial of whether these tests can save lives from cancer, and participants keep their standard screening throughout. In England, the NHS-Galleri trial of three yearly Galleri tests found no difference between the tested and control groups in the number of people diagnosed with late-stage (stage III and IV) cancer overall, its main goal. It did report more stage I and II cancers and fewer stage IV cancers in the tested group ^[10]. Whether MCED screening reduces cancer deaths has not been shown.

How often to test is a related question. GRAIL says Galleri can be taken annually ^[11], because a result reflects only the moment of the draw. That is the manufacturer’s position, not a guideline recommendation, so the interval is a decision to make with your doctor.

How well does each test perform?

Performance figures only mean something with their study population attached, and the two tests were studied in very different groups. Do not rank one test above the other by comparing these numbers directly.

Galleri. In GRAIL’s PATHFINDER 2 study, among the first roughly 25,000 participants with one year of follow-up, about 62% of people with a Cancer Signal Detected result were diagnosed with cancer, and 0.4% of participants without cancer received a false-positive result ^[11]. In the NHS-Galleri trial, around a third of people who had cancer received a positive result, and around half of people with a positive result were diagnosed with cancer ^[10]. GRAIL publishes more detail, including sensitivity by cancer type and stage, on its test performance page ^[12].

LucenceINSIGHT. Lucence reports the following from its validation work. In a retrospective analysis of cancer patients across multiple stages, overall sensitivity was 80.9% (233 of 288 patients). Specificity was 99.0% in 313 self-declared healthy donors (310 correctly called negative). Tumor-localization accuracy was 87.7% overall (mean 84.9% across cancer types, range 33.3% to 100%), with a high-confidence prediction possible in about 62.4% of cases. Lucence’s brochure rounds this to roughly 88% accuracy in tumor localization. In a prospective real-world cohort of 264 asymptomatic individuals (2023) and a retrospective cohort of 601 samples (2024), Lucence reported 100% positive predictive value, with all three positive signals in the prospective cohort correlating with a newly diagnosed cancer. These are small cohorts, so read the figures as encouraging early evidence, not settled population performance. A sensitivity measured in people already known to have cancer is not the same as performance in a screening population.

Several limits apply to both tests. Sensitivity varies a lot by cancer type and by stage, and detection is generally easier at later stages than at Stage I. Neither test detects every cancer: cancers that shed little DNA into the blood, such as brain tumors, are hard to detect, and LucenceINSIGHT excludes them. A result that finds no signal does not mean you are cancer-free, and a detected signal needs diagnostic workup.

Who is an MCED test for?

The two tests have different eligibility, so it helps to read them separately.

Galleri. GRAIL recommends Galleri for adults with an elevated risk for cancer, such as those age 50 or older. It is not recommended for people who are pregnant, 21 or younger, or undergoing active cancer treatment ^[11]. No fasting or special preparation is needed. Through Mito, the draw happens at a Quest Diagnostics location, Galleri is not currently available in Arizona, Hawaii, New Jersey, New York, or Rhode Island, and you review GRAIL’s Patient Information Sheet at checkout. GRAIL reports results typically arrive about two weeks after the sample reaches its lab, and sometimes take up to four weeks.

LucenceINSIGHT. Lucence positions LucenceINSIGHT for adults 40 and older, or for younger adults with elevated risk from family history, diet, or lifestyle. It is generally not a fit, subject to your doctor’s judgment, for people who are pregnant, in cancer remission for less than three years, or who have had surgery, an allogeneic bone-marrow transplant, or a blood transfusion within two weeks of the draw. No fasting is required, though a heavy meal within four hours of the draw is best avoided. Through Mito, the blood draw happens at home, and the test is not currently available in Pennsylvania, New York, or Rhode Island. Turnaround is about 25 working days.

Not sure whether MCED fits your situation? The Cancer Risk Profile quiz is a quick way to think through your personal risk before you talk to a clinician.

Broad signal or chosen panel: how wide should the net be?

Galleri is one fixed test that looks for a signal GRAIL reports is shared by more than 50 cancer types. LucenceINSIGHT comes in three panels that trade focus for breadth. Coverage figures below are conservative mortality-share estimates derived from GLOBOCAN 2024, using the brochure’s USPSTF-excluded framing.

LucenceINSIGHT panel coverage of U.S. cancer mortality. Source: GLOBOCAN 2024 (conservative estimates, USPSTF-excluded framing).

There is no single right answer here. Breadth has value because origin prediction is imperfect, many deadly cancers have no screening test, and a wider net looks at more of them. Focus has value because risk, detectability, and the usefulness of acting on a result all differ by cancer. A cancer being in a test’s scope does not mean it is equally detectable. Galleri is the broad, fixed option. LucenceINSIGHT Me is the panel built for personalization, letting you weigh your own risk against what is detectable and what you could actually do about it, and LucenceINSIGHT 12 is the widest Lucence panel. The side-by-side comparison goes further.

Where Mito is different

Mito does not just resell a blood test. Galleri and LucenceINSIGHT are both ordered through Mito, which provides the lab order, and a positive or ambiguous signal lands inside Mito’s care model rather than as a lonely PDF. Your MCED result sits alongside your other Mito results, more than 60 biomarkers spanning heart, metabolic, liver, kidney, and hormone health, so a clinician reads the cancer signal in the context of your whole picture. Mito’s Concierge and 1:1 clinician consults help you decide what the next step should be. Membership is $9 per month or $99 per year, members pay Mito’s cost on tests, and any lab order or draw fee is itemized before you pay. For current prices, see the Galleri and LucenceINSIGHT product pages, or the cost breakdown.

Frequently asked questions

Is an MCED test the same as a cancer diagnosis? No. It is a screening test. A signal means a doctor should order diagnostic testing, such as imaging or a biopsy, to find out whether cancer is actually present.

If my MCED result finds no signal, am I in the clear? No. A negative result lowers the probability of the cancers screened, but it does not rule cancer out, and sensitivity varies by cancer and stage. Keep up with your guideline-recommended screening.

Does an MCED test replace my mammogram or colonoscopy? No. It is designed to complement standard screening, not replace it. Guideline screening remains the foundation.

Does it tell me my inherited cancer risk? No. Galleri and LucenceINSIGHT both look for signals of cancer that may already be present. Neither assesses germline or inherited risk, and neither is a substitute for genetic counseling.

Should I take an MCED test every year? GRAIL says Galleri can be taken annually. That is the manufacturer’s position, and no major screening guideline sets an MCED interval, so decide on timing with your doctor.

Which cancers can it not detect? Neither test detects every cancer. Cancers that shed little DNA into the blood, such as brain tumors, are hard to detect, and LucenceINSIGHT excludes brain tumors and any cancer not on your chosen panel. Being in a test’s scope also does not mean “equally detectable.”

References

1. Blood Test to Detect Cancer Signal Presence. GRAIL (Galleri).
2. Cancer (fact sheet). World Health Organization.
3. Global Cancer Observatory. International Agency for Research on Cancer.
4. U.S. Preventive Services Task Force. U.S. Preventive Services Task Force.
5. Article in The Lancet, 2021. The Lancet.
6. Surveillance, Epidemiology, and End Results Program. National Cancer Institute.
7. Croswell et al. Cumulative Incidence of False-Positive Results in Repeated, Multimodal Cancer Screening. Annals of Family Medicine. 2009.
8. Recommendations: Search Results. U.S. Preventive Services Task Force.
9. Questions and Answers about the Vanguard Study. National Cancer Institute.
10. NHS-Galleri Trial: What the trial found. NHS-Galleri.
11. Frequently Asked Questions (FAQs) for Patients. GRAIL (Galleri).
12. Galleri Test Sensitivity & Specificity. GRAIL (Galleri).

Related reading

• How Ancestry, Genetics, and Aging Shape Your Cancer Risk
• Multi-Cancer Early Detection Test: A Complete Guide
• Building a Personalized Cancer Screening Plan After 40
• Galleri vs. LucenceINSIGHT: MCED Tests Compared
• Multi-Cancer Blood Test Cost and How to Get One
• CA-125 (Cancer Antigen 125)

Medical disclaimer

This article is for informational purposes only. It does not diagnose cancer, provide medical advice, or replace care from a qualified clinician. Multi-cancer early detection tests are prescription-only screening tests, not diagnostic tests, and do not replace guideline-recommended cancer screening. Galleri and LucenceINSIGHT are each laboratory-developed tests performed in a CLIA-certified, CAP-accredited laboratory, and neither has been cleared or approved by the FDA. A result that finds no signal does not mean you are free of cancer, and a result that finds a signal requires diagnostic evaluation ordered by a doctor. Talk with a qualified clinician about whether testing is appropriate for you and how to interpret any result.