Multi-cancer Detection (MCD) Tests
What You Need to Know About Multi-Cancer Detection (MCD) Tests: The Future of Early Cancer Screening
Imagine taking a single blood test that could look for dozens of different cancers at once—even cancers that don’t have any existing screening tests. This is the promise behind Multi-Cancer Detection (MCD) or Multi-Cancer Early Detection (MCED) tests, one of the most exciting developments in early cancer screening today.
These tests are not yet FDA-approved, but some are already available to consumers. Before deciding whether to get one, it’s important to understand what they can (and cannot) detect, how they work, and why doctors are watching this technology so closely.
What Exactly Are MCD Tests?
MCD tests are lab tests that analyze a sample—usually blood, but sometimes urine or saliva—to look for signals shed by cancer cells. These signals may include fragments of DNA, RNA, proteins, or other molecules that differ from those found in healthy cells.
Unlike traditional screening tests that check for one type of cancer at a time, MCD tests have the potential to identify many types simultaneously, including cancers that do not currently have any recommended screening methods.
Some tests can even suggest where a cancer signal might have started in the body.
Do MCD Tests Diagnose Cancer?
No.
A positive MCD test does not mean you have cancer.
If the test detects something abnormal, follow-up diagnostic testing—like imaging or biopsies—is required to confirm whether cancer is present and identify the type and location.
Since these tests are new, interpreting results can sometimes be challenging, and both false positives and false negatives are possible.
Why Are MCD Tests Such a Big Deal?
Early detection saves lives.
Cancers found before symptoms appear are often easier to treat. But here’s the problem: only a handful of cancers have proven screening tests today—breast, cervical, colorectal, prostate, and lung. Nearly half of all cancers diagnosed each year occur in types without any recommended screening methods, meaning many are discovered far too late.
MCD testing could change that.
By scanning the blood for signals from dozens of cancers at once, these tests may allow doctors to catch more cancers earlier—even the hard-to-find ones.
Are Any MCD Tests FDA-Approved?
Not yet.
However, some tests—like Galleri and Cancerguard—are offered as lab-developed tests (LDTs) under CLIA regulations. Doctors can order them, but the FDA has not reviewed or approved them.
Companies are currently gathering data needed to pursue FDA approval. Until then, MCD tests are considered emerging tools, and experts caution that more research is required before they can be recommended for routine screening in people without symptoms.
One important note:
Even if approved, MCD tests will not replace standard screenings like mammograms, Pap/HPV tests, colonoscopy, PSA tests, or lung CT scans. Instead, they would be used alongside existing tools.
Will My Insurance Cover an MCD Test?
For now, most insurance plans—including Medicare—do not cover these tests.
Prices vary, but most cost several hundred dollars out of pocket. Additional follow-up testing after a positive result can also be expensive.
Coverage may change over time as more research becomes available and legislation evolves.
The Big Questions Researchers Are Still Working To Answer
Even though the technology is promising, scientists still need answers to key questions:
1. How accurate are these tests?
Some cancers are easier to detect than others, and accuracy varies.
2. Who benefits the most?
Should these tests be used for everyone or only for people at higher risk due to age, genetics, lifestyle, or exposures?
3. How early can they find cancer?
Can they spot cancer early enough to improve treatment outcomes?
4. Do these tests actually save lives?
This is one of the most important unknowns. Researchers need to determine whether early detection via MCD tests reduces cancer deaths.
5. What’s the ideal follow-up after a positive test?
Doctors are still determining the best steps when an MCD test detects a cancer signal.
6. How often should people take these tests?
The optimal frequency is not yet known.
Understanding False Positives and False Negatives
Like any test, MCD testing isn’t perfect.
False Positives
More than half of people with a positive MCD result are ultimately found not to have cancer.
This can cause anxiety and lead to additional—and sometimes invasive—testing.
False Negatives
A negative result doesn’t guarantee you are cancer-free.
You should still follow recommended screening guidelines and pay attention to new or unusual symptoms.
The Importance of Shared Decision-Making
Because there are still so many unknowns, doctors recommend using MCD tests only after a thoughtful discussion—known as shared decision-making.
This means talking with your healthcare provider about:
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potential benefits
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possible limitations
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cost and insurance coverage
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follow-up steps after abnormal results
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your personal preferences and health goals
If you’re not willing or able to pursue additional testing after a positive result, an MCD test may not be the right choice.
Questions to Ask Your Doctor Before Getting an MCD Test
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What does the test measure?
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Which tests are available?
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Am I a good candidate for MCD testing?
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What does it cost, and will my insurance cover any part of it?
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What are the benefits and risks?
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How often would I need the test?
What the American Cancer Society Is Doing
The American Cancer Society (ACS) is deeply involved in moving MCD testing forward through both research and advocacy.
Research
ACS funds studies to evaluate MCD accuracy and effectiveness and collaborates with test developers to better understand how these tests perform in diverse populations.
Advocacy
ACS CAN (the advocacy arm of ACS) supports legislation designed to improve access to MCD tests once FDA-approved.
One key initiative is the Nancy Gardner Sewell Medicare Multi-Cancer Early Detection Screening Coverage Act, which would help pave the way for Medicare coverage.
The Bottom Line
MCD tests represent one of the most promising advancements in cancer screening. They have the potential to transform early detection by identifying dozens of cancers from a single blood draw.
But while the technology is exciting, there’s still a lot we need to learn.
For now, the best approach is to stay informed, continue routine cancer screenings, and talk with your doctor about whether MCD testing is appropriate for you.
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