The next era of cancer prevention is not a trend 

The next era of cancer prevention is not a trend 

Exploring the promise of Multi-Cancer Early Detection (MCED) technology to identify cancers earlier, including types with no routine screening 

By Shaun Francis, CEO of Medcan 

Last year, we surveyed Medcan clients to learn which health topics matter most to them. The clear number one response was cancer prevention and early detection. 

That interest reflects a reality many Canadians know all too well: cancer remains the leading cause of death in our country, accounting for approximately 1 in 4 lives each year. 

But now, a new form of early cancer prevention screening technology is back in the headlines, continuing to generate attention among researchers, physicians, and health providers around the world as it recently passed an important preliminary step towards FDA approval. Known as Multi-Cancer Early Detection (MCED) pronounced “em-said” screening (also known as Multi-Cancer Detection MCD) it uses a blood sample to look for a cancer signal, which can include cancers we do routines screen for, as well as many cancers that currently have no routine or recommended screening. 

The concept is transformative. One blood test that screens for multiple cancers at a time before symptoms develop. Certain MCED tests also predict where in the body a cancer is – a feature that helps physicians direct quick and efficient diagnostic workup. 

Through our journey becoming the first commercial provider of one MCED in Canada – the Galleri test by GRAIL – we’ve experienced clients going quickly from result to a confirmed cancer diagnosis. Encouragingly, we saw in certain cases, cancers such as pancreatic and colon were found at earlier stages – when outcomes are much more promising. 

So, it’s no surprise that momentum behind MCED testing continues to build. It’s why you may have recognized the acronym MCED before digging into this piece. You may have also read about this technology recently in major media outlets like the Globe & Mail, USA Today, or Wall Street Journal because the FDA review process has reached a significant milestone by convening an advisory committee to consider the Galleri test for premarket approval. 

In September 2026, the FDA's Molecular and Clinical Genetics Devices Advisory Committee voted unanimously (10-0) that the Galleri test is safe, voted 6-4 the test is effective, and voted 7-2 (with one abstention) that the benefits outweigh the risks for adults aged 50+. This makes Galleri the first MCED test to receive this type of endorsement from an FDA advisory committee. While the FDA is not required to follow the panel's recommendation, advisory committee votes are highly influential in the approval process. The step was widely viewed as a positive development in Galleri's regulatory review process. 

The significance of these developments has also been reflected in the market. Ahead of the advisory committee meeting, GRAIL's stock rose more than 30% following the release of FDA briefing documents, a signal of investor confidence in GRAIL’s Galleri test. Recent gains have been driven primarily by positive regulatory developments and the growing belief that multi-cancer early detection could become an important part of future cancer screening. 

Beyond that, a growing amount of clinical data continues to bring more attention to the potential role of MCEDs in the future of cancer detection.  

At Medcan, advances in cancer prevention and early detection are always on our radar. Therefore, we have been monitoring the many MCED research studies which back their products several years before we brought commercial MCED testing to Canada. We continually monitor emerging screening technologies, assess the evidence behind them, and evaluate whether they have the potential to improve health outcomes. In some cases, that means recognizing the promise and positive impacts of technology before it becomes widely adopted.  

We've done that before. Years ago, Medcan became the first provider in Canada to offer Non-Invasive Prenatal Testing (NIPT), recognizing its clinical value well before it became broadly available and publicly funded for eligible patients across Canada. 

We took a similar approach when we first encountered MCED technology. We reviewed the evidence. We evaluated the clinical trial data. We consulted extensively with physicians and experts. And after rigorous review we chose to partner with GRAIL to become the first provider the Galleri® test and bring it to Canadians. 

Today, we are more than a year into our experience with an MCED, and we’ve performed more than 5,000 tests that have resulted in numerous Cancer Signal Detected findings. It has provided us with a compelling firsthand glimpse into this major breakthrough in cancer screening and early prevention. 

What is Multi-Cancer Early Detection (MCED) screening? 

Multi-Cancer Early Detection (MCED) screening is a new type of cancer technology and test that aims to detect a signal from multiple cancer types through a single blood test, often before symptoms develop.  

Rather than looking for one specific cancer, MCED tests are designed to screen for numerous cancer types at once. These include many of the deadliest cancers, such as pancreatic, esophageal, ovarian, and liver that have no existing or routine screening options. 

Traditional screening tests, while still very important, are typically designed to detect one cancer at a time. In Canada, we have the following:  

• Mammography for breast cancer (Find on more of our recommendations here, including specific criteria for dense breasts). 
• Colonoscopy or FIT for colorectal cancer (Read why we recommend colonoscopy as the gold standard here.) 
• Human papillomavirus (HPV) testing for cervical cancer 
• Prostate exams and PSA for prostate cancer 
• Low-dose CT for lung cancer in eligible individuals 

But as Medcan physician Dr. Steven Poirier, who has been involved with Medcan’s partnership with GRAIL since the beginning, points out, "Outside of the current screening options for those five cancers, we have had no other way to screen for most other cancer types.”   

Today, approximately 70% of cancer-related deaths occur from cancers for which there is currently no recommended routine screening test. 

How does an MCED test work? 

An MCED test is commonly referred to as a ‘liquid biopsy’ that looks for clues of cancer in the body. Just like other cells in our body, when cancer cells die, (all cells grow and die in regular cycles) they shed tiny fragments of genetic material and other biological markers into the bloodstream.  

Depending on the technology, MCEDs analyze blood samples to look for these cancer-associated signals, which may include: 

• Cell-free DNA (cfDNA) 
• RNA 
• Proteins or other biomarkers 

Advanced genetic testing protocols and artificial intelligence algorithms are then used to identify patterns that may indicate cancer and, in some cases, predict where the cancer originates.  

Interestingly, the origin of this technology is tied to an unexpected discovery in prenatal testing. 

In 2015, researchers working with Illumina's Non-Invasive Prenatal Testing (NIPT) technology noticed that some pregnant women were showing unusual genetic signals in their blood that did not come from the fetus. Further investigation revealed that, in some cases, these abnormal DNA fragments were coming from undiagnosed cancers in the mother.  

That discovery sparked the idea that if cancer-related DNA could be detected in the blood of seemingly healthy people, it might be possible to create a blood test capable of finding cancer before symptoms appear. To pursue that idea, Illumina spun out a new company called GRAIL in 2016. The company's name was chosen because its founders viewed a simple blood test for early cancer detection as the "holy grail" of cancer screening. 

An exploration of what we’ve discovered working with the most extensively studied MCED 

The Galleri test is an MCED, developed by GRAIL is the most extensively researched MCED test, with data from multiple randomized studies involving hundreds of thousands of participants. 

Last year, we became the first official provider to bring this test to Canada, and since then, we’ve been sharing our progress. Read our 6-month review here. 

Here’s how it works:  

The Galleri test looks for tiny fragments of DNA (cell-free DNA, cfDNA) that cancer cells can shed into the bloodstream and analyzes specific chemical tags on that DNA called methylation patterns. 

As Dr. Poirier explains, “Every cell in your body contains DNA, but not every gene is turned on or off in the same way. One of the ways the body controls this is through a process called DNA methylation, which acts like a set of chemical switches attached to the DNA.” 

When cancer develops, these methylation patterns often change in recognizable ways. So rather than looking for cancer itself, the Galleri test: 

• Finds small pieces of DNA circulating in the blood (called cell-free DNA). 
• Analyzes the methylation patterns on that DNA. 
• Uses AI and machine learning to determine whether those patterns look more like cancer DNA or healthy DNA. 
• If a Cancer Signal Detected comes back, the Galleri test also predicts where in the body the cancer may have originated.  

“The predicted site of origin is an important key differentiator of the Galleri test. Not all MCEDs provide this information,” explains Dr. Poirier.  

Knowing where to look in the body helps medical professionals move to the next phase of diagnosis and treatment. For example, if the test result indicates that there is a cancer signal and the potential origin is the liver, the physician can order testing that specifically looks at that organ, rather than searching across the whole body. 

Does it hurt?  

No. An MCED requires a blood draw, making it simple and non-invasive. 

While most MCEDs use one tube of blood taken during one visit, some tests may require multiple vials and different laboratory processing, but they are still considered a single blood-draw test.

In our experience with the Galleri test, it requires one blood draw. Many clients do it alongside their Annual Health Assessment, so they can have the blood drawn during the same appointment. It can also be done as a standalone appointment at most of our Medcan locations. Earlier this year, we also expanded access across Ontario and into British Columbia, where you can now complete the blood draw through an in-home visit or at a local blood collection centre. 

At Medcan, here is an overview of the typical process: 

• A single non-fasting blood draw is collected. 
• The test is sent to the GRAIL lab in North Carolina for analysis. 
• Medcan will review your results with you via virtual appointment when they are available, within four weeks of the date of your blood draw. 
•  If a Cancer Signal Detected result comes back, the Galleri test predicts where the signal originated, supporting next-step diagnostic investigations. Medcan will facilitate follow-up testing and coordinate ongoing care. 
• If no cancer signal is detected, you may continue with their regular screening and proactive health plan. The Galleri test should be used annually in addition to healthcare provider recommended screening tests. It does not replace other cancer screening protocols. 

How effective are MCEDs? 

Many MCED technologies have shown promising results in laboratory studies or early clinical trials. However, Galleri has generated some of the largest prospective studies in asymptomatic adults, including PATHFINDER and the NHS-Galleri trial, and as a result, much of the published evidence comes from Galleri research. 

As the most extensively studied MCED test currently available, Galleri test studies involve more than 380,000 people worldwide, and research is ongoing.  

Large-scale clinical trials include the CCGA (over 15,000 participants), PATHFINDER (~6,600 participants), and the largest interventional study of an MCED test in the United States to date, PATHFINDER 2 with 35,878 participants (including participants from UHN in Toronto). Also, the first randomized control study of an MCED through the NHS-Galleri trial in the UK with over 140,000 participants. 

According to Medcan’s Head of Clinical Innovation, Allison Hazell, “This is why we chose to partner with GRAIL. Our clinical innovations team undergoes a rigorous review process before we bring any advanced health technology into the Medcan ecosystem or to Canada.” 

At Medcan, we evaluate a clinical tool based on safety, effectiveness, and to ensure it has no psychological impacts. By the time we introduced the Galleri test to Canada, it had already been made commercially available in the United States for 4 years. 

Here is what current research shows: 

• When the Galleri test is added to recommended cancer screening, approximately three times as many cancers were detected compared with guideline-recommended screening alone in a large clinical study.  
• The test is designed to identify signals associated with more than 50 types of cancer, many of which currently have no recommended routine screening test. The test’s sensitivity (detection rate) is particularly high for detecting liver / bile duct (93.5%), pancreatic (83.7%), and ovarian (83.1%) cancers.   
• When a cancer signal is detected, Galleri can predict the likely tissue or organ of origin with more than 90% accuracy. 
• Galleri demonstrated 76.3% sensitivity across all stages for a group of 12 high-mortality cancers responsible for approximately two-thirds of cancer deaths in the U.S.  
• The test has a specificity of 99.6%, meaning false positives - those diagnosed but who are later found to not have cancer - are uncommon. 
• Studies have also found that most participants report little to no significant psychological distress during the MCED test process. The vast majority - 97% - report being satisfied, very satisfied, or extremely satisfied with their MCED experience 

While no screening test is perfect, and MCED technology continues to evolve, the results to date on the Galleri test have been encouraging and suggest it could become an important complement to existing cancer screening tools. 

While studies have demonstrated the ability of MCED testing to identify cancers earlier, researchers are still evaluating the ultimate question: whether widespread use of MCED screening reduces cancer-related mortality. 

Can an MCED test diagnose cancer? 

No. MCED tests are screening tools, not diagnostic tests.  

A positive result does not mean a person has cancer. Additional imaging, laboratory testing, and clinical evaluations are needed to confirm whether cancer is actually present. Likewise, a negative result does not guarantee that cancer is absent. 

What else should I know about MCEDs? 

According to Dr. Poirier, “MCED tests do not replace mammograms, colonoscopies, Pap tests, or other recommended cancer screenings. They are designed to complement our existing screening programs.” 

“However, outside of the current screening options we have for colon, breast, prostate, HPV, and lung cancer, we have had no other way to screen for other cancer types.”   

Like all screening tests, MCEDs aren’t perfect. While the Galleri test can detect signals associated with more than 50 cancer types, no screening test is 100% accurate. The technology was developed to help identify cancers that are often diagnosed at later stages and for which no established screening programs currently exist. As ongoing studies continue to follow participants over time, researchers will gain a better understanding of the test's long-term clinical impact. 

However, notably, the recent FDA regulatory milestones in the United States represent an important step forward for the technology. The FDA's advisory committee concluded that the benefits of the Galleri test outweigh its risks and supported its safety, although the agency has not yet issued its final approval decision.  

Researchers are also continuing to study whether widespread use of MCED testing ultimately leads to fewer late-stage cancer diagnoses and reductions in cancer deaths. 

Take action 

The Galleri® test by GRAIL sets the standard for multi-cancer early detection and is ideal for those who are seeking a more proactive approach to cancer screening.  Through a single blood draw, this innovative, clinically validated test screens for 50+ cancer types, like pancreatic and ovarian, before they become symptomatic, maximizing the opportunity for early diagnosis, when treatment can be most effective. It is meant to complement, not replace, routine cancer screenings as part of a comprehensive approach to cancer prevention and early detection. Learn more. 

This article was written by Shaun Francis in collaboration with Medcan’s editorial team, Medcan’s innovation team and contribution and approval from Medcan's Vice President of Medical Affairs, Dr. Jason Abrams and Medcan's Clinical Director of Dedicated Care, Dr. Steven Poirier.

The client has given consent to share this story. 

This content is for informational purposes only and should not be taken as medical advice. Please consult a Medcan clinician or your healthcare provider for guidance tailored to your health needs.  

Galleri is a registered trademark of GRAIL, Inc.  

Important Safety Information: The Galleri test is recommended for use in adults with an elevated risk for cancer, such as those age 50 or older. The test does not detect all cancers and should be used in addition to routine cancer screening tests recommended by a healthcare provider. The Galleri test is intended to detect cancer signals and predict where in the body the cancer signal is located. Use of the test is not recommended in individuals who are pregnant, 21 years old or younger, or undergoing active cancer treatment. Results should be interpreted by a healthcare provider in the context of medical history, clinical signs, and symptoms. A test result of No Cancer Signal Detected does not rule out cancer. A test result of Cancer Signal Detected requires confirmatory diagnostic evaluation by medically established procedures (e.g., imaging) to confirm cancer. If cancer is not confirmed with further testing, it could mean that cancer is not present or testing was insufficient to detect cancer, including due to the cancer being located in a different part of the body. False positive (a cancer signal detected when cancer is not present) and false negative (a cancer signal not detected when cancer is present) test results do occur.  

Lab / Test information: The GRAIL clinical laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and accredited by the College of American Pathologists. The Galleri test was developed and its performance characteristics were determined by GRAIL. The Galleri test has not been cleared or approved by the Food and Drug Administration. This test is not Health Canada or FDA approved, and has not been endorsed by any professional medical societies at this time. The GRAIL clinical laboratory is regulated under CLIA to perform high-complexity testing. The Galleri test is intended for clinical purposes.