Routine health checks help identify potential health risks before symptoms appear. The Galleri® Multi-Cancer Early Detection test takes a similar proactive approach to cancer screening, looking for signals of multiple cancer types through a simple blood draw.
Prevention is not just about avoiding illness—it's about optimizing health, improving quality of life and ensuring you're at your best for yourself and your loved ones.
Checking a routine screening off your list can feel like a small act of care for your future self. Mammograms, colorectal screening, and Pap smears/HPV tests offered through provincial programs remain the foundation of cancer screening in Canada. Some people also want to learn about additional options to use alongside their routine screening.
One of those options is the Galleri® Multi-Cancer Early Detection test, developed by GRAIL and now available at TELUS Health Care Centres in Alberta and British Columbia.* Understanding how it works, and what it can and can’t tell you, can help you make an informed decision about whether to add it to your health routine.
How the test works
All cells in the body, healthy or not, release tiny fragments of DNA into the bloodstream as they die and are replaced. . Attached to the DNA are small chemical tags (called methylation) that help control which genes are switched on or off. Cancer cells tend to carry different patterns of these chemical tags than healthy cells do. The test looks for these patterns in the DNA fragments circulating in your blood.
A technology called next-generation sequencing reads the DNA fragments in a blood sample and records their chemical tag patterns. Computer software, trained on samples from people with and without cancer, analyzes the patterns.
The test looks for a signal shared across more than 50 types of cancer, including some that don’t have routine screening guidelines. It is also not a hereditary test and does not predict your future genetic risk for cancer. If it finds such a signal, the test can also predict which tissue or organ the signal may be coming from, such as the pancreas, ovaries and liver. This is called the cancer signal origin.1,2
What can the test tell you?
The test gives one of two results:
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Cancer signal detected means the test found a pattern often associated with cancer. It is not a diagnosis. It means further evaluation is needed to find out whether cancer is present.
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No cancer signal detected means no signal was found at the time of the test. It doesn’t rule out cancer, because false negatives can occur and the test doesn’t detect every type of cancer.
Cancers differ in how much DNA they release into the blood. Some release too little to produce a detectable signal, and the amount varies by cancer type and stage. This is one reason the test does not detect every cancer, and why a ‘no signal’ result cannot rule out cancer.
Where it fits in preventive health, and the journey after a result
Preventive health is layered: healthy habits, regular visits with your healthcare provider, routine screening programs and an understanding of your personal and family risk. A test like Galleri® Multi-Cancer Early Detection is a newer tool in that conversation, intended to be used alongside the rest and never in place of it.
It helps to know what happens after a result. If a cancer signal is detected, TELUS Health will help you navigate next steps.** Confirming a diagnosis requires follow-up diagnostic testing. A ‘Cancer Signal Detected’ result is a prompt for further evaluation, which may include imaging, and the predicted cancer signal origin can help clinicians decide which tests to consider first.
That’s where having a clinician beside you makes a difference. Before you take the test, a clinician can help you understand what it can and can’t tell you. Afterward, they can explain your result, coordinate next steps and keep your primary care provider informed, so you’re not working through unfamiliar medical information on your own.
Disclaimers:
*Important safety information: Galleri® is a private-pay screening test, not a diagnostic tool or replacement for routine provincial cancer screenings. It does not detect all cancers; false positives/negatives occur. Processed by GRAIL in a U.S. CLIA-certified lab; not licensed by Health Canada or the FDA. TELUS Health provides screening navigation, not cancer treatment. Requisition required. Full details, risks, and program terms: telushealth.com/mced-terms
**If a cancer signal is detected, TELUS Health will help ensure you and your primary care provider have the information you need. Primary care providers aren’t obligated to incorporate results from a private, elective screening test into your care plan unless medically warranted, and you’re responsible for follow-up on any results. We encourage you to discuss the Galleri® Multi-Cancer early detection test with your care team.. The test is a laboratory-developed test and is not licensed by Health Canada or the FDA.
Sources:
- Klein EA, et al. Ann Oncol. 2021;32(9):1167-77.
- https://www.galleri.com/what-is-galleri