Galleri Multi-Cancer Test: Blood-Based Technology Could Detect Some Cancers Earlier

Finding cancer early and treating it gives people the best chance at a good outcome. Routine screenings like mammograms can detect breast cancer, Pap smears can detect cervical cancer, skin checks can detect melanoma and colonoscopies can detect pre-cancerous lesions in the colon or colorectal cancer. But there are only screening tests available for a small number of cancers. Many cancers have no recommended screening, which means they are often detected in more advanced stages and when there are fewer treatment options. Medical researchers and doctors are excited about the use of blood-based technology to screen for many cancers at once, with just a single blood draw. 

How Blood-Based Technology Works 

When cancer cells grow in the body, the immune system has natural mechanisms to scavenge for those cells and prevent them from becoming clinically significant cancer. When those cells die, they release small fragments of DNA into the bloodstream. The DNA fragments have different chemical signatures from normal body DNA — it is methylated — a chemical modification that attaches one carbon and three hydrogens elements to the DNA molecule. Methylated DNA indicates possible cancer. 

“With blood-based technology, we can analyze a blood sample for methylated DNA and then sequence that DNA to give us a good idea of what organ or tissue it comes from,” said Mark Lodes, MD, Froedtert & MCW internal medicine physician and vice president and chief medical officer for Froedtert & MCW Population Health and Medical Education. 

By studying the genomics of the DNA fragment, blood-based technology is able to pinpoint where in the body the cancer originated, for example in the prostate or gastrointestinal system. This information is then used by doctors to pursue further testing and imaging. 

“Blood-based technology doesn’t replace routine screenings, but it is a possible add-on,” said Dr. Lodes “It isn’t as sensitive and specific for each type of cancer, but it does test for the more than 50 cancers that we currently cannot screen for because no test exists.” 

Blood-based technology can identify cancers with solid tumors as well as cancers of the blood, bone marrow or lymphatic system. 

Galleri^® Multi-Cancer Early Detection Screening Test 

The Galleri multi-cancer test, developed by GRAIL, uses blood-based technology to detect cancers. The test is able to identify some of the more aggressive types of cancers that are often detected in late and end stages, such as pancreatic, liver and ovarian cancer. It is available to people though the Froedtert & MCW health network, and it simply requires a doctor’s order for a blood draw. Primary care doctors may recommend the test for their patients who are 50 or older. This subset of the population is at a higher risk of developing cancer as they age. 

Millions of people around the world have taken the Galleri test as part of ongoing clinical trials. Recent data from Galleri shows the test is very accurate and rarely incorrectly identifies indications of cancer, with a false positive rate of 0.4%. A low false positive rate helps to minimize unnecessary diagnostics and can put the person taking the test at ease, allowing them to feel confident the result is correct. A positive test result does not necessarily mean cancer is present, but it should prompt further diagnostic tests. 

“The accuracy of the test varies by type of cancer and stage,” Dr. Lodes said. “You can break the numbers down as far as how often it picks up on stage II, III or IV cancers and by tumor type.” 

According to Galleri, the test is highly sensitive and accurately predicted the cancer location in 93.4% of cases. 

Taking the Galleri Test 

When Officer Cody Lerum with the Appleton Police Department had the opportunity to take the Galleri test, he didn’t hesitate. A fellow officer and veteran had recently passed away due to pancreatic cancer. Pancreatic cancer is often diagnosed at Stage IV, once the cancer has already spread to other organs. It is difficult to treat, and there is no routine screening for it. The officer’s passing was a difficult loss for the community. His loved ones fundraised to cover the cost for other veterans who work in the Appleton Police and Fire Departments to take the Galleri test and potentially catch cancer in its early stages. 

Officer Lerum was a Specialist in the U.S. Army and served in Afghanistan in 2012 and 2013. Now, he is a school resource officer at Appleton East High School. Officer Lerum, along with 18 other first responders who are veterans in the Appleton area, were able to take the test through the Froedtert & MCW health network in late 2024 with a blood draw at the police station. Officer Lerum’s Galleri results came back negative. 

“There is certainly a little anxiety around what your test results could show, but I would much rather know so I could potentially get treatment sooner,” Officer Lerum said. “Getting ahead of a diagnosis like this could ultimately be what saves your life.” 

The Galleri test is going through the FDA approval process. The application requests approval for a once-a-year test for people 50 and older. Right now, the cost is $749 out-of-pocket. With FDA approval, this is expected to change, and insurance companies would likely cover some of the cost. 

Learn More About the Galleri Test