A new blood test, known as Galleri, is making headlines in the world of cancer detection, promising to revolutionize how doctors screen for the disease. Developed by GRAIL, Inc., a biotechnology company based in Menlo Park, California, the Galleri test claims to detect more than 50 types of cancer from a single blood sample. On October 21, 2025, results from a large clinical trial were presented at a European medical conference and widely reported by outlets including Fox News and Channel 9 Eyewitness News, sparking both optimism and debate in the medical community.
The study, which analyzed data from about 23,161 participants aged 50 and older across the United States and Canada, was designed to evaluate the effectiveness of the Galleri test when combined with standard cancer screening methods. All participants were asymptomatic and underwent the standard screenings recommended by the U.S. Preventive Services Task Force—such as those for breast, cervical, colorectal, and lung cancer—alongside the Galleri blood test.
The trial’s findings were eye-catching. According to Fox News, the Galleri test detected a cancer signal in 216 participants, and of those, 133 cases were confirmed as true cancers. This translates to a positive predictive value of 61.6%, meaning that out of those who tested positive, about three out of five actually had cancer. What’s more, the false positive rate was impressively low at just 0.4%, a reassuring statistic for anyone worried about unnecessary anxiety or invasive follow-up procedures.
One of the most striking results was the dramatic increase in cancer detection rates when the Galleri test was used alongside standard screening. Channel 9 Eyewitness News reported that standard screenings alone identified only 20 cancer cases, while the addition of Galleri boosted the count to 133 confirmed cases. That’s more than a sevenfold increase—an outcome that has left researchers and clinicians both excited and cautious.
Dr. Nima Nabavizadeh, an associate professor of radiation medicine at Oregon Health & Science University and a study investigator, told Fox News Digital, “I was incredibly encouraged by these findings and what they may mean for filling unmet screening needs and detecting cancer early.” He emphasized that a positive Galleri test should be “taken seriously,” noting that the experimental test was able to accurately pinpoint the organ of origin for the cancer signal 92% of the time. That’s no small feat, considering the complexity of cancer biology.
Early detection is a game changer in cancer care, and the Galleri test seems to deliver on that front. More than half—53.5%—of Galleri-detected cancers were found at Stage 1 or 2, when treatment is most effective. In fact, 69.3% were detected at Stages 1 to 3, giving patients a better shot at successful outcomes. Even more impressive, about three-quarters of the cancers identified by Galleri currently have no standard screening options in the U.S. This means the test is catching cancers that would otherwise go unnoticed until much later, often when they’re harder to treat.
Dr. Josh Ofman, president of GRAIL, highlighted the significance of these results in a press release. “Adding Galleri to standard screening can help target new cancers in early stages, as most deadly cancers are found too late,” he said. “Galleri’s ability to accurately predict where in the body the cancer signal comes from also helps to guide a more efficient diagnostic workup.” He went on to note, “Galleri is the only MCED (multi-cancer early detection) test available that has been validated in an interventional trial in the screening population and could transform how we deliver cancer screening at a population level.”
But while the enthusiasm is palpable, experts urge caution. Dr. Nicole Saphier, a Fox News medical contributor and associate attending of radiology at Memorial Sloan Kettering Cancer Center, was not involved in the study but weighed in on its implications. She observed, “Early detection saves lives while lowering the overall cost of cancer care by finding the disease when it’s most treatable. [This] allows patients to live longer, healthier and more productive lives.” Saphier added that the Galleri test “adds a promising new layer to existing tools for breast, cervical, colorectal and lung cancer screening, potentially catching cancers that standard tests may miss.”
Yet, Saphier was quick to point out that Galleri is not a replacement for current screening methods. “While it shows promise, this new test is meant to complement, not replace, the currently available screenings,” she said. She stressed the need for “thoughtful, evidence-based integration” to ensure the test improves outcomes without adding unnecessary costs or confusion. As she put it, “As cancers rise among younger people, the question now is whether we should broaden screening ages and if this blood test could play a role in that shift.”
The trial itself was an initial analysis, with only a one-year follow-up so far. Dr. Nabavizadeh acknowledged the limitations, stating, “We are anxiously awaiting the results of the randomized NHS-Galleri test to provide additional clinical utility data as compared to standard of care screening alone.” The study did not directly compare the Galleri group to a true control group under identical conditions, making it difficult to determine the full benefit of the test in a real-world setting. As the press release noted, “Test performance metrics do not represent results of a head-to-head comparative study.”
There are also regulatory hurdles to consider. The Galleri test is currently available by prescription, but it is not approved or cleared by the FDA for all uses. Channel 9 Eyewitness News emphasized that its results should be interpreted alongside other recommended screenings, not as a standalone diagnostic tool. Experts continue to debate whether the benefits of early detection with Galleri justify potential harms, such as overdiagnosis or unnecessary follow-ups, and whether the costs make sense for widespread adoption.
Despite these questions, the Galleri test marks a significant step forward in the quest to catch cancer early. Its ability to detect dozens of cancers—many with no current screening options—at earlier, more treatable stages could have profound implications for public health. The upcoming results from the ongoing trial, which will eventually include a full analysis of 35,000 participants, are eagerly awaited by the medical community.
For now, Galleri offers hope and a glimpse into a future where a simple blood test might one day help save countless lives by finding cancer before it’s too late. The medical world is watching closely, weighing both the promise and the challenges of this new frontier in cancer detection.
