“No cancer signal detected.” A man sighs in relief as his phone delivers the result of a single blood test.
In February 2026, a Super Bowl advertisement by Hims & Hers promoted Galleri, a blood-based multi-cancer early detection (MCED) test, promising that a single blood draw could screen for more than 50 types of cancer. The idea is undeniably appealing. A simple test that could catch disease early across a wide range of conditions, offering reassurance or a critical head start on treatment.
However, recent results from the NHS-Galleri trial have now cast doubt on the promise of broad multi-cancer detection. The study found no statistically significant reduction in late-stage cancer diagnoses among participants screened with Galleri, raising questions about whether casting a wide net for dozens of cancers can deliver meaningful patient outcomes.
These realities raise a fundamental question in the field of blood-based cancer screening: is it more effective to cast a wide net, screening for dozens of cancers at once, or to focus narrowly, developing highly sensitive tests for individual high-risk cancers?
The trade-offs of breadth versus depth
The appeal of MCED tests like Galleri is obvious. With a single blood draw, dozens of cancers could be detected early. In theory, this could fill a major gap in current screening programs, which target only a handful of cancers and leave most cancer types without reliable early detection tools.
Galleri has shown promise in this role. In the PATHFINDER 2 study, which enrolled over 35,000 adults aged 50 and older, adding Galleri to standard US-recommended screenings increased cancer detection more than seven-fold, with over half of the newly detected cancers found at early stages. The test also correctly predicted the tumor’s location in 92 percent of cases, helping to streamline the diagnostic follow-up process. However, early findings from the NHS-Galleri trial suggest that earlier detection did not produce a measurable shift in the overall stage at diagnosis, a crucial benchmark for understanding a test’s potential impact on patient outcomes.
"While there were encouraging signals, it did not show a clear reduction in late-stage cancers," Jason Hafron, Chief Medical Officer and Medical Director of Clinical Research at Michigan Institute of Urology, told DDN. "The technology is promising, but we’re not yet at the point where it can serve as a population-wide screening solution."
Although the clinical reliability of blood tests is improving, one of the reasons liquid biopsy tests are not yet used as standalone diagnostics is their sensitivity limitations across cancers and stages, especially for early-stage cancers, which restrict their use as independent diagnostic tests.
—Victor Nwankwo, Texas A&M University
While Galleri has demonstrated an ability to detect a broad range of cancers, MCED tests like it face biological, technical, and healthcare-system challenges that can blunt their impact at the population level. In asymptomatic populations, these tests rely on detecting tumor-derived biomarkers circulating in the blood. However, tumors vary widely in how much DNA they shed, and some cancers may release detectable fragments only once the disease has progressed. Expanding a single assay to cover dozens of cancer types can also dilute sensitivity for any individual cancer, increasing the risk of missed early-stage disease. Even with high specificity, false positives can generate unnecessary anxiety, diagnostic procedures, and healthcare costs for individuals who ultimately do not have cancer.
“Although the clinical reliability of blood tests is improving, one of the reasons liquid biopsy tests are not yet used as standalone diagnostics is their sensitivity limitations across cancers and stages, especially for early-stage cancers, which restrict their use as independent diagnostic tests.” Victor Nwankwo, a pharmaceutical sciences researcher at Texas A&M University, told DDN.
By contrast, a more focused approach allows for fine-tuning to maximize both sensitivity and specificity. Targeted tests can be calibrated to detect subtle biological signals unique to that cancer, improving the likelihood of identifying disease at a truly actionable stage. For clinicians, this depth of performance can provide clearer guidance and greater confidence when evaluating high-risk patients.
This is not to say that broad tests are without value. MCED assays can play an important role in population-level screening, particularly for cancers that currently lack any standard early detection methods. Even if individual sensitivities are lower than those of focused assays, identifying previously undetectable cancers across a wide population could translate into meaningful increases in early-stage diagnoses and, potentially, better chances at recovery.
"Multi-cancer detection has the potential to transform how we address cancers that currently lack practical screening options," Samuel Levy, Chief Scientific Officer at ClearNote Health, told DDN. "Many of the highest-mortality cancers remain unscreened today, and earlier detection in these populations represents one of the largest unmet needs in healthcare.
Difficult to detect cancers
One of the cancers most urgently in need of better early detection is pancreatic cancer. Although it accounts for only about three percent of all new cancer cases in the US, it is projected to become the second leading cause of cancer death by 2030. Most diagnoses occur at a late stage — about 87 percent — when treatment options are limited, and the five-year survival rate for advanced disease can be as low as 0.5 percent. Early detection can make a critical difference, with stage 1 pancreatic cancers having a much higher five-year survival rate of approximately 32 percent.
"Blood-based cancer tests are an exciting development, especially for cancers that currently don’t have good screening tools, such as pancreatic or ovarian cancer,” Daniel Landau, oncologist, hematologist, and expert contributor at The Mesothelioma Center, told DDN. “Right now, we often don't have a way to test for these until symptoms develop, which is often when they are advanced. If these tests prove accurate enough, they could help detect cancer earlier, when treatment is more likely to be effective. That could potentially improve outcomes and make screening easier for patients, since a simple blood test is much less invasive than many traditional tests.”
Current tools for detecting pancreatic cancer in the blood are limited. The most widely used marker is CA 19-9 (cancer antigen 19-9), a protein produced by a range of cancers in the digestive tract. Physicians typically use it to monitor disease progression, treatment response, or recurrence after diagnosis. However, not all pancreatic cancers produce CA 19-9, and elevated levels can also occur in a range of benign conditions, including gallstones, pancreatitis, liver disease, and bile duct infections.
Several institutions are now looking into blood tests for pancreatic cancer that can provide higher sensitivity and specificity. One example is the Avantect Pancreatic Cancer Test from ClearNote, which uses a multiomics approach to analyze blood samples. Rather than relying on a single biomarker, Avantect examines cell-free DNA (cfDNA) for both epigenomic and genomic signals, integrating these with a glycan biomarker to create a thorough molecular profile.
Levy explained, “No single biomarker is sufficient for accurate early detection. By combining multiple signals and analyzing them through machine learning, we detect very small but relevant signals and gain a richer understanding of pancreatic cancer biology.”
In recent updates, the test reportedly achieved approximately 76 percent sensitivity for early-stage disease and over 97 percent specificity, a substantial improvement over existing non-invasive diagnostics. The test has been selected for the SAFE-D trial in the UK, which is evaluating its performance in individuals with new-onset diabetes — a population with a heightened risk for pancreatic cancer. It is also being incorporated into the international Pancreatic Cancer Early Detection (PRECEDE) Consortium, a multi-center effort aimed at advancing earlier diagnosis and risk-stratified screening for people with familial or genetic predispositions to pancreatic cancer.
Looking ahead
Both single-cancer and multi-cancer blood tests are advancing rapidly, but careful clinical validation is essential. Avantect offers a model of targeted, validated testing for a difficult-to-diagnose condition in high-risk populations, while Galleri demonstrates the potential of broader population screening. MCEDs, particularly for cancers lacking standard screening, could transform early detection, but widespread adoption will require solid evidence, regulatory approval, and integration into clinical guidelines.
“For these tests to become widely adopted, we still need stronger evidence showing that they actually lead to earlier diagnoses and fewer cancer deaths,” Landau said. “We also need clear guidelines for how doctors should act on the results. The science is moving quickly, but careful validation is essential to make sure these tests truly benefit patients.”
The coming years are likely to bring significant advances on both fronts. As machine learning models grow more sophisticated and biomarker databases expand, both single-cancer and multi-cancer tests will become more sensitive, more specific, and better validated across diverse populations. The NHS-Galleri results are a course correction, not a verdict — they highlight where the science needs to mature, rather than undermining the fundamental promise of MCEDs.
What is clear is that the era of catching cancer through symptoms alone is drawing to a close. Whether through a targeted test for a high-risk individual or a broad screen at a routine check-up, the tools to detect cancer at its most treatable are within reach — and the field is moving faster than ever to put them in clinicians' hands.
