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New Study Finds Multi-Cancer Blood Test May Detect More Cancers Earlier

Early detection is one of the most powerful tools for improving cancer outcomes, enabling treatment with the goal of cure when cancers are found at earlier stages (such as Stage I or II) that might otherwise be diagnosed later, when cure is less likely. Yet despite its importance, routine screening is currently available for only a few cancer types, including breast, cervical, colorectal, prostate, and lung cancers. For most others, no established screening tests exist, meaning many cancers are discovered only after symptoms appear.

To close this gap, researchers are developing multi-cancer early detection (MCED) blood tests, emerging technologies that look for tiny fragments of circulating tumor DNA (ctDNA) in the bloodstream. These tests can detect whether a “cancer signal” is present and, in many cases, show where in the body the cancer may have originated. Recent results from the PATHFINDER 2 study found that adding Grail’s Galleri® MCED test to standard screenings may help find more cancers and detect them earlier.

Our experts at Private Health Management (PHM) break down what you need to know about these important results.

PHM helps clients navigate emerging screening options like MCED tests, explaining what they measure, arranging access, and helping determine whether they are appropriate based on medical history, risk factors, and overall health needs. PHM also assists in identifying the most appropriate provider (e.g., diagnostic or oncology specialist) and facilitating a diagnostic-workup consultation in collaboration with GRAIL, to support timely and appropriate follow-up of a positive test result

What the PATHFINDER 2 Study Found

The PATHFINDER 2 study, presented in October at the European Society for Medical Oncology (ESMO) 2025 Congress in Berlin, is the largest trial to date of an MCED test in patients already undergoing routine cancer screening.1 Building on results from an earlier study, the trial tested whether adding a single blood test to standard U.S. Preventive Services Task Force (USPSTF)-recommended screenings could safely detect more cancers than screening alone. More than 35,000 adults aged 50 and older from across the U.S. participated.

Highlights from the PATHFINDER 2 Study

FindingWhat it Means
Higher detection ratesAdding the blood test to standard screening found seven times more cancers than screening alone, but only about three additional cases per 1,000 people tested.
Cancers without screening options73% of cancers detected had no existing screening tests, such as pancreatic, liver, head-and-neck, or ovarian cancers.
Earlier detection53.5% of detected cancers were stage I or II, and 69% were stage I–III.
Missed cancersThe test did not identify about 60% of cancers that appeared within a year, highlighting that traditional screenings remain essential.
Tumor-origin predictionAmong cancers the test detected, it correctly identified where in the body the cancer originated in over 90% of cases, helping guide follow-up testing.
Few false alarmsOnly 0.4% of participants received a false-positive result, so very few people underwent unnecessary follow-up testing.
SafetyFewer than 1% (0.6%) needed an invasive procedure (such as a biopsy), and no serious study-related adverse events were reported.

Taken together, these findings show that this MCED test can detect some cancers earlier and identify types not covered by existing screening, but it also missed many cases, underscoring the need for continued use of standard screening tests.

Key Questions and Remaining Challenges

While these findings highlight progress in incorporating MCEDs for cancer screening, several important questions and challenges remain.

  • Impact on outcomes: It is not yet clear whether finding more cancers through MCED testing will reduce cancer deaths, since the study measured detection, not long-term survival.
  • Risk of overdiagnosis: Some cancers detected might never have caused symptoms or harm, raising questions about when and how to treat them.
  • Different Sensitivities: The sensitivity is variable amongst different cancer types and stages, preferentially detecting tumors that shed higher levels of ctDNA at the expense of more indolent, slow-growing tumors.
  • Real-world use: Researchers are still studying how best to use these tests in everyday care, including how to follow up on positive results and assess long-term cost-effectiveness and health outcomes.

Other MCED Tests on the Horizon

Grail’s Galleri® test currently has the largest publicly available clinical dataset in the MCED space, though other MCED technologies are in development which may leverage different analytic approaches or tumor-type coverage. Each uses different technologies and will need to show reliability and real-world benefit before being widely adopted. Tests include:

  • Exact Sciences’ Cancerguard™ analyzes multiple DNA and protein markers to detect over 50 cancer types and subtypes, including many without screening options. It is currently offered in the U.S. as a self-pay lab test for adults ages 50–84 with no recent cancer diagnosis.2
  • Guardant Health’s Shield™ test, already FDA-approved for colorectal cancer, is being expanded to detect additional cancers.3
  • FirstLook Lung (DELFIDiagnostics) uses a “fragmentomics” approach, analyzing patterns in cell-free DNA fragments, to detect lung cancer through a routine blood draw. It is currently available for lung cancer screening and represents the company’s first step toward developing broader multi-cancer early detection tests.4

Cost and coverage: MCED tests are not yet covered by insurance and typically cost about $700–$1,000 out of pocket. Coverage may change as more clinical evidence becomes available.

Who Might Benefit Most

While regulatory review is ongoing, these tests may be especially helpful for high-risk individuals aged 50 and older, including those with a family history of cancer, inherited genetic risk, or other predisposing factors. For some, an MCED test could add a valuable layer of surveillance to complement existing guideline-based screenings. However, experts agree that negative results do not rule out cancer, and traditional screenings remain essential for everyone.

The Bottom Line

MCED tests represent an exciting step toward finding more cancers earlier. The latest data show real potential but also underscore the need for more evidence on how best to use these tests safely and effectively. At PHM, we follow this research closely, helping patients interpret emerging data and apply new technology thoughtfully, as part of a comprehensive approach to cancer prevention and early detection.

References

  1. GRAIL PATHFINDER 2 Results Show Galleri® Multi-Cancer Early Detection Blood Test Increased Cancer Detection More Than Seven-Fold When Added to USPSTF A and B Recommended Screenings. GRAIL https://grail.com/press-releases/grail-pathfinder-2-results-show-galleri-multi-cancer-early-detection-blood-test-increased-cancer-detection-more-than-seven-fold-when-added-to-uspstf-a-and-b-recommended-screenings/.
  2. CancerguardTM Multi-Cancer Early Detection Test | Exact Sciences. https://www.exactsciences.com/cancer-testing/cancerguard-mced-providers.
  3. Guardant Health to Share Data Supporting Critical Role of Blood-Based Testing in Improving Cancer Screening Adherence at ACG 2025. https://investors.guardanthealth.com/press-releases/press-releases/2025/Guardant-Health-to-Share-Data-Supporting-Critical-Role-of-Blood-Based-Testing-in-Improving-Cancer-Screening-Adherence-at-ACG-2025/default.aspx.
  4. FirstLookLung for Patients. DELFI https://delfidiagnostics.com/our-products/firstlooklung-patients/.

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Gareth Morrison

Gareth J. Morrison, PhD

Senior Research Director

Gareth J. Morrison is a Senior Research Director at Private Health Management with more than 15 years of experience in academic and translational research, including the past decade dedicated to advancing cancer research. He specializes in lung, gastrointestinal, and genitourinary malignancies and applies his expertise in precision medicine to support individualized treatment strategies for clients. Before joining PHM, Gareth served as a Specialized Research Advisor at USC Norris Comprehensive Cancer Center, where he established and managed an NCI-designated Liquid Biopsy Core to advance method development and biomarker discovery. At Roswell Park Cancer Institute, he was part of the team that launched the Center for Personalized Medicine, where he developed tumor genomic assays and validated a next-generation sequencing test approved by the New York State Clinical Laboratory Evaluation Program. Gareth earned his PhD in Chemical Biology and a Bachelor of Science in Biochemistry from the University of Edinburgh, UK, and a Master of Science in Regulatory Management from the University of Southern California.
Julie Nowicki

Julie Nowicki, PhD

Science Communications Specialist

Julie is a Science Communications Specialist at Private Health Management, where she collaborates with the Research and Clinical teams to translate complex scientific concepts into clear, accessible information for clients and their families. Her work helps bridge the gap between cutting-edge research and personalized patient care. A scientific and medical writer by training, Julie has developed content for both clinical and patient audiences across a range of therapeutic areas, including oncology, hematology, dermatology, and women’s health. Before joining PHM, she served as a Senior Medical Writer, where she created clinical manuscripts, abstracts, congress materials, and educational resources for pharmaceutical clients. Julie earned her PhD in Cell, Molecular, and Developmental Biology from the University of North Carolina at Chapel Hill.