*Source: https://www.years.co/en/liquid-biopsy-vs-krebsfrueherkennung* Two procedures, two evidence tiers # Liquid biopsy or established cancer screening? The question is usually framed as a choice. It is not one, and it cannot be: neither replaces the other. This page explains why, and what the largest trial of this class of test actually found. Free intro call Book appointment 140.000+ participants in the NHS-Galleri trial 4 in 10 positive results with a cancer diagnosis (PATHFINDER) Tier 3 evidence tier of liquid biopsy at YEARS The short answer ## Not a replacement, a different category Established cancer screening targets one specific cancer in a defined group at fixed intervals, and for several of those programmes a reduction in disease-specific mortality is established. A liquid biopsy looks for signals in the blood across many tumour entities. That evidence is missing here. That is why liquid biopsy sits at evidence tier 3 here and established screening at tier 1. This is not a dismissal of the procedure but its correct classification. Weighing the two against each other is the wrong question. ## The comparison across five dimensions Dimension | Established screening | Liquid biopsy | Purpose | Find one specific cancer in a defined age group earlier, at fixed intervals. | Look for signals in the blood across many tumour entities, without committing to one organ. | Evidence tier at YEARS | Tier 1. For several programmes a reduction in disease-specific mortality is established. | Tier 3, research-adjacent. No evidence of a mortality reduction, and it triggers no treatment here. | What an abnormal result means | A defined work-up pathway with established follow-up examinations, described in guidelines. | A search signal without a fixed location. In the PATHFINDER study roughly four in ten positive results actually led to a cancer diagnosis. | What a normal result means | Reassurance for the cancer examined until the next interval, not beyond it. | Considerably less than it feels like. Many early tumours shed too little material into the blood to be detected. | Substitutability | Not substitutable. Colonoscopy, mammography and the other programmes remain indicated regardless. | Complementary, never a replacement. Skipping established screening because of a normal blood test reduces safety rather than increasing it. | What the studies show ## Four points the debate often leaves out ### NHS-Galleri: primary endpoint missed The largest trial of a multi-cancer test so far covered more than 140,000 participants. The primary endpoint was missed. That is the reference point for this class of test, and it shows above all how long the road is from a measurable signal to a demonstrated benefit. ### Performance data do not transfer Galleri reads methylation patterns in cell-free DNA; other procedures look for circulating tumour cells. These are different measurement principles. Numbers from one study apply to the test examined, never to the category. Anyone quoting a sensitivity has to say which test they mean. ### Established screening is not flawless either The comparison would be unfair if it only scrutinised one side. Established programmes also produce overdiagnosis, false positives and effect sizes smaller than expected. The randomised NordICC trial of colonoscopy showed exactly that. The difference is not perfection but that these programmes have been tested in randomised trials at all. ### Why we use it anyway Because it can measure something no other procedure in our programme measures, and because we supply the interpretation. A result is documented and discussed, on its own it triggers no treatment, and it does not change the recommendation for established screening. Under those conditions it is a research procedure within the programme, not screening. The full evidence classification of every procedure is on our evidence page . How often broad diagnostics produces incidental findings is set out on incidental findings . Sources ## Studies this page refers to - NHS-Galleri, primäre Ergebnisse, ASCO 2026 (Abstract LBA100) More than 140,000 participants, primary endpoint missed. Reference point for this class of test and the basis for the statement that a mortality reduction is not established. - Schrag D. et al., PATHFINDER, The Lancet 2023 Basis for the statement that roughly four in ten positive results actually led to a cancer diagnosis. - Multi-cancer early detection tests for general population screening, NIHR HTA 2024 Health technology assessment of the entire class of tests in a general-population screening context. - Bretthauer M. et al., NordICC, N Engl J Med 2022 Randomised trial of colonoscopy. Basis for the statement that established programmes can show smaller effect sizes than expected. ## Common questions Does a liquid biopsy replace established cancer screening? + No, and that is the most important statement on this page. Established screening sits at evidence tier 1 here, because a reduction in disease-specific mortality is established for several programmes. Liquid biopsy sits at tier 3, research-adjacent: it measures signals in the blood, and evidence of a mortality reduction is missing. In the largest trial of a multi-cancer test so far, with more than 140,000 participants, the primary endpoint was missed. Anyone skipping colonoscopy or mammography because of a normal blood test has reduced their safety, not increased it. What does a positive result mean? + A search signal, not a diagnosis. In the PATHFINDER study, roughly four in ten positive results actually led to a cancer diagnosis. Put the other way: six in ten people with a positive result went through a work-up that ended without cancer. That work-up costs time, money and nerves and carries risks of its own. On top of that, the signal initially names no location, so the search has to start broadly. This is why the question of what a positive result would set off for you belongs before the examination, not after it. How reliable is a normal result? + Less reliable than it feels. A multi-cancer test only finds what sheds enough material into the blood. Very early and small tumours often do not, and those are precisely the cases where early detection would make the biggest difference. A normal result therefore does not rule out cancer. It is a snapshot of a signal, not an examination of the body. In practice: symptoms still need working up, and established screening continues at its intervals regardless of the test result. Are all liquid biopsy tests the same? + No, and this is frequently overlooked. Different procedures measure different things: some read methylation patterns in cell-free DNA, others look for circulating tumour cells. These are different measurement principles with different strengths and weaknesses. Performance data from one study therefore apply only to the test examined there, never to the category. When a provider quotes a sensitivity, the first question is which study and which test the number comes from. If there is no clear answer, the number is not usable. So why does YEARS offer liquid biopsy at all? + Because it measures something no other procedure in our programme measures, and because we use it under clear conditions. It is flagged here as a research-adjacent procedure, a result is documented and medically interpreted, and on its own it triggers no treatment. Above all it does not change the recommendation for established screening. Anyone selling it as a substitute for colonoscopy or mammography goes well beyond the evidence. We do not, and this page exists partly so that the distinction can be read back. ## Read on The procedures individually, under the same classification as here. Liquid biopsy Multi-cancer detection as a research-adjacent procedure, not a screening substitute. Cancer screening Established screening with its intervals and target groups. Evidence Three evidence tiers assigned to every procedure, with study status. Incidental findings How often broad diagnostics finds something nobody was looking for. Whole-body MRI The imaging counterpart, with the same open classification. Family history When a family history genuinely changes screening. ## Unsure what belongs together in your situation? 15 minutes, free of charge. We go through which screening is indicated for you and what an additional procedure realistically contributes. Free intro call (15 min) Reserve appointment ★ 4,9 · 71+ Google- reviews · PKV, Beihilfe & bKV reimbursable Medical Disclaimer This information is provided for general education and is not a substitute for professional medical advice, diagnosis or treatment. Please discuss findings and individual medical decisions with a qualified physician. Content is reviewed periodically against the current state of scientific evidence.