Cancer is frightening. Simply as a word for many. It has something beyond ominous about it. So discussing it might not be the jolliest of subjects but it can save lives. So buckle up beacuse catching the disease early can make a significant difference in quality of life and survival rates. Many cancers, when diagnosed early, are far more treatable, giving patients a much better chance at leading longer lives.
New technologies in multi-cancer detection tests (MCDs), such as Galleri and Delfi, are showing real promise in helping identify cancers earlier, sometimes even before symptoms begin. So we thought to have a look and see how good are these new systems and how can we use them to improve our lives.
In short, do they live up to the hype?
The Rise of Liquid Biopsies in Cancer Screening
Traditionally, cancer screening has been specific to one type of cancer at a time. Common examples are mammograms for breast cancer or colonoscopies for bowel cancer. This means limited opportunities to catch other cancers. However now things are changing. The development of liquid biopsy technologies is disrupting this model entirely. Liquid biopsies are non-invasive tests that analyse blood, urine, saliva, or other bodily fluids for markers of cancer.
These tests are being adapted to detect multiple cancers simultaneously. That means multi-cancer tests (MCTs). Private clinics are increasingly adopting these tests, providing access to people eager to benefit from early detection.
Multi-cancer detection tests are tools that can identify several cancers from a single sample, usually of blood. Tests such as Galleri and Delfi are the ones leading the way. They work by detecting small fragments of DNA released by cancer cells into the bloodstream. Each of these fragments can carry clues about the presence and even the location of cancer in the body. A very important development.
As a first example the Galleri test uses next-generation sequencing. It analyses the methylation patterns of DNA. This a process that helps determine if the DNA is from a cancer cell and, if so, from which type of tissue it originated. It can detect over 50 different types of cancer. Including those for which there are currently no routine screening methods, such as pancreatic, oesophageal, and ovarian cancers. This is a huge step forward.
The second example is the Delfi test, which also uses blood samples but focuses on detecting unusual fragmentation patterns in the DNA released by tumours. Delfi aims to use machine learning algorithms to help improve the accuracy of these detections. Although it is still in the early stages of clinical validation compared to Galleri, it has shown a lot of promise.
Multi-Cancer Tests Can Change Population Screening
The use of multi-cancer detection tests is primarily focused on screening people who are asymptomatic. Those who appear healthy but might have a hidden cancer developing. Known as multi-cancer early detection tests (MCEDs), these tools could change the landscape of population screening. Currently, most screening programmes only detect a single type of cancer. The Galleri test, for example, could enable the screening of numerous cancers at once, allowing doctors to catch not just the more common types but also rarer cancers that often go undiagnosed until it is too late.
If this is done on large parts of the population, the amount of cancers caught early can rise very significantly. This will lead to much better treatment and also increased resources. However, one thing is very possible, that the survival rate will increase significantly, making cancer a manageable disease, rather than what it currently usually is. A fatal one.
The ongoing NHS-Galleri trial in England is right now testing Galleri in over 140,000 people aged between 50 and 77. They are assessing whether using the test alongside NHS standard screening can reduce the number of late-stage cancer diagnoses. This trial aims to provide valuable data on whether multi-cancer detection can improve patient outcomes. Full results are expected by 2026.
The primary advantage of MCEDs like Galleri and Delfi is early detection. Identifying cancer at an early stage means more treatment options, often with less intensive approaches. Dr Charles McDonnell, a key figure in the PATHFINDER trial, noted:
“The more broadly we can get the message out about multi-cancer early detection technology… the better for our patients”. – Dr Charles McDonnell
Another benefit is non-invasiveness. Unlike traditional biopsies or procedures like colonoscopies, these tests require only a blood draw. This convenience could make more people willing to participate in screening. That will catch cancers that would otherwise be missed.
However, there are still challenges. One of the main issues is ensuring that these tests are both highly sensitive. Meaning that they are correctly identifying people with cancer. They also have to be specific in correctly identifying those without it. False positives, where the test wrongly indicates cancer, can cause significant anxiety and lead to unnecessary further testing. False negatives, meanwhile, might give a false sense of security.
There is also the risk of overdiagnosis. This is when cancers are detected that would never have caused harm during a person’s lifetime. This can lead to overtreatment, which has its own risks and side effects. In addition to all of the above, the cost and availability of these tests are current barriers. They are mostly offered through private clinics at present and may not be accessible to everyone.
New Cutting-Edge Cancer Diagnosis Tests
| Test Type | Technology/Method | Target Cancers | Key Advantages | Current Status |
| Multi-Cancer Blood Tests (MCEDs) | cfDNA analysis (fragmentomics, methylation), protein biomarkers, AI analysis. | Multiple cancers (often 50+), including those without standard screening. | Potential for earlier detection, less invasive than biopsies, single blood draw. | Ongoing clinical trials, some tests (e.g., Galleri) available with prescription. |
| Liquid Biopsies (Circulating Tumor DNA – ctDNA) | Analysis of ctDNA fragments in blood. | Specific cancers based on biomarker detection. | Monitoring treatment response, detecting recurrence, identifying actionable mutations. | Clinical use for some cancer types, expanding application. |
| Advanced Imaging (PET/MRI Hybrid) | Simultaneous PET and MRI scans. | Various cancers, particularly those with complex anatomical locations. | Improved accuracy, detailed anatomical and functional information. | Availability increasing in specialized centers. |
| Breath Tests (Volatile Organic Compounds – VOCs) | Analysis of VOCs in exhaled breath. | Lung, colorectal, and other cancers. | Non-invasive, rapid, potentially cost-effective. | Early stages of development, showing promising results. |
| Optical Imaging (Endoscopy with AI) | High-resolution endoscopy combined with AI image analysis. | Colorectal, gastrointestinal cancers. | Improved detection of polyps and early-stage lesions. | Clinical implementation growing, AI enhancements ongoing. |
| MicroRNA (miRNA) Analysis | Detection of specific miRNA signatures in blood or other fluids. | Various cancers, including lung, breast, and prostate. | Potential for high sensitivity and specificity. | Research and early clinical trials. |
| Nanotechnology-Based Sensors | Nanoparticles that detect specific cancer biomarkers. | Various cancers, including early-stage detection. | Enhanced sensitivity, potential for point-of-care testing. | Research and preclinical development. |
| Epigenetic Biomarker Assays | Analysis of epigenetic changes (e.g., DNA methylation) in blood or tissue. | Various cancers, especially those with epigenetic alterations. | Potential for early detection and risk stratification. | Research and clinical trials. |
| CRISPR-Based Diagnostics | CRISPR-Cas systems for sensitive detection of cancer-related DNA/RNA. | Various cancers, potential for rapid and point-of-care testing. | High sensitivity and specificity, rapid results. | Early stages of development and clinical trials. |
| Tumor-Educated Platelets (TEPs) testing | Analysis of altered RNA within platlets that have come into contact with tumors. | Various cancers. | Minimally invasive. Early detection. | Early stages of development. |
A Look to the Future
The future for multi-cancer detection tests is promising. Ongoing large-scale studies like the PATHFINDER 2 trial and the NHS-Galleri trial are crucial to understanding how well these tests work in different populations. And how they can be integrated into national screening programmes. Once these tests are fully validated, they could become an integral part of regular health check-ups, particularly for those at higher risk.
Importantly, by catching cancers before they spread, these tests hold the potential to improve survival rates significantly. As Bob Ragusa, CEO of GRAIL, commented, “We will continue our generation of additional performance, safety, and clinical utility data to support the adoption of these technologies more widely”. With early evidence showing the potential for these tests to catch multiple cancers at early, treatable stages, the future of cancer detection looks increasingly hopeful. And what a change that is from this diseases’ trecherous past.