Researchers at University of California, Los Angeles have developed MethylScan, a simple and low-cost blood test that can detect multiple cancers, liver diseases, and organ abnormalities simultaneously. By analysing DNA fragments circulating in the bloodstream, this innovation aims to improve early diagnosis and enable more comprehensive health monitoring.
The study, published in Proceedings of the National Academy of Sciences, highlights the potential of this test to offer a more affordable and accessible approach to disease detection.
Why Early Detection Matters
Early diagnosis plays a critical role in improving survival outcomes. According to Jasmine Zhou, senior author of the study, detecting cancer at an early stage significantly increases survival rates. In contrast, outcomes worsen considerably once the disease progresses to advanced stages. Therefore, tools like MethylScan could transform how clinicians identify and manage diseases.
How MethylScan Analyses Cell-Free DNA
As reported by SciTech Daily, MethylScan works by examining cell-free DNA (cfDNA), which consists of tiny DNA fragments released into the bloodstream when cells die. Since every organ sheds DNA, these fragments collectively provide a snapshot of activity across the entire body.
Every day, billions of cells die and release DNA into circulation. Consequently, this circulating genetic material carries valuable information about organ health and disease processes, making it a powerful diagnostic resource.
Moving Beyond Mutation-Based Testing
Although liquid biopsy is not new, most existing tests focus on detecting genetic mutations in tumour DNA. However, these approaches often target limited changes and require expensive deep sequencing.
Instead, the UCLA team shifted focus to DNA methylation—a set of chemical markers that regulate gene activity. These methylation patterns vary by tissue type and change when cells become diseased. As a result, they provide a richer and more informative signal about overall tissue health.
Overcoming Background Noise
One major challenge in analysing cfDNA is that 80–90% of it originates from normal blood cells, which creates significant background noise. To address this, researchers developed a novel method to filter out irrelevant DNA.
They used specialised enzymes to remove unmethylated DNA, primarily derived from blood cells. Subsequently, a genome-wide hybridisation panel enriched the remaining sample for methylated DNA from solid organs, including diseased tissues. This approach significantly improves detection accuracy while reducing sequencing requirements.
Cost-Effective and Scalable Technology
By minimising background noise, MethylScan reduces the need for extensive sequencing. The test achieves effective results with a sequencing depth of 300× using only 5 gigabases of data. Consequently, the cost could fall below $20 per test as sequencing becomes more affordable, making it highly scalable for widespread use.
Strong Performance Across Diseases
To validate the test, researchers analysed blood samples from 1,061 individuals, including patients with liver, lung, ovarian, and stomach cancers, as well as those with liver diseases such as hepatitis B, hepatitis C, alcohol-related liver disease, and metabolic-associated liver disease.
At 98% specificity, MethylScan detected approximately 63% of cancers across all stages and about 55% of early-stage cases. Additionally, it showed strong performance in identifying liver cancer in high-risk groups, detecting nearly 80% of cases with over 90% specificity.
Identifying the Source of Disease
Importantly, the test not only detects disease but also identifies its origin within the body. By analysing methylation patterns, MethylScan can trace abnormal DNA signals back to specific organs.
According to Wenyuan Li, this capability is crucial because it helps guide follow-up diagnostics, such as imaging, toward the correct organ.
A Step Toward Non-Invasive Monitoring
Beyond cancer detection, MethylScan functions as a system-wide health monitor. It can identify early signs of organ stress or damage, even before a specific disease is diagnosed.
Moreover, the test demonstrated the ability to distinguish between different liver diseases with about 85% accuracy. This capability could reduce reliance on invasive procedures like biopsies, improving patient comfort and safety.
Moving Toward a Universal Blood Test
Although further large-scale studies are needed, researchers believe MethylScan represents a significant step toward a universal diagnostic tool. By combining affordability, accuracy, and multi-disease detection, it brings medicine closer to a single blood test capable of identifying a wide range of conditions early.
Ultimately, this advancement underscores the growing potential of blood-based methylation profiling to transform disease detection and improve patient outcomes on a global scale.