UCLA Develops Low-Cost Blood Test to Detect Multiple Cancers

LOS ANGELES — Scientists at UCLA have developed a low-cost blood test called MethylScan that can detect multiple types of cancer, liver diseases, and organ abnormalities from a single sample, according to a study published in the Proceedings of the National Academy of Sciences on April 6. The test, which could cost less than $20 in sequencing per sample, represents a significant step toward affordable multi-cancer screening.

The technology works by analyzing DNA methylation patterns in cell-free DNA, the tiny fragments of genetic material that cells shed into the bloodstream when they die. Rather than hunting for rare tumor mutations, the approach traditional liquid biopsies rely on, MethylScan reads chemical tags on DNA that reflect the health status of different tissues throughout the body. The result is a broader diagnostic window from a single blood draw.

How MethylScan Works | Stripping Noise From Blood Samples

The central challenge in cell-free DNA analysis is background noise. Roughly 80% to 90% of the DNA fragments circulating in blood come from normal white blood cells, not from diseased tissue. That overwhelming background makes faint signals from tumors or damaged organs extremely difficult to detect, particularly in early-stage disease when the signal is weakest.

The UCLA team, led by Dr. Jasmine Zhou, a professor of pathology and laboratory medicine, addressed this by developing an enzymatic depletion step. Specialized enzymes strip away unmethylated DNA fragments, the ones predominantly shed by blood cells, before sequencing begins. What remains is enriched for methylated fragments originating from solid organs, where cancer and other diseases leave distinct chemical signatures.

That noise-reduction step has a second benefit: it dramatically reduces the amount of sequencing required. Existing liquid biopsy tests, such as Grail's Galleri, rely on deep whole-genome sequencing to find faint signals buried in noise. MethylScan's enzymatic cleanup means the test can achieve comparable sensitivity with shallow sequencing, bringing estimated costs to under $20 per sample. Galleri, by comparison, is priced at approximately $949 per test.

Clinical Performance | 1,061 Patients, 98% Specificity

In a study of 1,061 individuals, including patients with liver, lung, ovarian, and stomach cancers, as well as people with various liver diseases and healthy participants, MethylScan detected approximately 63% of cancers across all stages at 98% specificity. That specificity threshold means very few false positives, a critical requirement for any screening test deployed at population scale.

For early-stage cancers, where detection matters most but signals are faintest, MethylScan caught roughly 55% of cases at the same 98% specificity threshold. While that figure leaves room for improvement, it compares favorably with existing multi-cancer early detection tests at a fraction of the cost.

Liver Cancer Surveillance | 80% Detection in High-Risk Patients

The test showed particular strength in liver cancer surveillance among high-risk individuals with cirrhosis or hepatitis B. In that subgroup, MethylScan detected nearly 80% of liver cancers at just over 90% specificity. Current screening for liver cancer in high-risk populations relies on ultrasound combined with alpha-fetoprotein blood tests, a combination that misses a substantial fraction of early tumors.

Beyond cancer detection, MethylScan distinguished between different types of liver disease, including viral hepatitis and metabolic-associated liver disease, correctly classifying about 85% of patients. That capability could reduce the need for invasive liver biopsies, which carry risks including bleeding and infection and require specialist interpretation. The ability to differentiate liver pathology from a blood draw alone has significant clinical value, particularly in primary care settings where access to hepatologists and interventional radiologists is limited.

Cost Comparison | $20 vs. $949 Per Test

The economics of MethylScan could be transformative. Multi-cancer early detection is one of the most active areas in diagnostics, but the leading commercial tests remain expensive. Grail's Galleri test costs $949 out of pocket and is not yet covered by most insurance plans. Exact Sciences' CancerGuard and Freenome's platform are in similar price ranges during clinical development.

MethylScan's sub-$20 sequencing cost does not account for sample collection, processing, and interpretation overhead, so the final clinical price would be higher. But even at several times that figure, the test would be an order of magnitude cheaper than current alternatives, potentially making multi-cancer screening viable for routine annual checkups rather than a premium service.

The cost advantage stems directly from the enzymatic depletion step. By removing the dominant blood-cell DNA before sequencing, the team needs far fewer sequencing reads to extract meaningful signal. It is a biochemical solution to what has been treated as a computational and sequencing-depth problem by other groups.

What Comes Next | Prospective Trials and Clinical Validation

"This study demonstrates that blood-based methylation profiling can deliver clinically meaningful information across multiple diseases," said Dr. Zhou. "It's an exciting advancement that brings us closer to realizing the dream of a single assay for universal disease detection."

Larger prospective trials will be needed before MethylScan can move into routine clinical screening. The current study was retrospective, meaning researchers analyzed stored samples from patients already diagnosed. A prospective trial, where participants are tested before diagnosis and followed over time, is the regulatory standard for screening tests seeking FDA approval. That process typically takes three to five years.

The research was supported in part by grants from the National Cancer Institute. UCLA has filed patent applications on the underlying technology, and the team is in discussions with diagnostics companies about licensing and commercialization, though no partnerships have been announced.

The broader landscape of epigenetic medicine is advancing rapidly. Researchers across the field are demonstrating that chemical modifications to DNA, rather than the genetic sequence itself, carry diagnostic and therapeutic information that has been underexploited. MethylScan joins a growing body of work, including CRISPR-based gene therapies and epigenetic reprogramming approaches, that treat DNA as more than a static code.

If prospective trials confirm the retrospective findings, MethylScan's combination of broad detection capability, high specificity, and low cost could make it one of the most consequential diagnostics advances in a generation, not by being the most sensitive test available, but by being the one that health systems can actually afford to deploy at scale.