Scientists at UCLA have developed a test that shows promise in detecting “multiple cancers, various liver conditions, and organ abnormalities simultaneously by analyzing DNA fragments circulating in the bloodstream.”
The method, called MethylScan, works by “analyzing cell-free DNA (cfDNA), tiny fragments of genetic material released into the blood when cells die. Because cells from every organ shed DNA into the bloodstream, cfDNA carries molecular signals that reflect what is happening throughout the body.” Existing tests that scan for mutations in tumor DNA focus on a “limited number of genetic changes and can be expensive;” this new test instead scans for DNA methylation.
Methylation patterns “differ by tissue type and can change when cells become cancerous or diseased.” However, the challenge comes from the fact that 80-90% of cell-free DNA in the bloodstream “originates from normal blood cells.” The researchers built on past work to develop a technique to remove a lot of the background DNA before sequencing.
To test the new approach, the researchers analyzed blood samples from 1,061 people. Three groups – including people with cancer, people with non-cancerous liver disease, and healthy individuals – were tested. The test achieved a “high level of overall accuracy,” returning few false positives and detecting about 63% of cancers across all stages and 55% of early-stage cancers.
