UCLA scientists have developed a blood test that shows early promise in detecting multiple cancers and various organ conditions from a single sample by analysing DNA fragments circulating in the bloodstream. The findings were published in Proceedings of the National Academy of Sciences.
The method, called MethylScan, analyses cell-free DNA (cfDNA) – genetic material released into the blood when cells die. Rather than searching for genetic mutations, the test examines DNA methylation patterns, chemical tags that regulate gene activity and differ by tissue type, changing when cells become cancerous or diseased.
A key challenge is that 80 to 90% of cfDNA originates from normal blood cells, creating background noise. To address this, researchers developed a technique using specialised enzymes to selectively remove unmethylated DNA fragments from blood cells, enriching samples for methylated DNA from solid organs. This reduces sequencing requirements and costs whilst maintaining sensitivity.
The team tested MethylScan on blood samples from 1,061 individuals, including patients with liver, lung, ovarian, and stomach cancers, various liver diseases, benign lung nodules, and healthy participants. At 98% specificity, the test detected approximately 63% of cancers across all stages and 55% of early-stage cancers. For liver cancer surveillance in high-risk individuals, detection reached nearly 80% at over 90% specificity.
The methylation patterns also helped identify tissue of origin – important for directing follow-up imaging to the correct organ. Additionally, the test distinguished between different liver disease types with approximately 85% accuracy, potentially reducing the need for invasive biopsies.
Senior author Dr Jasmine Zhou noted that larger prospective trials are needed but described the work as an important step towards affordable, comprehensive disease screening.
Source: Medical Xpress / UCLA (PNAS, 2026)
The method, called MethylScan, analyses cell-free DNA (cfDNA) – genetic material released into the blood when cells die. Rather than searching for genetic mutations, the test examines DNA methylation patterns, chemical tags that regulate gene activity and differ by tissue type, changing when cells become cancerous or diseased.
A key challenge is that 80 to 90% of cfDNA originates from normal blood cells, creating background noise. To address this, researchers developed a technique using specialised enzymes to selectively remove unmethylated DNA fragments from blood cells, enriching samples for methylated DNA from solid organs. This reduces sequencing requirements and costs whilst maintaining sensitivity.
The team tested MethylScan on blood samples from 1,061 individuals, including patients with liver, lung, ovarian, and stomach cancers, various liver diseases, benign lung nodules, and healthy participants. At 98% specificity, the test detected approximately 63% of cancers across all stages and 55% of early-stage cancers. For liver cancer surveillance in high-risk individuals, detection reached nearly 80% at over 90% specificity.
The methylation patterns also helped identify tissue of origin – important for directing follow-up imaging to the correct organ. Additionally, the test distinguished between different liver disease types with approximately 85% accuracy, potentially reducing the need for invasive biopsies.
Senior author Dr Jasmine Zhou noted that larger prospective trials are needed but described the work as an important step towards affordable, comprehensive disease screening.
Source: Medical Xpress / UCLA (PNAS, 2026)
