Overview
- UCLA published a retrospective study in PNAS describing MethylScan, a blood assay that reads cell-free DNA methylation to flag cancers, indicate tissue of origin, and distinguish liver disease types.
- The test uses an enzyme step to remove unmethylated DNA from blood cells and a genome-wide hybridization panel to enrich methylated fragments from solid organs before sequencing.
- In 1,061 samples the assay showed about 98% specificity, detected roughly 63% of cancers overall and about 55% of early-stage cancers, and found nearly 80% of liver cancers in high-risk patients at just over 90% specificity.
- Researchers say the approach reduces required sequencing to about 5 gigabases per sample and estimate costs below $20 per sample if sequencing prices stay under $4 per gigabase, noting that this is conditional on those price assumptions.
- Authors and funders emphasize these are early, retrospective results and that larger prospective trials and real-world validation are under way to measure screening effectiveness, false-negative rates, and appropriate follow-up after a positive test.