The Festival of Genomics and Biodata, London 2026

Early detection of cancer can greatly improve treatment outcomes. This study explores the 6-base genome, A, C, G, T, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) as biomarkers for early-stage colorectal cancer (CRC) in cell-free DNA (cfDNA) and matched tissue. We recapitulated a study performed by biomodal using whole genome sequencing to analyse untreated CRC patients and healthy controls, focusing on differentially methylated regions (DMRs) in stages I and IV. Combining 5mC and 5hmC measurements significantly improved diagnostic accuracy compared to traditional methods. We found increased 5hmC at stage I and decreased 5mC at stage IV, indicating that 5hmC can effectively track demethylation in tumour development. These findings suggest that distinguishing between 5mC and 5hmC enhances the sensitivity of liquid biopsy tests for early-stage cancer detection.