A Cell-free DNA Methylation Blood-Based Test for Biliary Tract Cancers Screening

Biliary tract carcinoma (BTC), including gallbladder cancer, intrahepatic cholangiocarcinoma, and extrahepatic cholangiocarcinoma, ranks sixth in incidence among gastrointestinal malignancies and tenth in cancer-related mortality worldwide. Due to the lack of specific early symptoms, high malignancy, and frequent recurrence and metastasis, the rate of curative resection is only about 16.5%, and the overall 5-year survival rate is less than 5%. Early and accurate detection is therefore critical for improving patient outcomes. Circulating tumor DNA (ctDNA), a fraction of circulating free DNA (cfDNA), carries genetic and epigenetic information from tumor cells and can be detected even at the early stages of cancer development. Among various liquid biopsy biomarkers, ctDNA methylation shows particular advantages in sensitivity and specificity for early cancer detection and monitoring. This study aims to evaluate the application of cfDNA methylation liquid biopsy in the diagnosis and management of BTC.