Bile Cell-Free DNA as a Liquid Biopsy for Biliary Tract Malignancies: A Scoping Review

Background

Biliary tract cancers (BTCs) carry a poor prognosis driven by frequent diagnosis at advanced or metastatic stages. Inadequate tissue sampling impedes biomarker-directed selection of therapy that could potentially improve outcomes over limited chemotherapeutic options. Plasma cell-free DNA (cfDNA) yields limited sensitivity. However, given its direct contact with the tumor, bile holds promise as a locally enriched source of tumor-derived cfDNA for evaluation.