Advancing Cholangiocarcinoma Diagnosis: The Role of Liquid Biopsy and CRISPR/Cas Systems in Biomarker Detection

Background/Objectives: Cholangiocarcinoma (CCA) is a highly heterogeneous malignancy of the biliary tract with limited diagnostic tools for early detection. Current serum markers, such as CA19-9, lack specificity and sensitivity, particularly in early-stage disease, which hinders the effectiveness of curative interventions. This narrative review evaluates the limitations of existing diagnostic approaches and explores the potential of combining liquid biopsy (LB) technologies with CRISPR/Cas-based systems for precise, minimally invasive biomarker detection. Methods: A narrative review was conducted, synthesizing literature from 2018 to 2025 across PubMed, MDPI, Web of Science, Google Scholar, and Embase using MeSH terms such as "cholangiocarcinoma," "liquid biopsy," "miRNA," and "CRISPR/Cas." Results: Circulating microRNAs (e.g., miR-21, miR-16, miR-877) exhibit high diagnostic accuracy. The RACE (Rolling Circle Amplification-assisted CRISPR/Cas9 Cleavage) platform shows promise for detecting extracellular vesicle (EV)-derived miRNAs with high sensitivity and single-nucleotide specificity. When paired with liquid biopsy, CRISPR-based assays enable real-time, cost-effective, and multiplexed detection of tumor-specific biomarkers. Conclusions: The introduction of LB combined with CRISPR/Cas systems could potentially revolutionize the early and accurate diagnosis of CCA, thereby advancing the overall treatment strategy. However, this method is still under development and requires further testing before it can be incorporated into routine diagnostics.