An Exosome-based Liquid Biopsy Signature for Pre-operative Identification of Lymph Node Metastasis in Patients With Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor of the liver arising from epithelial cells of the biliary tract, accounting for 10-15% of primary liver cancers, and the incidence of ICC has increased rapidly worldwide over the past decade. The long-term prognosis is dismal, with a 5-year overall survival (OS) as low as 25-30%. Many studies have highlighted lymph node metastasis as a strong predictor of poor prognosis in ICC patients, prompting efforts such as appropriate lymphadenectomy to accurately predict disease stage and reduce outcomes associated with LNM. Adequate lymphadenectomy in patients with suspected LNM is essential for achieving R0 resection and is a necessary component of complete cure and long-term survival. The routine use of highly invasive lymphadenectomy in all patients remains controversial, and lymphadenectomy rates for ICC range from 26.9% to 100% depending on the literature and are not universally adopted currently.

Currently, LNM is detected preoperatively by imaging, but imaging alone is not sufficient to diagnose LNM, as negative findings by imaging findings may have low sensitivity and may not rule out LNM. Other attempts have been made to develop predictive scoring systems based on Carbohydrate antigen 19-9 (CA 19-9) levels, location of the primary tumor, lymph node patterns on CT and MRI, and other clinical factors to predict LNM in ICC, but all these predictive systems rely heavily on judgment regarding lymph node size and tumor growth patterns are largely left to diagnostic imaging.

This study seeks to validate a panel of more accurate and non-invasive biomarkers (exo-miRNAs) in preoperative blood samples. Accurate preoperative detection of the presence of LNM would help provide clear criteria for ICC treatment decisions, such as the implementation of elective lymphadenectomy or the addition of chemotherapy.