Exploring Molecular Mechanisms in the Second-Line Treatment of Biliary Tract Malignant Tumors

Biliary tract malignant tumors account for about 3% of gastrointestinal malignancies. Based on anatomical location, biliary tract malignant tumors can be divided into gallbladder carcinoma, intrahepatic cholangiocarcinoma (ICC), hilar cholangiocarcinoma, and distal cholangiocarcinoma. Surgical treatment is the main treatment for early-stage biliary malignant tumors, the insidious nature of the disease often leads to late diagnoses, causing many patients missing the window for surgical intervention. Gemcitabine combined with cisplatin serves as a first-line treatment for patients with advanced or unresectable lesions, however, a definitive standard for second-line treatment has not yet been established. In recent years, many advances have occurred in the study of the molecular mechanisms contributing to the occurrence and development of biliary malignancies, providing a foundation for targeted treatments of the disease. This review summarizes the existing literature and explores potential second-line treatment options for advanced biliary malignancies based on our understanding of the molecular pathogenesis and tumor pathology.