Biliary tract cancer refers to a type of cancer that originates in the bile ducts, which are thin tubes that connect the liver to the small intestine and help transport bile. This type of cancer can occur in various parts of the biliary tract, including the intrahepatic bile ducts within the liver, the common bile duct, and the gallbladder. Biliary tract cancer is relatively rare compared to other types of cancer, and the exact cause is not fully understood. Research in the area of biliary tract cancer focuses on improving early detection methods, developing targeted therapies, and understanding the underlying genetic mutations that contribute to the development of this cancer. Treatment options for biliary tract cancer typically involve surgery, chemotherapy, radiation therapy, and sometimes liver transplantation. Overall, the prognosis for biliary tract cancer can vary depending on the stage of cancer at diagnosis and the effectiveness of treatment.