General Information About Bile Duct Cancer
Cancer of the bile duct (also called cholangiocarcinoma) is extremely rare. The true incidence of bile duct cancer is unknown, however, because establishing an accurate diagnosis is difficult.
Traditionally, bile duct tumors located within the liver have been classified with hepatocellular carcinoma as primary liver tumors. In contrast, bile duct tumors located outside of the liver have been classified with gallbladder cancer as extrahepatic biliary tract tumors. The classification of bile duct tumors has changed and now includes intrahepatic tumors of the bile ducts and perihilar and distal extrahepatic tumors of the bile ducts.
Approximately 50% of cholangiocarcinomas arise in the bile ducts of the perihilar region; 40% arise in the distal extrahepatic region; and 10% arise in the intrahepatic region.
Many bile duct cancers are multifocal. In most patients, the tumor cannot be completely removed by surgery and is incurable. Palliative measures such as resection, radiation therapy (e.g., brachytherapy or external-beam radiation therapy), or stenting procedures may maintain adequate biliary drainage and allow for improved quality of life.
The biliary system consists of a network of ducts that carry bile from the liver to the small bowel and is classified by its anatomic location (Figure 1). Bile is produced by the liver and is important for fat digestion.
Intrahepatic bile duct
The bile ducts located within the liver are called intrahepatic bile ducts. Tumors of the intrahepatic bile ducts originate in small intrahepatic ductules or large intrahepatic ducts that are proximal to the bifurcation of the right and left hepatic ducts. These tumors are also known as intrahepatic cholangiocarcinomas.
Extrahepatic bile duct
The bile ducts located outside of the liver are called extrahepatic bile ducts. They include part of the right and left hepatic ducts that are outside the liver, the common hepatic duct, and the common bile duct. The extrahepatic bile ducts can be further divided into the perihilar (hilum) region and distal region.
- Perihilar (hilum) region. The hilum is the region where the right and left hepatic ducts exit the liver and join to form the common hepatic duct that is proximal to the origin of the cystic duct. Tumors of this region are also known as perihilar cholangiocarcinomas or Klatskin tumors.
- Distal extrahepatic region. This region includes the common bile duct and inserts into the small intestine. Tumors of this region are also known as extrahepatic cholangiocarcinomas (Figure 2).
Bile duct cancer may occur more frequently in patients with a history of primary sclerosing cholangitis, chronic ulcerative colitis, choledochal cysts, or infections with the liver fluke Clonorchis sinensis.
Distal extrahepatic and perihilar bile duct cancers frequently cause biliary tract obstruction, leading to the following symptoms:
- Weight loss.
- Abdominal pain.
Intrahepatic bile duct cancer may be relatively indolent and difficult to clinically differentiate from metastatic adenocarcinoma deposits in the liver.
Diagnostic and Staging Evaluation
Clinical evaluation is dependent on laboratory and radiographic imaging tests that include the following:
- Liver function tests and other laboratory studies.
- Abdominal ultrasound.
- Computed tomography.
- Magnetic resonance imaging.
- Magnetic resonance cholangiopancreatography.
These tests demonstrate the extent of the primary tumor and help determine the presence or absence of distant metastases.
If a patient is medically fit for surgery and the tumor is amenable to surgical resection, surgical exploration is performed. Pathologic examination of the resected specimen is done to establish definitive pathologic staging.
Prognosis depends in part on the tumor’s anatomic location, which affects its resectability. Because of its nearness to major blood vessels and diffuse extension within the liver, a bile duct tumor can be difficult to resect. Total resection is possible in 25% to 30% of lesions that originate in the distal bile duct; the resectability rate is lower for lesions that occur in more proximal sites.
Complete resection with negative surgical margins offers the only chance of cure for bile duct cancer. For localized, resectable extrahepatic and intrahepatic tumors, the presence of involved lymph nodes and perineural invasion are significant adverse prognostic factors.[4-6]
Additionally, the following have been associated with worse outcomes among patients with intrahepatic cholangiocarcinomas:[7-9]
- A personal history of primary sclerosing cholangitis.
- Elevated cancer antigen 19-9 level.
- Periductal infiltrating tumor growth pattern.
- Presence of hepatic venous invasion.
Other PDQ summaries containing information related to bile duct cancer include the following:
- Siegel R, Ma J, Zou Z, et al.: Cancer statistics, 2014. CA Cancer J Clin 64 (1): 9-29, 2014 Jan-Feb. [PUBMED Abstract]
- de Groen PC, Gores GJ, LaRusso NF, et al.: Biliary tract cancers. N Engl J Med 341 (18): 1368-78, 1999. [PUBMED Abstract]
- Stain SC, Baer HU, Dennison AR, et al.: Current management of hilar cholangiocarcinoma. Surg Gynecol Obstet 175 (6): 579-88, 1992. [PUBMED Abstract]
- Wakai T, Shirai Y, Moroda T, et al.: Impact of ductal resection margin status on long-term survival in patients undergoing resection for extrahepatic cholangiocarcinoma. Cancer 103 (6): 1210-6, 2005. [PUBMED Abstract]
- Klempnauer J, Ridder GJ, von Wasielewski R, et al.: Resectional surgery of hilar cholangiocarcinoma: a multivariate analysis of prognostic factors. J Clin Oncol 15 (3): 947-54, 1997. [PUBMED Abstract]
- Bhuiya MR, Nimura Y, Kamiya J, et al.: Clinicopathologic studies on perineural invasion of bile duct carcinoma. Ann Surg 215 (4): 344-9, 1992. [PUBMED Abstract]
- Rosen CB, Nagorney DM, Wiesner RH, et al.: Cholangiocarcinoma complicating primary sclerosing cholangitis. Ann Surg 213 (1): 21-5, 1991. [PUBMED Abstract]
- Shirabe K, Mano Y, Taketomi A, et al.: Clinicopathological prognostic factors after hepatectomy for patients with mass-forming type intrahepatic cholangiocarcinoma: relevance of the lymphatic invasion index. Ann Surg Oncol 17 (7): 1816-22, 2010. [PUBMED Abstract]
- Isa T, Kusano T, Shimoji H, et al.: Predictive factors for long-term survival in patients with intrahepatic cholangiocarcinoma. Am J Surg 181 (6): 507-11, 2001. [PUBMED