Cholangiocarcinoma (ORPHA:70567)
Cholangiocarcinoma (CCA) is a biliary tract cancer (BTC, see this term) originating in the epithelium of the biliary tree, either intra or extra hepatic.
Epidemiology
The prevalence is unknown but it accounts for approximately 3% of gastrointestinal tumors and 10-15% of all hepatobiliary malignancies.
Clinical description
CCA can occur in the intra or extra-hepatic biliary tract. A specific type of extra-hepatic CCA known as a Klatskin tumor (see this term) occurs at the junction where the left and right hepatic bile ducts meet the common bile duct (CBD). It is slightly more prevalent in males than females (1.3:1.0) and usually presents in the fifth to seventh decade of life. Clinical manifestations are not usually noted until an advanced disease stage. Extra-hepatic CCA manifests with signs of cholestasis (jaundice, pale stools, dark urine, pruritus), malaise, weight loss and/or progressive weakness. Intra-hepatic CCA may present with an abdominal mass or with non-specific symptoms of decreased appetite, weight loss, abdominal pain and malaise.
Etiology
The etiology is unknown and most cases of CCA occur sporadically. Risk factors include primary sclerosing cholangitis (see this term), secondary sclerosing cholangitis, chronic typhoid carriage, parasitic infections (Opisthochis viverrini and Clonorchis sinensis), exposure to thorotrast (x-ray contrast medium) and choledochal cysts, all of which cause chronic biliary inflammation.
Diagnostic methods
Diagnosis is suspected on clinical and laboratory findings. Serum carbohydrate antigen (CA) 19-9 is the glycoprotein tumor marker most often used in the diagnosis of CCA. It is found to be elevated in 85% of patients. Increased CEA levels are also noted. Extra-hepatic tumors cause increased levels of alkaline phosphate (ALP), conjugated bilirubin and gamma-glutamyl transpeptidase (GGT) while intra-hepatic have only slightly elevated ALP levels. Abdominal imaging, visualization of the biliary tree and biopsies of the lesion are necessary for diagnosis. Magnetic resonance cholangiopancreatography (MRCP) provides information on intrahepatic metastases, biliary anatomy and tumor extension and is used in the staging of CCA. It has been advocated to replace endoscopic retrograde cholangiopancreatography (ERCP), a more invasive method. Visualization of the biliary tree and samples through brush cytology or bile duct biopsies are obtained with ERCP. A needle biopsy is performed in those with a liver mass. Extra-hepatic CCA is further divided into anatomical subtypes according to the Bismuth classification and a disease stage is given. Ultrasound, and contrast enhanced helical computerized computed tomography (CT) can be used in visualizing the extent of disease.
Differential diagnosis
Intra-hepatic CCA is often mistaken for metastatic adenocarcinoma. Carcinoma of the gallbladder (see this term), benign strictures and Mirizzi syndrome should be excluded.
Management and treatment
Surgical resection is the only potentially curative treatment for CCA but recurrences after surgery are frequent. Unfortunately CCA is often diagnosed as unresectable because of local extension and/or metastases. Distal CCA arising from the CBD is often treated by pancreatoduodenectomy. More proximal CCA needs hepatic resection. Palliative management involves biliary drainage by inserting metal stents in the biliary tree to release the blockage. Adjuvant chemotherapy after surgery or palliative chemotherapy for unresectable CCA is indicated. Gemcitabine combined with cisplatin therapy is the standard treatment for unresectable biliary tract cancers, including CCA.
Prognosis
As proximal CCA is usually not diagnosed until a late stage of disease, prognosis is poor with 5-year survival rates of 20-50% after resection and almost 0% in unresectable tumors. Death is often due to biliary sepsis, cancer cachexia, malnutrition and liver failure.

                            Last update: 
                            September 2012


                            - Expert reviewer(s): 
                            Dr Junji FURUSE