Bile Duct Cancer (Cholangiocarcinoma)

• Intrahepatic bile duct cancer: Occurs in the liver but is not liver cancer; the least common type of bile duct cancer that accounts for less than 10% of cancers.
• Extrahepatic bile duct cancer: Occurs outside the liver and has two types:
• Perihilar cancer: Occurs at the hilum region, where the right and left bile ducts join to form a hepatic duct
• Distal cancer: Occurs at the portion of the bile duct close to the intestine.
• Gallbladder cancer: Starts in the gallbladder.

Staging is the process of determining whether the bile duct tumors have spread and to what extent. Metastasis occurs through the lymphatic system and blood.

Stages of intrahepatic bile duct cancer

• Stage 0: Abnormal cells are found in the inner layer of the hepatic bile duct.
• Stage I
  • Stage IA: Cancer cells are found in the intrahepatic bile duct, and the tumor is 5 cm or smaller.
  • Stage IB: Cancer cells are found in the intrahepatic bile duct, and the tumor is larger than 5 cm.
• Stage II: One or more tumors are found in the bile duct and have spread into the bloodstream.
• Stage III
  • Stage IIIA: The tumor has spread through the outer lining of the liver.
  • Stage IIIB: The tumor has spread to nearby organs, such as the duodenum, colon, stomach, common bile duct, abdominal wall, and lymph nodes.
• Stage IV: The tumor has spread to distant organs, such as the bones, lungs, or lymph nodes.

Stages of perihilar cancer

• Stage 0: Abnormal cells are found in the tissue lining of the perihilar duct. 
• Stage I: Cancer cells are found in the innermost layer of the bile duct and spread to the muscle layer or fibrous tissue layer of the perihilar duct wall.
• Stage II: Cancer cells have spread through the wall of the bile duct to nearby fatty or liver tissue.
• Stage III
  • Stage IIIA: Cancer has spread to branches of one side of the hepatic artery or portal vein.
  • Stage IIIB: Cancer has spread to one or more of the following:
    • Portal veins or branches on both sides
    • Common hepatic artery
    • Right hepatic duct and left branch of the hepatic artery or portal vein
    • Left hepatic duct and right branch of the hepatic artery or portal vein
  • Stage IIIC: Cancer cells have spread to the nearby 1-3 lymph nodes.
• Stage IV
  • Stage IVA: Cancer has spread to four or more lymph nodes.
  • Stage IVB: Cancer has spread to nearby organs, such as the liver, lung, bone, brain, skin, and distant lymph nodes.

Stage of distal cancer

• Stage 0: Abnormal cells are found in the inner layer of the hepatic bile duct. 
• Stage I: Cancer cells spread about 5 mm into the wall of the distal bile duct.
• Stage II
  • Stage IIA: Cancer has spread about 5 mm into the wall of the distal bile duct, 1-3 nearby lymph nodes, or 5-12 mm into the wall of the distal bile duct.
  • Stage IIB: Cancer has spread more than 5 mm into the wall of the distal bile duct or 1-3 nearby lymph nodes.
• Stage III
  • Stage IIIA: Cancer has spread into the wall of the distal bile duct or 4 nearby lymph nodes.
  • Stage IIIB: Cancer has spread to the large blood vessels that supply to the organs in the abdomen and one or more nearby lymph nodes.
• Stage IV: Cancer has spread to other organs, such as the liver, lungs, or tissue lining, and most of the parts of the abdomen.

The exact cause of bile duct cancer is unclear. Studies have reported that the following facts may increase the risk of bile duct cancer:

• Bile duct abnormalities 
• Bile duct stones or bile duct cysts
• Chronic ulcerative colitis
• Hepatitis B
• Hepatitis C
• HIV
• Inflammatory bowel disease
• Fatty liver disease
• Liver fluke infections
• Primary sclerosing cholangitis
• Obesity
• Diabetes
• Alcohol consumption
• History of smoking

Symptoms of bile duct cancer include:

• Abdominal pain
• Dark-colored urine
• Clay-colored stool
• Jaundice
• Fever
• Fatigue
• Unintended weight loss
• Night sweats
• Itchy skin
• Nausea
• Vomiting

Your healthcare provider will assess your symptoms and perform a physical examination. They may order the following tests to confirm a diagnosis:

• Liver function tests: These detect abnormal levels of liver enzymes, which can indicate bile duct blockage or abnormal liver function.
• Tumor marker tests: These check blood or urine for proteins or other substances that indicate cancer.
• Abdominal ultrasound: Sound waves produce images of structures inside your body, such as the liver, pancreas, and gallbladder.
• Magnetic resonance cholangiopancreatography (MRCP): This uses an MRI machine, to produce detailed images of the liver, pancreas, bile ducts, and pancreatic ducts.
• Endoscopic retrograde cholangiopancreatography (ERCP): This helps detect blockages in the bile duct using an endoscope and catheter which are inserted through the mouth into the small intestine; contrast dye is injected to outline the shape of the bile ducts.
• Percutaneous transhepatic cholangiography: This procedure is used when an ERCP cannot be used. A dye is inserted into the bile ducts and the liver. 

If a tumor is suspected by any of the tests, your healthcare provider may perform a biopsy to confirm the presence of cancer cells.

There are several treatment options for bile duct cancer:

• Bile duct removal: This treatment option involves the surgical removal of the bile ducts if the cancer has not spread to other organs.
• Biliary drainage: If the bile duct is blocked, the doctor may bypass it by cutting and reattaching the bile duct to another side of the duct to allow easy flow.
• Chemotherapy: Chemotherapy can be administered orally or intravenously and uses potent medications to kill cancer cells.
• Radiotherapy: High-power X-rays or other types of radiation are used to kill cancer cells. Radiation therapy may be done before surgery to shrink a tumor or after surgery to kill the remaining cancer cells.
• Liver transplant: Your provider may recommend chemotherapy and radiotherapy before liver transplantation, although this option is although rarely used to treat bile duct cancer.

The overall prognosis for bile duct cancer is poor:

• If the tumor has not spread outside of the bile ducts, the survival rate is only 10%-15%. 
• If the tumor has spread to other organs, such as the lungs, the survival rate is 2% 

Survival rates may improve with newer treatments.