Bile duct cancer (cholangiocarcinoma) happens when abnormal cells grow out of control in the ducts that carry bile between the liver, gall bladder and small intestine. This type of cancer is rarely inherited.
Risk factors for this cancer include hepatitis C infection and heavy drinking. You can reduce your risk by getting a hepatitis C vaccine and using safe needles to inject drugs.
Types
There are several types of cancer that start in the bile ducts. The type depends on where the cancer begins and the kind of cells that are involved.
More than 9 out of 10 bile duct cancers are adenocarcinomas (add-en-oh-KAR-sin-oh-ma). These start in the cells that line the inside of the bile ducts. They usually grow quickly and are hard to treat.
The other cancer that starts in the bile ducts is cholangiocarcinoma (KAH-lan-jih-KOH-roh-koh-mă). This is more common and is more difficult to treat. It usually happens in older people. It often starts in the area where the bile ducts connect with the liver and gallbladder. It may also start in the bile ducts near the small intestine.
Bile ducts are a series of branched tubes that carry bile, a fluid that helps the body digest fats in food. The bile is made in the liver and stored in the gallbladder before it is released into the small intestine after a person eats. Sometimes the bile ducts get blocked by a buildup of fatty substances or by scar tissue. This can cause jaundice (yellowing of the skin and whites of the eyes).
Several kinds of cancer start in the lining of the innermost layer of the intrahepatic bile duct. These are called stage 0 intrahepatic bile duct cancer or cholangiocarcinoma in situ. They may not be cancer but can become cancer later.
There are other types of bile duct cancer that begin in other places in the liver or in bile ducts outside the liver. These are called extrahepatic cholangiocarcinoma.
To diagnose bile duct cancer, your doctor will do a physical exam and ask about your past health. You will have a blood test to check your liver function and your levels of the enzymes alkaline phosphatase and bilirubin. Your doctor may also order a tumor marker test to see if you have bile duct cancer. The tumor marker test measures the amount of a substance called carbohydrate antigen 19-9 in your blood. Bile duct cancer cells make this substance at higher rates than normal.
Symptoms
The most common symptom is jaundice, which causes the skin and whites of the eyes to look yellow. This happens because the bile can’t flow properly through the liver and into the bloodstream, so it backs up in the liver and digestive tract.
Other symptoms may include itching (skin itching), fever, tiredness and loss of appetite. If you have these symptoms, it’s important to see your doctor as soon as possible.
Your doctor will do a physical exam and take your medical history. They’ll also order blood tests to check your liver function and the levels of substances such as bilirubin and liver enzymes. They may also order a special type of imaging test called magnetic resonance cholangiopancreatography (MRCP) or endoscopic retrograde cholangiopancreatography (ERCP), which gives doctors detailed images of your liver, gallbladder and bile ducts. These images can help your doctor find the cause of your symptoms.
These tests can help your doctor decide which treatment is best for you. They can also show how far the cancer has spread, which is called staging. Staging helps your doctor plan your treatment and predict how well you might recover.
The main staging system for bile duct cancer is the TNM system, which stands for tumor, node and metastasis. It tells your doctor how big the cancer is and whether it has spread to nearby organs and tissues.
To stage a bile duct cancer, your doctor will look at the size of the tumor and how it is growing. They will also look at how the cancer is growing in other places in your body, such as the lymph nodes and liver.
Your doctor will give you a number that describes how serious your cancer is, based on how the cells look under a microscope. Your doctor will also use a system called the Bismuth-Corlette system to describe how your cancer is likely to respond to treatment. This is especially important for predicting how you might feel after your surgery. This information is also used to decide which chemotherapy drugs you might need.
Diagnosis
The liver, gallbladder and bile ducts are connected by thin tubes (ducts). Cancers that start in the bile ducts can develop in the part outside the liver (extrahepatic) or inside the liver (intrahepatic).
Your doctor will diagnose bile duct cancer by looking at your symptoms and doing tests. The main tests are imaging scans – for example, an X-ray, CT or MRI scan. These can show a blocked or narrowed duct or a tumour. Your doctor may also do a procedure called a cholangiogram to check your bile ducts for blockages. This involves injecting a dye into your ducts and taking pictures of them with an X-ray machine.
You might have a special type of MRI called magnetic resonance cholangiopancreatography (MRCP) to look at your bile ducts in more detail. You might also have a procedure called endoscopic retrograde cholangiopancreatography (ERCP). This is where your doctor inserts a tube with a camera and light at the tip into your bile ducts to see any blockages or tumours. They might also insert a stent to treat the tumour or blockage.
These procedures can often be done under local anaesthetic. Your doctor might also inject a drug to make you drowsy (sedation) before you have the ERCP. You might have another test called a cholangioscopy during an ERCP. This is where your doctor inserts a smaller tube with a probe and camera at the tip into your bile sphincter. They might take a sample of tissue from the bile duct or the tumour.
Blood tests might also help your doctor find out how big your bile duct cancer is and whether it has spread. These include measuring the level of a protein called carbohydrate antigen 19-9, which is overproduced by some cancers including bile duct cancer.
Other blood tests might be used to assess how your liver is working, or to check if you have other conditions such as pancreatitis. You might also have a biopsy of your bile duct or other parts of your body. A specialised microscope checks the cells for signs of cancer. The test can also tell how abnormal the cancer cells are, which is important for deciding what treatment you might need.
Treatment
If the cancer is found early, it is often possible to treat it completely with surgery or other procedures. You may also need to have chemotherapy or immunotherapy to control the cancer and relieve symptoms. This is a combination of drugs that targets cancer cells and boosts your body’s own immune system. Your doctor will choose which type of treatment to use based on your needs and how the cancer is staged. Staging describes how big the cancer is and whether it has spread. Your doctor will base this on how abnormal the cancer cells look under a microscope and what parts of the body the cancer has affected (the T, N, and M stages).
A small number of bile duct cancers develop in the ducts inside the liver (intrahepatic). Most cholangiocarcinomas, however, develop in the larger ducts that run from the liver to the small intestine (extrahepatic).
Your doctor will examine you and take a sample of the tumor using a thin needle inserted through the skin into the area of concern. He or she will often need to perform this procedure using imaging tests, such as an endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP).
The biopsy is then sent to a laboratory for further testing. Your doctor will then grade the cancer based on how the cells look under a microscope. This information helps to predict how fast the cancer might grow and whether it is likely to spread.
In the UK, a biopsy of your bile duct cancer is usually sent to a specialist unit for further examination. This multidisciplinary team is made up of doctors, nurses, physiotherapists, occupational therapists, dietitians, psychologists and other health professionals. They follow National Comprehensive Cancer Network guidelines when developing a treatment plan for you.
If the cancer is in your bile duct and has not spread, your doctor may recommend that you have chemotherapy or immunotherapy. Your doctor will also suggest other treatments to control your symptoms, such as having a tube (stent) put in to relieve a blockage or taking painkillers. If the bile duct cancer has spread, you will need to see a specialist called a medical oncologist.
