Bile duct cancer starts in the bile duct. Cancers can develop in any part of the bile duct and, based on their location, are classified into three types:
Intrahepatic Bile Duct Cancers –
- Intrahepatic bile duct cancers
- Perihilar (also called hilar) bile duct cancers
- Distal bile duct cancers
- Cancers in the different areas may cause different symptoms.
These cancers develop in the smaller bile duct branches inside the liver. They can sometimes be confused with cancers that start in the liver cells, which are called hepatocellular carcinomas, and are often treated the same way. Only about 1 in 10 bile duct cancers are intrahepatic.
Perihilar Bile Duct Cancers –
These cancers develop at the hilum, where the hepatic ducts join and consequently leave the liver. They are also called Klatskin tumours. These are the most common type of bile duct cancers, making up 6 or 7 of every 10 bile duct cancers. These cancers are grouped with distal bile duct cancers as extrahepatic bile duct cancers.
Distal bile duct cancers –
These bile duct cancers are found further down the bile duct, closer to the small intestine. Because these bile ducts are outside the liver, the related cancers are grouped with perihilar cancers as extrahepatic bile duct cancers. Distal bile duct cancers make up 2 to 3 of every 10 bile duct cancers.
Signs and symptoms may not be present until the later stages of bile duct cancer, but in some cases they may lead to an early diagnosis. The following are some symptoms associated with bile duct cancer:
- Light-coloured stools
- Dark urine
- Abdominal pain
- Loss of appetite
- Weight loss
- Nausea and vomiting
Bile duct cancer is uncommon. However, certain factors and conditions may put you at greater risk of developing this type of cancer.
Long-standing inflammation is a key risk factor in developing bile duct cancer. Conditions that are associated with this kind of inflammation include:
- Sclerosing cholangitis, which causes inflammation, scarring and sometimes destruction of the bile ducts
- Ulcerative colitis, which causes ulcers in the rectum lining and colon
- Bile duct stones
- Cirrhosis, which is progressive scarring of the liver and is most often caused by alcohol abuse and infections such as hepatitis C and B
Nearly 60% who develop bile duct cancer are over the age of 65.
Liver Fluke Infection
Flukes are parasitic worms that can enter your body if you eat undercooked freshwater fish that contains parasites. Once they have entered the body, liver flukes go and inhabit the bile ducts. The species of fluke connected to bile duct cancer is mostly found in Southeast Asia.
Other Risk Factors
Family history of bile duct cancer, smoking, diabetes and pancreatitis may also play a role.
Bile duct cancer can be a challenging condition to diagnose. If cancer is suspected, the patient is referred to a specialist for tests. Some of the tests are described below:
Blood tests- During bile duct cancer, cancerous cells may release certain chemicals that can be detected using blood tests. These types of proteins are known as tumour markers. However, tumour markers can also be caused by other conditions. A positive blood test does not necessarily mean that the patient is suffering from bile duct cancer, and vice versa.
Scans-The scans performed to diagnose bile duct cancer include:
Endoscopic Retrograde Cholangiopancreatography (ERCP)- During Endoscopic Retrograde Cholangiopancreatography (ERCP), the patient is injected with a special liquid that makes the bile ducts show up more clearly on an x-ray scanner. The x-ray scanner is used to guide an endoscope down the throat and into your bile duct. The endoscope can detect blockages in the bile duct, which could actually indicate bile duct cancer.
Spyglass- An advanced form of ERCP is a special test called a ‘spyglass’. This involves passing a specialised endoscope into the bile duct so that abnormalities if any, can be spotted. It also enables a biopsy to be taken at this stage.
Biopsy- If scans and tests indicate bile duct cancer, a biopsy is carried out to confirm a diagnosis. During a biopsy, a small sample of tissue is taken from the body and checked under a microscope for the presence of cancerous cells. A biopsy is usually performed while ERCP or PTC is being carried out. As well as taking bile and tissue samples from the bile duct, samples may be taken from nearby lymph nodes. This is to check whether the cancer has spread from your bile duct into the lymphatic system.
- Ultrasound scan – high frequency sound waves are used to build up a picture of the inside of your body
- Computer Tomography (CT) scan – a series of x-rays of the liver are taken and a computer is used to assemble them into a more detailed three-dimensional image
- Magnetic Resonance Imaging (MRI) scan – this uses a strong magnetic field and radio waves to produce a picture of the inside of your liver
Most cases of bile duct cancer cannot be cured. Instead, treatment is most commonly used to relieve symptoms. The treatment plan will be determined by the stage the cancer has reached.
In stage 1 and stage 2 cases of bile duct cancer, a cure may be possible by surgically removing the affected part of the bile duct, and possibly some of the liver or gallbladder.
In a stage 3 case, the chances of achieving a successful cure will depend on how many lymph nodes have been affected. A cure may be possible if only a few nodes have cancerous cells in them or it may be possible to slow the spread of the cancer by surgically removing the lymph nodes.
In cases of stage 4 bile duct cancer, achieving a successful cure is highly unlikely. However, chemotherapy, radiotherapy and surgery can often be used to help relieve symptoms.
If it is possible to cure bile duct cancer, surgery will be needed to remove any cancerous tissue. Depending on the extent of the cancer, it may be necessary to remove:
the part of your bile duct that contains cancerous cells,
nearby lymph nodes, and/or
part of your liver.
Unfortunately, due to the aggressive nature of bile duct cancer, fewer than one-third of patients are suitable for surgery. After surgery, it is usually possible to reconstruct what remains of the bile duct so that bile can still flow into the intestine.
Unblocking The Bile Duct:
If the bile duct becomes blocked as a result of cancer, a treatment to unblock the duct is recommended. This will help resolve symptoms such as:
itchy skin, and
abdominal (tummy) pain,
Unblocking the bile duct is sometimes necessary if the flow of bile back into your liver starts to affect the normal functioning of your liver. The bile duct can be unblocked in several ways. The first is to use a variation of the Endoscopic Retrograde Cholangiopancreatography (ERCP) procedure.
During the procedure, a surgeon will guide a long, flexible tube with a light and video camera on the end (endoscope) into the bile duct and pass down a small metal or plastic tube called a stent. The stent is used to widen the bile duct, which should help to get the bile flowing again.
Alternatively, a stent can be placed in the bile duct using a variation of the Percutaneous Transhepatic Cholangiography (PTC) procedure. This involves placing the stent in the bile duct through a small incision in the stomach.
Radiotherapy cannot cure bile duct cancer but can help to relieve the symptoms, slow the spread of cancer and prolong life. Two types of radiotherapy are used to treat bile duct cancer:
External beam radiotherapy – a machine is used to target radioactive beams at your bile duct
Internal radiotherapy (brachytherapy) – a radioactive wire is placed inside your bile duct next to the tumour
Radiotherapy works by damaging cancerous cells. However, it can also damage healthy cells and cause side effects. Side effects of radiotherapy include:
Chemotherapy is used in a way similar to radiotherapy to relieve the symptoms of cancer, slow down the rate at which it spreads and prolong life. It is sometimes used in combination with radiotherapy. As with radiotherapy, medicines used in chemotherapy can sometimes damage healthy tissue as well as cancerous tissue, and adverse side effects are common. Side effects of chemotherapy can include:
However, these side effects should stop once the course of treatment has finished.
Photodynamic Therapy (PDT):
Photodynamic Therapy is a new technique that can help to control – but not cure – the symptoms of bile duct cancer. A special chemical is injected into the bile duct, which makes the cancerous cells more sensitive to light. A laser is then passed through an endoscope and used to shrink the tumour.