Understanding Bile Duct Cancer: The Essentials

Overview

Cholangiocarcinoma is a cancer that forms in the bile ducts. As the name suggests, these ducts carry bile, a fluid that helps break down fat for digestion. Bile is made in the liver and stored in the gallbladder, a tiny pear-shaped pouch that sits just under the liver. The bile ducts are a network of tubes that connect the gallbladder and liver to the small intestine. There are three main ducts involved in this system:¹

• Common hepatic duct - this is formed by the joining of the left and right hepatic ducts, transporting bile outside of the liver
• Cystic duct - the duct connected to the gallbladder, allowing bile to be stored inside the gallbladder. Once fat containing food reaches the small intestine, it carries bile from the gallbladder
• Common bile duct - the cystic duct and the common hepatic duct combine to form the common bile duct. This duct passes behind the pancreas and joins the small intestine

Cholangiocarcinoma can form anywhere within this biliary tree, and its treatment and prognosis can vary according to its site. The three types of biliary duct cancers are:^1,2

• Intrahepatic cholangiocarcinoma - where the tumour starts within the liver
• Perihilar/ hilar cholangiocarcinoma - where the tumour starts at the hilum, the area just outside the liver
• Distal cholangiocarcinoma - where tumour starts further down the bile duct

Causes of cholangiocarcinoma

Most causes of cholangiocarcinoma are sporadic and have no identifiable cause. However, certain specific risk factors have been identified, including:³

• Chronic liver disease - such as liver cirrhosis and chronic hepatitis
• Gallstones
• Inflammation of the gallbladder (cholecystitis)
• Primary sclerosing cholangitis - a chronic disease where the bile ducts inside and outside of the liver become scarred and inflamed. This disorder is highly linked to developing biliary cancer, with nearly 30% of all cholangiocarcinomas being diagnosed in these patients
• Genetic disorders - cystic fibrosis, Lynch syndrome
• Infections- liver flukes, HIV (Human Immunodeficiency Virus), and Helicobacter pylori
• Diabetes, obesity, metabolic syndrome

Signs and symptoms of cholangiocarcinoma

General symptoms of biliary cancer are:^4,5

• Jaundice - yellowing of the skin and whites of your eyes
• Itching
• Dark urine
• Pale faces
• Losing appetite
• Losing weight without a known cause
• Feeling unwell, or tired
• Abdominal pain, particularly on the right side of the abdomen below your ribs
• High temperature, shivering

However, symptoms and when they present can vary depending on the location of the tumour. Extrahepatic (perihilar and distal) cholangiocarcinomas often present with symptoms earlier than intrahepatic cholangiocarcinomas, as these tumours are more likely to compress the bile duct and other surrounding organs. Intrahepatic bile duct cancer tends to not present with symptoms until they are very large, and are less likely to present with jaundice.³

Management and treatment for cholangiocarcinoma

There are several medical and surgical options to help treat cholangiocarcinoma, depending on the size and spread of the cancer. Surgery is an option that can completely cure biliary tract cancer, however, its effectiveness depends on how deep the tumour has spread, and whether it has involved any other surrounding structures. Surgery, therefore, is not an option for everyone. 

For patients with advanced biliary tract cancer, treatment is more aimed at reducing the size of the tumour and prolonging a good quality life. The placement of a stent, a small tube that helps keep the bile duct open to allow the bile to flow through, can help reduce symptoms such as jaundice. Other options include: 

• Chemotherapy is the use of medication to kill cancer cells. It can be given either before surgery (neoadjuvant) or after (adjuvant)
• Radiotherapy (usually external radiotherapy)
• Targeted cancer drugs (Pemigatinib)
• Photodynamic therapy (using light to kill cancer cells)

FAQs

How is cholangiocarcinoma diagnosed

The following tests may be required to confirm the diagnosis of cholangiocarcinoma, to find out the size and the spread, and to stage the cancer to decide the most suitable treatement options.^6,7

• Blood tests - blood samples are examined to check liver function and the certain markers that may indicate the presence of cancer
• Scans - can be used to detect the presence and help stage biliary tract cancer. Specifically, they include:
  • Ultrasound scan for bile duct cancer
  • Endoscopic ultrasound scan (EUS)
  • CT scan (Computerised tomography)
  • MRI (magnetic resonance imaging) and MRCP (magnetic resonance cholangio pancreatography) scan
• Biopsy - a collection of a small sample of cells is taken and then examined under the microscope
• ERCP - Endoscopic retrograde cholangiopancreatography - a procedure that combines endoscopy and x-rays to treat problems of the pancreatic and bile ducts
• PTC - percutaneous transhepatic cholangiography - a procedure where a needle is inserted through the skin and liver to the bile ducts. Dye is injected and then an x-ray is used to examine the blocked area

How can I prevent cholangiocarcinoma

Unfortunately, there is no proven way to prevent biliary tract cancer as many of the known risk factors for bile duct cancer such as age and bile duct abnormalities cannot be changed. However, there are things you can to do help prevent cholangiocarcinoma and other types of cancer.⁸

• Reducing alcohol intake - alcohol abuse can lead to inflammation and cirrhosis, a risk factor for biliary cancer
• Regular exercise
• Eating a healthy diet - including fruits, vegetables, and whole grains, alongside reducing red meats, highly processed foods, and sugary drinks
• Stopping smoking
• Be careful when travelling - liver flukes are more common in certain parts of the worldDrinking purified water and eating well-cooked food can reduce this risk

Who are at risk of cholangiocarcinoma

Biliary cancer can affect anyone, but some groups of people are more at risk. These include:⁹

• People over the age of 60 - this is the age group where cholangiocarcinoma is most diagnosed
• Tobacco smokers
• People with a family history of cholangiocarcinoma
• People with a high BMI (body mass index)

How common is cholangiocarcinoma

Cholangiocarcinoma is a rarer type of cancer that makes up approximately 3% of all cancers of the digestive system.¹⁰ In the UK, around 1,000 new cases are diagnosed yearly.¹¹

What are the stages of cholangiocarcinoma

The staging of cancer helps describe the amount of cancer in the body, its severity, and the best approach to treating it. Staging is often determined by imaging and is based on the size, position, and spread of the tumour. For cholangiocarcinoma, there are three separate staging systems depending on the location of the tumour.²

Intrahepatic cholangiocarcinoma

Perihilar/ Hilar cholangiocarcinoma

Distal cholangiocarcinoma

When should I see a doctor

It is recommended to see a doctor if you have any of the following symptoms:⁵

• Tiredness, or feeling unwell
• Abdominal pain
• Jaundice
• Dark urine
• Pale stools
• Itching of the skin

If you have suddenly lost weight without trying to, it is also advisable to contact your healthcare provider, as this could be a sign of cancer.

Summary

Cholangiocarcinoma is a cancer that can form anywhere within our biliary system. It is usually a type of cancer that is diagnosed later, but fortunately, it is rare and its main specific risk factors affect only a selected group of individuals. If you experience any symptoms that concern you, it is always best to consult a healthcare provider.