Cholangiocarcinoma, also known as bile duct cancer or biliary tract cancer, is a rare type of cancer that develops in the bile ducts of the body. The bile ducts are a group of thin tubes that carry bile (a digestive fluid) from the liver and gallbladder to the intestines.
The liver is an organ that sits under the ribs on the upper right side of the abdomen. It is a component of the digestive system, and has many important functions such as producing bile to dissolve fat and digest food. The bile produced by the liver is sent to the gallbladder (a small, pear-shaped organ located under the liver) to be stored. The liver has two bile ducts, known as the left and right hepatic ducts, which join together outside of the liver to form the common hepatic duct. The cystic duct from the gallbladder joins the common hepatic duct to form the common bile duct. Cancer can develop in any of these bile ducts. In most cases, cholangiocarcinoma occurs as a type of carcinomacancer arising from tissues that line organs.
Cholangiocarcinoma is slightly more common in males, and tends to be diagnosed in people over 70. However, anyone can develop this disease.
Types of Cholangiocarcinoma
There are three primary types of cholangiocarcinoma, which are categorised by the area they develop in.
Intrahepatic Cholangiocarcinoma
Intrahepatic cholangiocarcinoma is a cancer that develops in any of the bile ducts within the liver. These types of cancers may be confused with hepatocellular carcinomas of the liver, and are often treated in the same way. Unfortunately, these cancers are often aggressive.
Hilar Cholangiocarcinoma
Hilar cholangiocarcinoma, also known as perihilar cholangiocarcinoma or Klatskin tumour, is the most common type of cholangiocarcinoma. It is a cancer that develops at the junction of the right and left hepatic bile ducts in an area known as the hilum. Unfortunately, these cancers are often aggressive.
Extrahepatic Cholangiocarcinoma
Extrahepatic cholangiocarcinoma is a cancer that develops in a bile duct outside of the liver. This generally occurs in the common bile duct, and often close to the small intestine. Unfortunately, these cancers are often aggressive.
Treatment
If a cholangiocarcinoma is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (node) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, age, stage of disease and overall health.
Treatment for cholangiocarcinomas may include:
- Surgery, potentially including:
- Hepatectomycomplete or partial removal of the liver.
- Hepatic lobectomya surgical procedure where a lobe of an organ (e.g. the lung) is removed (removal of a lobe of the liver).
- Pancreaticoduodenectomyremoval of part of the pancreas (generally the head), the first part of the small intestine (duodenum), part of the stomach, the gallbladder, and part of the common bile duct; also known as a Whipple procedure, also known as a Whipple procedureremoval of part of the pancreas (generally the head), the first part of the small intestine (duodenum), part of the stomach, the gallbladder, and part of the common bile duct; also known as a pancreaticoduodenectomy.
- Cholecystectomyremoval of the gallbladder.
- Stent placementinsertion of a thin wire into a vessel (such as an artery) to help keep it open and prevent narrowing or blockage.
- Organ transplant (liver).
- Lymphadenectomysurgical removal of lymph node(s).
- Portal vein embolisationa procedure used to selectively block blood flow to a section of the liver, which is usually done prior to surgical removal of liver tumours.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
While the cause of cholangiocarcinomas remain unknown, the following factors may increase the likelihood of developing the disease:
- Long term inflammation of the bile ducts, potentially caused by:
- Infection with the virus Hepatitis B or C.
- Fatty liver disease.
- Chronic liver disease.
- Inflammatory bowel diseases, potentially including:
- Crohn’s disease.
- Ulcerative colitis.
- Infection with the liver fluke parasite.
- Bile duct stones.
- Liver cirrhosis.
- Certain inherited conditions, such as:
- Choledochal cystsabnormal growths that are usually filled with liquid or air.
- Cystic fibrosis.
- Lynch syndrome.
- Having a history of smoking.
- Excessive alcohol intake.
- Diabetes (types 1 &2).
- Exposure to certain chemicals (especially in the printing industry).
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
Early-stage cholangiocarcinomas may appear asymptomatic. As the cancer progresses, some of the following symptoms may appear:
- Jaundiceyellowing of the skin and the whites of the eyes caused by an increase of bile in the blood.
- Itchy skin.
- Abdominal pain, discomfort and/or swelling.
- Fatigue.
- Unexplained weight loss/loss of appetite.
- Nausea and vomiting.
- Dark urine.
- Pale or clay coloured stool.
- Fevers and chills.
- A hard and potentially painful lump on the upper right side of the abdomen.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have a cholangiocarcinoma, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Imaging tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Laparoscopya minimally invasive surgical procedure that uses small incisions to access the body for procedures, also known as keyhole surgery.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
