Definition
Cholangiocarcinoma happens when cancer cells grow in the bile duct. The bile duct is made up of a number of branches that carry bile from the liver to the gall bladder and small intestine. Bile is a fluid that helps digest food and eliminate waste from the body.
Bile duct cancers can be divided by their location:
- Intrahepatic—develops in the bile duct branches that are located in the liver
- Perihilar—develops at the point where the branches of the bile duct join and leave the liver (most common form)
- Distal—develops in the area of the bile duct that is closer to the small intestine
Many bile duct cancers arise from glands that line the inside of the bile duct. The term used for this type of cancer is adenocarcinoma.
Causes
The exact cause is unknown. Gene defects may lead to the growth of cancer cells in the bile duct.
Many different gene defects have been found in tumors. p53 gene abnormalities and K-ras gene abnormalities are two common gene defects that have been seen.
Risk Factors
Risk factors include:
- Having a chronic condition that causes inflammation of the bile duct (eg, primary sclerosing cholangitis, ulcerative colitis , bile duct stones, choledochal cysts)
- Having cirrhosis of the liver or another condition that affects the liver or bile duct (eg, polycystic liver disease, Caroli syndrome)
- Being infected by parasites called liver flukes (more common in Asian countries)
- Being older than 65 years
- Being overweight or obese
- Having been exposed to a radioactive substance or toxic chemicals
- Having a family history of bile duct cancer
Other possible risk factors are:
- Smoking
- Having diabetes , hepatitis B or C , or pancreatitis
Symptoms
In the early stages of the cancer, there may not be any symptoms. As the cancer grows, symptoms may include:
- Jaundice (yellowing of the skin and whites of the eyes)
- Abdominal pain
- Fever
- Weakness, fatigue
- Decrease in appetite, weight loss
- Itchy skin
- Dark urine, pale stool
Diagnosis
Your doctor will:
- Ask about your symptoms
- Take your medical history
- Do a physical exam
Tests may include:
- Blood tests to evaluate how the liver and gall bladder are functioning
- Tumor marker tests
- Imaging tests (eg, ultrasound , CT scan , MRI scan , PET scan )
You may also need to have procedures done, such as:
- Endoscopic retrograde cholangiopancreatography (ERCP)—a procedure that involves both x-rays and an endoscope (a long, flexible tube with a camera on one end) to examine the bile duct
- Angiography —an imaging test that uses contrast dye to create x-rays of the blood vessels
- Laparoscopy —a procedure that involves inserting a laparoscope (thin tube with a camera on one end) into the abdominal wall to examine the bile duct
- Biopsy —a procedure that involves removing bile duct cells to examine them under the microscope
Treatment
The treatment plan depends on factors like:
- The stage that the cancer is in (eg, the size and location of the tumor)
- Your overall health
Surgery
Because the bile duct branches into many organs, surgery is very complex. Examples of surgery for different types of cholangiocarcinoma include:
- Intrahepatic bile duct cancer—part of the liver or an entire lobe may be removed
- Perihilar bile duct cancer—part of the liver, bile duct, and gall bladder may be removed
- Distal bile duct cancer—part of the pancreas and small intestine may be removed
If the cancer cannot be removed, other types of surgery may be done to relieve symptoms. For example, a stent (small tube) can be placed inside of a cancerous bile duct to allow bile to flow through it.
Radiation Therapy
Radiation therapy is used to kill cancer cells and shrink tumors. Different forms include:
- External radiation therapy—radiation directed at the tumor from a source outside the body
- Internal radiation therapy—radioactive materials placed into the body in or near the cancer cells
Radiation may be done along with surgery. It may also be the main treatment if cancer cannot be removed.
Chemotherapy
Chemotherapy is the use of drugs to kill cancer cells. This treatment may be used before or after surgery. If the tumor cannot be removed, chemotherapy may be given, either alone or in combination with radiation therapy.
Prevention
You may be able to lower your risk by:
- Maintaining a healthy weight
- Eating a healthy diet and exercising regularly
- Taking precautions to prevent cirrhosis, like getting a hepatitis B vaccine and avoiding or limiting alcohol
- Not smoking
- Avoiding exposure to toxins