Bile Duct Cancer: A Guide to This Rare But Aggressive Cancer
This article explains bile duct cancer, including its symptoms, causes, diagnosis, and treatment.
The bile duct system starts in the liver with small ductules that collect bile. These tiny tubes join to form larger ducts and exit the liver in one common hepatic duct. This duct joins a duct from the gallbladder, where the body stores extra bile for later use. They form the common bile duct that takes bile to the small intestine.
There are three types of bile duct cancer depending on where in the system cancer occurs:
- Distal bile duct cancer: This cancer starts outside the liver, close to the small intestine. It is the most common form of bile duct cancer.
- Hilar or perihilar bile duct cancer: This cancer, commonly known as a Klatskin tumor, starts where the hepatic ducts join outside the liver.
- Intrahepatic bile duct cancer: This cancer starts in the small ducts inside the liver. This cancer accounts for 10–20% of cases that start in the liver.
Distal bile duct cancer and hilar or perihilar bile duct cancer are grouped under extrahepatic bile duct cancers, which begin outside the liver.
Doctors use the TNM (tumor, nodes, metastasis) staging system for most cancers. They stage cancer using the Roman numerals I-IV. This system is complex for stages of bile duct cancers and differs for each type. Doctors still use it, but they usually discuss treatment using a simpler method.
To plan treatment, doctors classify bile duct cancers into two categories:
- Resectable: Doctors should be able to completely remove the bile duct cancer with surgery.
- Unresectable: This means cancer has spread too far for surgery to be successful.
Doctors will determine whether a cancer is resectable or not by looking at its spread:
- Local: The cancer is only within the bile duct and is usually resectable.
- Locally advanced: The cancer is in nearby tissues but has not spread widely and may be resectable.
- Metastatic: The cancer is widespread and is likely unresectable.
- Recurrent: Cancer has come back after treatment and is likely unresectable.
Generally, bile duct cancer stages 0, I, and II are resectable. Most stage III and IV cancers are not.
When symptoms occur, they are usually due to a blocked bile duct. Symptoms can include:
- abdominal pain
- dark urine
- jaundice, which is yellowing of the skin or eyes
- light- or clay-colored stools that may be greasy
- loss of appetite
- unintended weight loss
Contact your doctor if you develop any of these symptoms.
Cancer starts at the cellular level with genes. Changes in DNA cause problems with the processes that control cell growth. The result is cells that look and grow abnormally. While scientists understand this part, they do not know exactly what triggers these changes.
Sometimes, the changes, or mutations, that cause cancer are hereditary. People inherit them from a parent. However, most of the time, people acquire cancerous mutations during their lifetime. This is the case with bile duct cancer.
Most bile duct cancers show changes in the gene TP53. Other genes that may play a role include:
Risk factors are things that doctors have linked to the chances of getting a disease. Having a risk factor does not necessarily mean you will get the disease. Likewise, you may get the disease without having any risk factors.
Some risk factors are under your control, and some are not.
Risk factors for bile duct cancer include:
- alcohol use
- diseases of the liver or bile ducts, such as liver cirrhosis, hepatitis B or C, nonalcoholic fatty liver disease, and bile duct stones
- exposure to certain chemicals, such as dioxin, nitrosamines, and polychlorinated biphenyls
- family history of bile duct cancer
- inflammatory bowel disease
- older age
Disease prevention mainly relies on changing risk factors that are under your control. With bile duct cancer, it is not possible to prevent most of them. However, you can take steps to keep yourself and your liver healthy. This may help reduce the risk of bile duct cancer.
Healthy lifestyle habits include:
- avoiding or limiting alcohol use
- exercising regularly
- following safety guidelines when working with chemicals
- getting the hepatitis B vaccine
- maintaining a target body weight
- protecting yourself against foodborne and sexually transmitted diseases, including hepatitis B and C
- treating hepatitis infections if they occur
Talk with your doctor about your risk of bile duct cancer and ways you can stay healthy.
To diagnose bile duct cancer, doctors will take a medical history and perform an exam. Testing may include:
- Blood tests: These include liver function tests and tumor markers.
- Imaging exams: Options include ultrasound, CT scan, and MRI scan.
Specialized imaging tests are also available to closely examine the blood vessels and bile ducts, including:
- Hepatic angiography: This is a catheter-based X-ray to study of blood vessels of the liver.
- Cholangiography: This X-ray with contrast helps visualize obstructions in bile ducts. Examples include endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC).
The only way to know for certain if a tumor is cancerous is to take a biopsy. Doctors usually do not do this ahead of surgery for bile duct cancer. They typically proceed to surgery if they suspect cancer and send the tissue for analysis.
Treatment of bile duct cancer depends on whether it is resectable.
Resectable bile duct cancer treatment
The main treatment for resectable or localized bile duct cancer is surgery. Surgery may involve bile duct removal or partial hepatectomy (removal of the liver) for intrahepatic and hilar bile duct cancers. For distal bile duct cancers, doctors may perform a Whipple procedure.
After surgery, doctors may recommend chemotherapy or external radiation therapy. This adjuvant therapy may help reduce the risk of cancer returning.
If cancer is borderline resectable, doctors may use chemotherapy or radiation therapy to try to shrink it. This neoadjuvant therapy may reduce the size enough to make it fully resectable.
Unresectable bile duct cancer treatment
Surgery may still be part of the unresectable bile duct cancer treatment plan. However, the goal is to relieve symptoms, not eliminate the cancer.
Other treatment options may include:
One of the main complications of bile duct cancer is recurrence. There is a very high recurrence rate with this cancer. About 50% of resectable bile duct cancers will eventually return.
Other complications can develop from bile duct cancer treatments.
Here are some questions people often ask about bile duct cancer.
How fast does bile duct cancer spread?
Bile duct cancer is an aggressive cancer. In most cases, it has already spread beyond the bile ducts at diagnosis. Doctors may find a small number of them early when surgery can still remove the cancer.
What happens in the final stages of bile duct cancer?
In the final stages of bile duct cancer, treatment becomes palliative. The focus is on reducing symptoms and improving quality of life as much as possible.
What is the survival rate of bile duct cancer?
The survival depends on the stage at diagnosis and the specific subtype. Localized intrahepatic bile duct cancer has a higher survival rate than extrahepatic bile duct cancer or more advanced disease.
The overall 5-year relative survival rate is about 30%. People with bile duct cancer may consider participating in a clinical trial to advance treatment research.
Bile duct cancer is usually advanced at the time of diagnosis. Most people do not have symptoms until the cancer is in later stages. For a small number of people, surgery may be able to remove all the cancer. However, the recurrence rate is still high.