Bile Duct Cancer

Bile duct cancer is a rare but aggressive form of cancer that develops in the thin tubes connecting your liver, gallbladder, and small intestine. Often diagnosed at advanced stages when treatment is challenging, this disease requires specialized care and a comprehensive understanding of available options.

Table of contents

• What is bile duct cancer?
• Other names
• Associated anatomy
• Types of bile duct cancer
• Signs and symptoms
• Risk factors
• Diagnosis
• Treatment options
• Outlook

What is bile duct cancer?

Bile duct cancer is a rare disease in which cancer cells form in the bile ducts^[1]. Bile ducts are a network of thin tubes that connect your liver, gallbladder, and small intestine. These tubes carry a fluid called bile, which is made by the liver and stored in the gallbladder. Bile helps your body break down fats during digestion^[2].

This type of cancer is aggressive, which means it spreads quickly. Most people receive a diagnosis after the cancer has already spread outside their bile ducts, at which point it becomes difficult to treat^[3]. About 8,000 people in the United States develop bile duct cancer each year^[3].

Bile duct cancer occurs mostly in people older than age 50, though it can occur at any age. It is most common in people around age 70^[1][3].

Other names

cholangiocarcinoma, bile duct malignancy

Associated anatomy

• Liver
• Bile ducts
• Gallbladder
• Small intestine

Types of bile duct cancer

Doctors divide bile duct cancer into different types based on where the cancer occurs in the bile ducts. There are two main categories: cancers inside the liver and cancers outside the liver^[2].

Intrahepatic bile duct cancer forms in the bile ducts inside the liver. Only a small number of bile duct cancers are intrahepatic, accounting for about 10% of cases. This type is sometimes classified as a type of primary liver cancer^[1][8].

Extrahepatic bile duct cancer forms in the bile ducts outside the liver. This category is further divided into two types^[2]:

• Perihilar bile duct cancer (also called hilar cholangiocarcinoma or Klatskin tumor) is found in the area where the right and left bile ducts exit the liver and join to form the common hepatic duct. This is the most common form of bile duct cancer, representing approximately 50% of cases^[1][3][8].
• Distal bile duct cancer is found in the portion of the bile duct nearest the small intestine. The common bile duct passes through the pancreas and ends in the small intestine. This type accounts for about 40% of cases^[1][8].

Signs and symptoms

Bile duct cancer often does not cause symptoms until it reaches advanced stages. Symptoms typically start when the cancer is large or has spread. Cholangiocarcinoma is not usually painful in the early stages^[2][3].

Common signs and symptoms include^[2][3]:

• Jaundice (yellowing of the skin and whites of the eyes)
• Dark urine
• Clay-colored or greasy stools
• Itchy skin
• Abdominal pain, particularly in the right upper part of the abdomen underneath the ribs
• Fever
• Fatigue
• Nausea and vomiting
• Unexplained weight loss and loss of appetite

Many of these symptoms may be caused by other health problems. However, it is important to see a doctor if you experience these symptoms. Only a doctor can determine if you have cancer^[2].

There are no routine screening tests to check for bile duct cancer before signs and symptoms occur^[2].

Risk factors

Experts do not know exactly what causes bile duct cancer. However, health conditions that cause long-term inflammation in the bile ducts may play a role. Ongoing damage from inflammation can cause changes in cell DNA, which contains the instructions that tell cells how to behave. Damaged DNA can cause problems with how cells grow and divide, creating tumors that damage tissue^[3].

Several factors may increase the risk of developing bile duct cancer^[3][4]:

• Age: The risk increases with age, particularly in individuals over 65
• Gender: Women are more prone to gallbladder cancer, while bile duct cancer affects both men and women equally
• Primary sclerosing cholangitis (PSC), a condition that causes inflammation and scarring of the bile ducts
• Chronic inflammation of the bile ducts or gallbladder
• Gallstones, especially larger ones
• Bile duct cysts
• Abnormal bile ducts that allow bile to flow the wrong way
• Cirrhosis (scarring of the liver)
• Chronic ulcerative colitis and inflammatory bowel disease
• Infection with hepatitis B or C
• Liver fluke infection (particularly common in Southeast Asia)
• Being overweight or obese
• Diabetes (type 1 or type 2)
• Nonalcoholic fatty liver disease
• Exposure to certain chemicals used in rubber and automobile plants
• Alcohol use

Worldwide, bile duct cancer is more common in Southeast Asia, where it is a complication of chronic infection with a liver fluke parasite^[3].

Diagnosis

If your doctor suspects bile duct cancer, you may undergo one or more tests. Diagnosis involves a combination of medical history review, physical examination, and diagnostic tests^[9].

Blood tests can help evaluate your condition. Liver function tests measure how well your liver is working and can give your doctor clues about what is causing your symptoms. A tumor marker test checks the level of carbohydrate antigen (CA) 19-9 in your blood. CA 19-9 is a protein that is overproduced by bile duct cancer cells. However, a high level does not necessarily mean you have cancer, as this result can also occur in other bile duct diseases^[9].

Imaging tests help visualize the organs and detect abnormalities. These may include^[9]:

• Abdominal ultrasound
• Computed tomography (CT) scans
• Magnetic resonance imaging (MRI)
• Positron emission tomography (PET) scans

Endoscopic retrograde cholangiopancreatography (ERCP) uses a dye to highlight the bile ducts on X-ray images. A thin, flexible tube with a camera on the end, called an endoscope, goes through the throat and into the small intestine. The dye enters the ducts through a small tube passed through the endoscope. This test allows doctors to examine the bile ducts closely^[9].

Endoscopic ultrasound involves inserting a long, flexible tube down your throat and into your abdomen. An ultrasound device at the end of the tube emits sound waves that generate images of nearby tissues^[9].

A biopsy involves removing a small sample of tissue to examine under a microscope. This is the only way to confirm the presence of cancer cells. Biopsy results help doctors plan the best treatment for you^[9].

Treatment options

Treatment for bile duct cancer depends on whether the cancer can be completely removed with surgery (resectable) or not (unresectable). Your care plan may include several different approaches^[10].

Surgery is the main treatment when bile duct cancer is found early and has not spread. About a third of patients with bile duct cancer are treated with surgery to remove the tumor. Several types of surgical procedures may be used^[10][11]:

• Removal of the bile duct if the tumor is small and confined to the duct
• Partial hepatectomy, which removes the part of the liver where cancer is found along with some normal tissue around it
• Whipple procedure, which removes the head of the pancreas, the gallbladder, part of the stomach, part of the small intestine, and the bile duct

If the cancer cannot be removed, doctors may perform surgery to help control symptoms. Biliary bypass creates a new pathway around a blocked area. Stent placement involves putting in a thin, flexible tube to drain bile that has built up. These procedures can help relieve jaundice and improve quality of life^[10].

Chemotherapy uses medicines to kill cancer cells or keep them from growing. You may have chemotherapy after surgery to get rid of any remaining cancer, or to help make the cancer smaller and control symptoms if you cannot have surgery. The most commonly used chemotherapy combination for bile duct cancer is gemcitabine and cisplatin^[10][7].

Radiation therapy uses high-energy X-rays or other types of radiation to kill cancer cells. It may be used after surgery to help stop the cancer from coming back, or to help control and improve symptoms of advanced cancer. Radiation therapy can be given from outside the body (external beam radiation) or from inside the body near the cancer (brachytherapy)^[10].

Targeted therapy and immunotherapy are newer treatment approaches. Targeted medicines kill cancer cells by focusing on specific characteristics of the cells. Immunotherapy uses medicines to help your immune system kill cancer. These treatments may be used on their own or with chemotherapy, particularly if the cancer has spread to other parts of the body^[13].

After doctors remove all the cancer that can be seen during surgery, some people may receive chemotherapy or radiation therapy to kill any cancer cells that are left. Treatment given after surgery to lower the risk that cancer will come back is called adjuvant therapy^[10].

Outlook

Bile duct cancer is often diagnosed when it is advanced, making successful treatment difficult to achieve. The outlook depends on many factors, including whether the cancer is inside or outside the liver and the stage at which it is diagnosed^[1][4].

If you have advanced bile duct cancer that has spread beyond the bile ducts into nearby lymph nodes or organs, or to parts of the body further away, it is unlikely to be cured. However, treatment can help slow the cancer’s growth and relieve symptoms^[4][13].

Experts are continually researching and developing new treatments that can slow cancer spread and improve the outlook for people with bile duct cancer. Clinical trials are ongoing to test new therapies^[3].

If the cancer cannot be cured, the aim of treatment is to limit the cancer and its symptoms and help you live longer. You will be referred to a special team of doctors and nurses called the palliative care team or symptom control team. They work with you to help manage your symptoms and make you feel more comfortable^[13].