Bile Duct Cancer (Cholangiocarcinoma) Diagnosis and Staging

November 22, 2024

This page was reviewed under our medical and editorial policy by Laleh Melstrom, M.D., M.S., associate professor of surgery and immuno-oncology, Division of Surgical Oncology, Department of Surgery, City of Hope^® Cancer Center Duarte

The bile ducts are located deep within the body, making it difficult to detect early-stage tumors during a standard physical. Without a standard screening test, bile duct cancer tends to be diagnosed and treated at more advanced stages when the cancer has grown and spread.

How Is Bile Duct Cancer Detected and Diagnosed?

To diagnose bile duct cancer, doctors first assess a patient’s personal and family health histories, in addition to their risk factors and symptoms.

Patients also undergo a physical exam and one or more of the tests listed below.

Biopsy: To conduct a biopsy, a small piece of the bile duct is removed and analyzed by a pathologist to determine if cancer is present.

Several types of biopsy procedures may be considered, based on the patient’s overall health and whether he or she is in a strong physical and emotional state to cope with surgery and manage recovery at that time.

Blood tests: Liver function tests and liver enzyme tests may help identify bile duct blockages. Liver enzyme tests are also used to recognize inflammation and irritation of the liver.

Additional blood tests may be done to detect elevated levels of certain substances known as tumor markers. Two tumor markers are associated with bile duct cancer: carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9, as detailed below.

Carcinoembryonic antigen (CEA): This protein is normally found in very low levels in adults. Bile duct cancers and other cancer types may cause elevated CEA levels, so testing may indicate that cancer is present.

However, elevated CEA levels may also stem from other health conditions. CEA testing is used after diagnosis to help doctors learn more and also to monitor treatment and look for cancer recurrence. 

Cancer antigen (CA 19-9): Another type of protein normally found in low levels in adults, high levels of CA 19-9 may indicate the presence of cancer. CA 19-9 testing is used for diagnosis, monitoring treatment and looking for cancer recurrence.

Imaging Tests for Bile Duct Cancer

Abdominal ultrasound: The initial imaging test a patient undergoes is usually an ultrasound. This type of test uses sound waves to create images of potential bile duct cancer tumors. Abdominal ultrasounds require no radiation and are noninvasive.

A doctor or ultrasound technician simply moves a wand-like instrument over the abdomen to capture the echoes that bounce off the internal organs. Those echoes are converted into images with the help of specialized computer programs.

Laparoscopic or endoscopic ultrasound: These ultrasounds provide more detailed images, as they allow for closer access to the bile duct area. Endoscopic and laparoscopic ultrasounds may be used to assist in removing tissue for a biopsy and determining if cancer has spread. During these procedures, a thin tube fitted with a light at the end is inserted through the mouth and down the throat, or through a small incision in the side of the body.

Endoscopic retrograde cholangiopancreatography (ERCP): During this procedure, an endoscope is inserted down the throat, followed by a smaller scope that dispenses dye into the bile ducts. X-rays are able to then pick up the dye and reveal any visible abnormalities. If necessary, doctors may also insert stents to unblock bile ducts during an ERCP.

Magnetic resonance cholangiopancreatography (MRCP): Similar to an MRI, this test takes thorough pictures of the bile ducts. Unlike the ERCP, it is noninvasive and does not use radiation.

Percutaneous transhepatic cholangiography: Useful in detecting bile duct cancer located inside the liver, this is a more invasive but more accurate procedure. For this test, doctors use a needle to inject dye into the bile ducts. X-rays are then able to detect any existing problems or blockages. PTC may show the exact location and size of bile duct cancer tumors, and determine if they may be removed surgically.

Bile Duct Cancer Stages

Accurate staging is crucial for developing the patient’s optimal bile duct cancer treatment plan. To begin, the type of bile duct cancer is classified based on its location.

Intrahepatic bile duct cancer starts inside the liver; perihilar (or hilar) bile duct cancer starts just outside the liver; and distal bile duct cancer starts near the small intestine.

Next, doctors determine the cancer’s severity by evaluating the size of the primary tumor and whether it has grown through the wall of the bile duct, if the cancer has reached nearby lymph nodes and if it has spread to other parts of the body.

Types of Staging

Each bile duct cancer is assigned a stage, which allows doctors to understand the cancer’s size, location and whether it has spread to other areas of the body. Staging is also helpful in determining a patient’s treatment plan.

Bile duct cancers are staged with the American Joint Committee on Cancer (AJCC) TNM (tumor, nodes and metastasis) system. Three staging variations are used, depending on where the cancer originated. Each is explained below.

Stages of Intrahepatic Bile Duct Cancers

This staging system is used on bile duct cancers that begin in the liver.

Stage 0: Abnormal cells are found in the mucosa, the innermost lining of the intrahepatic bile duct. They are not yet cancerous, but have the potential to be. Stage 0 is also called carcinoma in situ.

Stage 1a: The tumor is found only within an intrahepatic bile duct and is less than 5 cm (about 2 inches) in size.

Stage 1b: The tumor is found only within an intrahepatic bile duct and exceeds 5 cm (about 2 inches) in size.

Stage 2: The cancer has created two or more tumors that may or may not have spread into the blood vessels. Or, one tumor has spread into nearby blood vessels.

Stage 3a: The tumor has grown into the outer lining of abdominal organs (visceral peritoneum), but has not spread into nearby lymph nodes or other body areas.

Stage 3b: Cancer of any size has either spread to nearby lymph nodes or into nearby areas outside the liver, but not to distant areas of the body.

Stage 4: The cancer has spread into distant areas, such as the lymph nodes, lungs or into the bones.

Stages of perihilar (hilar) bile duct cancers

When bile duct cancer begins in the hilum, the area of the body outside of the liver, this staging system is used, as detailed below.

Stage 0: Also called high-grade dysplasia, abnormal cells have formed in the innermost layer of the perihilar bile duct. They are not yet cancerous, but have the potential to be in the future.

Stage 1: Cancer is found in the muscle or fibrous tissue of the perihilar bile duct.

Stage 2: Cancer has spread outside the bile duct and into nearby liver or fatty tissue.

Stage 3a: Cancer has spread into the blood vessels on one side of the liver.

Stage 3b: Cancer has spread into blood vessels or the liver or into its branches on both sides. Or, the cancer has grown into one bile duct and its main blood vessel on the opposite side.

Stage 3c: The cancer may be growing into nearby blood vessels and has spread into one to three nearby lymph nodes.

Stage 4a: Cancer has spread into four or more nearby lymph nodes, but not into more distant areas of the body. It may or may not be growing into nearby blood vessels.

Stage 4b: Cancer has spread into distant areas of the body, which may include the lungs, bones, lymph nodes or other parts of the liver.

Stages of distal bile duct cancers

Bile duct cancers that begin in the common bile duct formed by the liver and gallbladder, known as distal bile duct cancer, use this staging system, as listed below.

Stage 0: Abnormal cells have formed in the innermost tissue layer of the distal bile duct. It is not yet cancerous, but has the potential to become cancerous in the future.

Stage 1: Cancer is found in the wall of the distal bile duct and is less than 5 mm (about ⅕ of an inch) in size.

Stage 2a: The cancer has grown between 5 mm (about ⅕ inch) and 12 mm (about ½ inch) into the bile duct wall. Or, it has grown less than 5 mm and has spread into one to three nearby lymph nodes.

Stage 2b: The cancer has spread more than 12 mm (about ½ inch) into the bile duct wall. Or, it has grown 5 mm (about ⅕ inch) or more and also has spread into fewer than three nearby lymph nodes.

Stage 3a: Cancer is found in at least four nearby lymph nodes and has grown to any depth in the bile duct wall.

Stage 3b: The cancer has spread into nearby blood vessels or nearby arteries and may or may not also be in nearby lymph nodes.

Stage 4: The cancer has spread into distant areas of the body, which may include the abdominal lining, lungs, liver or lymph nodes.

It is common for patients to feel overwhelmed with the details of staging and new medical information. The care team is always able to answer questions or provide clarification.

How Fast Does Bile Duct Cancer Spread?

Bile duct cancer is known to be aggressive, which means it may spread quickly in some patients. It is often already in an advanced stage at the time of diagnosis. How fast it spreads to the liver, lymph nodes or nearby organs depends on the type of bile duct tumor and where it starts.

However, each cancer is different, and patient health outcomes will depend on the cancer’s stage, type and the patient’s overall health.