This is the third part of our series about the condition based on our patient booklet “Fast Facts for Patient and Supporters: Cholangiocarcinoma”. This article gives information on diagnostic tests and procedures as well as staging of cholangiocarcinoma.

Diagnostic Tests and Procedures

There are different types of imaging and procedures that can be carried out at this time. The decision about which to use will depend on availability in your area and your symptoms. Your doctor will arrange for appropriate tests for you.

Tumor Markers (CEA, CA 19-9)

• Uses blood
• Measures the levels of certain proteins in your blood

Ultrasound

• Uses sound waves
• Good for taking pictures of small areas

CT (Computed Tomography)

• Uses X-rays to take pictures of many parts of the body from different angles
• You may have to drink a contrast dye and/or have contrast dye injected to help make the picture clearer

MRI (Magnetic Resonance Imaging)

• Uses radio waves and magnets to take pictures of the body from different angles
• You may have contrast dye injected to help make the picture clearer (the dye is different from the contrast used for CT scans)

MRCP (Magnetic Resonance Cholangiopancreatography)

• A type of MRI that looks specifically at the bile ducts
• Helps to see whether the cancer has caused a blockage in the bile duct

PET (Positron Emission Tomography)

• Uses sugar with a radioactive tag to identify active cancer cells
• Can be combined with CT images
• Often used if CT or MRI is not clear

EUS (Endoscopic Ultrasound)

• Uses a thin tube-shaped device with a camera at the end (an endoscope)
• Uses ultrasound waves as well as the camera to detect a tumor
• A piece of the tumor (biopsy) may be taken with a needle at the same time

ERCP (Endoscopic Retrograde Cholangiopancreatography)

• Uses an endoscope with a camera at the end to look into the bile ducts
• A thin flexible tube (catheter) is passed through the endoscope
• Dye is injected into the area while X-rays are taken
• Stents may be put into the bile duct (see page 32)
• A biopsy may be taken with a needle at the same time

PTC (Percutaneous Transhepatic Cholangiography)

• A dye (contrast medium) is injected directly through the skin into a bile duct to help define the position of the bile ducts
• X-rays are taken to see where the dye flows within the bile ducts Laparoscopy (a surgical procedure)
• Small cuts are made in the abdomen and a laparoscope (similar to an endoscope) is inserted to look inside the abdomen
• A sample can be taken from the tumor (biopsy)

Biopsy

• Uses a needle to obtain a sample of the tumor
• Can be done surgically or with endoscopy, using ultrasound or CT

Biomarker Testing

• Uses a sample of the tumor (obtained during a biopsy)
• Looks for changes (mutations, fusions, deletions) in the DNA of the tumor that may be used for treatment decision-making
• Is used for tumors that have spread to other areas of the body (metastatic tumors)

Circulating Tumor DNA

• Is currently thought of as experimental
• Measures tumor DNA that is floating freely in the bloodstream
• Can be used to identify changes in the DNA that may be used for treatment decision-making
• May be done if/when a tumor biopsy is not possible, after a confirmed diagnosis of cholangiocarcinoma based on a previous tumor biopsy

Staging of Cholangiocarcinoma

Your cholangiocarcinoma will be intrahepatic or extrahepatic, depending on where it is.

Doctors “stage” cancers so they can describe the features consistently and agree on the best treatment approaches. Your cancer stage is a score that describes your cancer. It will be used to make your treatment plan in conjunction with other information such as your overall health and tumor biomarker profile.

Staging for hepatobiliary cancers is based on:

• T (tumor) score, which describes the size of the main (primary) tumor and whether it has grown into nearby areas
• N (node) score, which describes whether the cancer has spread to lymph nodes and if it has, how many lymph nodes are affected
• M (metastasis) score, which describes whether the cancer has spread to other places in the body.

The specific T, N and M scores that give the cancer stage are slightly different for intrahepatic and extrahepatic cholangiocarcinomas and gallbladder tumors. The next section is a general guide, but your doctor can give you more information about your cancer stage.

• Stage I: the tumors are small, and have not spread to nearby blood vessels, lymph nodes or organs, or to distant organs.
• Stage II: there may be more than one tumor, or a tumor may have grown into nearby blood vessels. The cancer has not spread to nearby lymph nodes or organs or to other places in the body.
• Stage III: the tumor has grown into nearby blood vessels or organs. The tumor has spread to nearby lymph nodes, but it has not spread to other places in the body.
• Stage IV: the tumor has spread to other places in the body (metastasized).

Another factor used in staging is the grade (G). A grade is assigned to your tumor based on how differentiated it is – how much the cancer cells look like normal cells under the microscope. If a tumor is well differentiated, it looks more like normal tissue than a poorly differentiated tumor. In general, poorly differentiated tumors tend to grow and spread more quickly than well-differentiated tumors.

The grading system is:

• GX: grade cannot be assessed
• G1: well differentiated
• G2: moderately differentiated
• G3: poorly differentiated

Knowledge Point

Cancer is said to be localized when it is confined to the organ where it started and has not spread to another place in the body.

Metastasis describes the spread of cancer to another part of the body. It usually happens when cancer cells break away from the main tumor and travel around the body in the bloodstream or lymphatic system to a different place. When the cells settle and start to grow in other organs, they form new tumors.

The new tumor is called a secondary, a metastasis or metastatic cancer. It has the same characteristics as the primary tumor, and is the same cancer type, even though it is in a different place. Cholangiocarcinoma that has spread to another place in the body (such as a lung) is still considered to be bile duct cancer (cholangiocarcinoma).

Whether cancer is localized (located only in one organ) or metastasized (spread to multiple areas of the body) makes a difference to the type of treatment that is recommended.

Information based on Fast Facts for Patients and Supporters: Cholangiocarcinoma (Karger, 2021).