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Cholangiocarcinoma, also known as bile duct cancer, is a rare and aggressive type of cancer that forms in bile ducts. Bile ducts are thin tubes that carry a digestive fluid called bile from your liver to other digestive organs.

In cholangiocarcinoma, a gene in the cells lining the bile duct changes abnormally, causing the cells to grow and divide without stopping. These cancer cells form tumors. Over time, some cells can break off and spread to other parts of the body. This is called metastasis.

Cholangiocarcinoma is often described according to where it starts

Intrahepatic cholangiocarcinoma
starts in the bile ducts inside the liver
Extrahepatic cholangiocarcinoma
starts in the bile ducts outside the liver

The location of cholangiocarcinoma may affect how healthcare professionals treat the disease.

Most people with cholangiocarcinoma do not have symptoms until the disease becomes more advanced. For this reason, it is often difficult for healthcare professionals to diagnose the disease early.

While surgery may be used to remove the tumor in some cases, this may not be an option if the tumor takes up too much of the liver, or if the disease has spread to other parts of the body.


As mentioned previously, cholangiocarcinoma is caused by an abnormal change to a gene that causes cells inside the bile ducts to grow and divide without stopping.

There are different types of abnormal gene changes or defects that can lead to cholangiocarcinoma. These changes may include:

Gene fusion

This occurs when parts of two different
genes abnormally join together.

Gene amplification

This occurs when the number of copies of a gene is increased beyond the normal number.


This is a change to a specific
portion of the normal gene.

What is an FGFR2 fusion?

One specific type of gene fusion that can cause cholangiocarcinoma is called an FGFR2 fusion.

  • An FGFR2 fusion is a change to the FGFR2 gene, which causes your cells to make an abnormal version of the FGFR2 protein
  • This abnormal FGFR2 protein can lead to tumor growth in bile duct cancer

In fact, up to 16% of people with intrahepatic cholangiocarcinoma have an FGFR2 fusion.

Click here to learn how PEMAZYRE targets FGFR2 fusions in cholangiocarcinoma.

What is the difference between “genetic” testing and “genomic” testing?

“Genetics” and “genomics” are two words that sound similar, but mean different things.

  • Genetics refers to the study of single genes and how they are involved in passing down traits from generation to generation. Genetic testing helps identify genetic conditions that may be inherited like sickle cell anemia and cystic fibrosis.
  • Genomics is the study of how all of a person’s genes interact with each other and the environment. An FGFR2 fusion is an example of a genomic change that can cause cholangiocarcinoma.
Treatment with PEMAZYRE

Find out how PEMAZYRE works to target FGFR2 fusions in people with previously treated cholangiocarcinoma that has spread or cannot be removed surgically.

Learn more about PEMAZYRE