Cholangiocarcinoma is bile duct cancer, a serious and potentially life-threatening type of cancer. There is no known single cause, but risk factors include liver disease and congenital bile duct abnormalities.[1] There is growing evidence that asbestos exposure may also be a factor because of the inflammation and damage it causes.
What Is Bile Duct Cancer?
Cholangiocarcinoma is a cancer of the bile ducts. Bile ducts are tubes that connect the liver, small intestines, and gallbladder. These ducts transport bile from the liver and gallbladder to the intestines. Bile is a fluid the body uses to digest fats.
The liver has smaller and larger ducts called the intrahepatic bile ducts. The common bile ducts are where these smaller ducts connect with the cystic duct outside the liver. The common bile duct moves through the pancreas and into the small intestine.[2]
When cancer originates in these ducts, it is referred to as cholangiocarcinoma. A primary tumor may grow in the intrahepatic ducts, just outside the liver, or the ducts that run through the pancreas and small intestines. There are three subtypes of bile duct cancer:
- Intrahepatic. When the cancer begins in the ducts inside the liver, it is called intrahepatic cholangiocarcinoma. This is sometimes also referred to as a type of liver cancer.
- Extrahepatic. Extrahepatic cholangiocarcinoma occurs in ducts outside of the liver, closest to the small intestine.
- Hilar. Cancer in bile ducts outside but closer to the liver is called hilar cholangiocarcinoma.
How Many People Get Cholangiocarcinoma?
This is a rare type of cancer, although not as rare as mesothelioma. Approximately 8,000 people per year receive a diagnosis of cholangiocarcinoma, compared to 3,000 mesothelioma diagnoses in the U.S. Bile duct cancer is more common in southeast Asia due to a parasite.[3]
Symptoms of Cholangiocarcinoma
Several potential symptoms of cholangiocarcinoma include:[1]
- Jaundice
- Abdominal pain
- Weakness
- Itchy skin
- Weight loss
- Fever
- Fatigue
- White bowel movements
How Is Bile Duct Cancer Diagnosed?
Diagnosing cholangiocarcinoma begins with a physical examination and blood tests. Tumor markers can also help aid in the work-up of this cancer, which is done by simple blood tests. A blood test may also be performed to examine liver function, providing a useful diagnostic tool.[4]
The patient may also receive an abdominal ultrasound. This is a special imaging test that helps physicians see soft tissues and tumors in the bile ducts. A patient may also receive a CT or MRI scan to understand tumor size and location better.[4]
If doctors suspect bile duct cancer, they may insert an endoscope through the mouth to the stomach and intestines to provide a closer view.[4]
Doctors may also perform a cholangiography, which is a way of getting an image of the bile ducts. During this special procedure, dye is injected into the ducts. Then, an X-ray is taken so doctors can detect any tumors.[5]
Finally, doctors may biopsy suspected tumors. A biopsy involves removing a small amount of tissue and examining it under the microscope to detect cancer cells.[4]
What Causes Cholangiocarcinoma?
Experts do not fully understand what causes cholangiocarcinoma. Ultimately, all cancers are caused by cell DNA damage, which causes tumors to form.
There are some known risk factors for cholangiocarcinoma. These may not specifically cause this cancer, but they may increase the risk:[1]
- Having a disease called primary sclerosing cholangitis, a hardening and scarring of the bile ducts
- Congenital bile duct problems, including cysts or irregular bile ducts from birth
- Contracting a parasite of the liver, which is more common in Southeast Asia and can come from consuming raw and under-cooked fish
- Having chronic liver disease
- Age; most people diagnosed with cholangiocarcinoma are fifty or older.
- Smoking
What Chemicals Cause Cholangiocarcinoma?
While they might not directly cause bile duct cancer, exposure to certain chemicals seems to be a risk factor for it. These include chemicals used in the automotive industry and in rubber plants:[6]
- Dioxin
- Nitrosamine
- Polychlorinated biphenyls (PCBs)
Asbestos and Cholangiocarcinoma
Recent studies have found connections between asbestos exposure and cholangiocarcinoma. One study that examined thousands of Europeans diagnosed with bile duct cancer discovered that those exposed to asbestos in the workplace were more likely to develop cholangiocarcinoma, specifically intrahepatic bile duct cancer.[7]
Another smaller Italian study also investigated workers diagnosed with this type of cancer. This study specifically examined construction workers. The study indicated a significant connection between intrahepatic bile duct cancer and workers exposed to asbestos.
Researchers suggest asbestos may trigger chronic inflammation in the bile ducts, ultimately leading to cancer development. This study also noted a worldwide increase in the incidence of cholangiocarcinoma over the past thirty years. This trend could be due to asbestos exposure.[8]
In a study published in 2020, researchers looked at the connection between asbestos and intrahepatic cholangiocarcinoma. Some patients with this cancer have asbestos fibers in the liver. The researchers suggest they migrated there after inhalation or ingestion. Once stuck in the liver, the fibers caused damage over the years that developed into malignancy.[9]
Treatment for Cholangiocarcinoma
Cholangiocarcinoma treatment options may include surgery, chemotherapy, immunotherapy, and/or radiation. The most appropriate treatment depends on the stage of the cancer at diagnosis and the patient’s overall health.
The stage provides information about the size of the tumor and if it has spread to any lymph nodes or distant organs.[8] Chemotherapy can help manage cholangiocarcinoma. This involves administering drugs that target and kill fast-growing cancer cells. Radiation therapy, which involves a focused, high-energy beam to kill cancer cells, is also possible.[4]
Other possible treatments include photodynamic therapy. Photodynamic therapy causes light-sensitive chemicals to accumulate inside cancer cells. Then lasers activate the chemicals, killing the cancerous cells. In some cases, a liver transplant may have the potential to cure cholangiocarcinoma.[4]
Cholangiocarcinoma Life Expectancy
The prognosis for cholangiocarcinoma isn’t very positive. It is generally considered to be an incurable cancer. Studies report an average survival time after treatment of just six months.[11]
Other sources report disappointing five-year survival rates, which measure the percentage of people alive five years after a diagnosis or beginning treatment.
For cholangiocarcinoma overall, the five-year survival rate is just 9%. For localized cancer, it is higher, but still only 24%.[12]
Avoiding Asbestos and Prevention
Knowing more about the causes of cholangiocarcinoma can help people avoid risk factors that could lead to a cancer diagnosis. People are less likely to be exposed to asbestos today, but it is still a risk factor.
It is important to avoid asbestos, especially in older homes, and rely on asbestos professionals to find and abate the material.[13] It is also important to be aware of safety regulations in the workplace, especially where exposure is possible.
Cholangiocarcinoma is a cancer that may be triggered by asbestos exposure; however, many people develop the disease without experiencing any known exposure.
Regardless of the cause, it is important to seek a diagnosis and treatment as early as possible. If you have been diagnosed with bile duct cancer and you have been exposed to asbestos in the past, talk to an asbestos attorney to determine your legal options.
