What Is Bile Duct Cancer?
Cancer starts when cells in the body start to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?
Bile duct cancer starts in a bile duct. To understand this cancer, it helps to know about the bile ducts and what they normally do.
Bile duct cancer starts in a bile duct. To understand this cancer, it helps to know about the bile ducts and what they normally do.
About the bile ducts
The bile ducts are a series of thin tubes that go from the liver to the small intestine. Their major job is to move a fluid called bile from the liver and gallbladder into the small intestine, where it helps digest the fats in food.
Different parts of the bile duct system have different names. In the liver it begins as many tiny tubes (called ductules) where bile collects from the liver cells. The ductules come together to form tubes called small ducts. These merge into larger ducts and then the left and right hepatic ducts. All of these ducts within the liver are called intrahepatic bile ducts.
The left and right hepatic ducts exit the liver and join to form the common hepatic duct in an area called the hilum. Lower down, the gallbladder (a small organ that stores bile) is joined to the common hepatic duct by a small duct called the cystic duct. This combined duct is called the common bile duct. The common bile duct passes through part of the pancreas before it joins with the pancreatic duct and empties into the first part of the small intestine (the duodenum) at the ampulla of Vater.
The left and right hepatic ducts exit the liver and join to form the common hepatic duct in an area called the hilum. Lower down, the gallbladder (a small organ that stores bile) is joined to the common hepatic duct by a small duct called the cystic duct. This combined duct is called the common bile duct. The common bile duct passes through part of the pancreas before it joins with the pancreatic duct and empties into the first part of the small intestine (the duodenum) at the ampulla of Vater.
Types of bile duct cancers by location
Cancer can start in any part of the bile duct system. Based on where the cancers are (see the picture below), they're grouped into 3 types:- Intrahepatic bile duct cancers
- Perihilar (also called hilar) bile duct cancers
- Distal bile duct cancers
Cholangiosarcomas in these different groups cause different symptoms.
Nearly all bile duct cancers or cholangiocarcinomas are adenocarcinomas, which are cancers that start in glandular cells. Bile duct adenocarcinomas start in the mucous gland cells that line the inside of the ducts.
Other types of bile duct cancers are much less common. These include sarcomas, lymphomas, and small cell cancers. Our information does not cover these other types of bile duct cancer.
Cancers that start in other organs can spread to the liver. These are called liver metastases or metastatic cancer to the liver. Their outlook and treatment are not the same as cancer that starts in the liver (such as hepatocellular carcinoma) or bile ducts (like cholangiocarcinoma), but instead depend on where the cancer started. For this reason, it’s important to know whether a tumor in the liver started in bile ducts (is a cholangiocarcinoma), or whether it's made up of cancer cells that started in another organ (like the colon) and spread to the liver (is metastatic cancer).
Intrahepatic bile duct cancers
These cancers start in the smaller bile duct branches inside the liver. Sometimes they're confused with cancers that start in the liver cells, which are called hepatocellular carcinomas , which are often treated the same way.Perihilar (also called hilar) bile duct cancers
These cancers start at the hilum, where the left and right hepatic ducts have joined and are just leaving the liver. These are also called Klatskin tumors. These cancers are grouped with distal bile duct cancers as extrahepatic bile duct cancers.Distal bile duct cancers
These cancers are found further down the bile duct, closer to the small intestine. Like perihilar cancers, these are extrahepatic bile duct cancers because they start outside of the liver.Types of bile duct cancer by cell type
Bile duct cancers can also be divided into types based on how the cancer cells look under the microscope.Nearly all bile duct cancers or cholangiocarcinomas are adenocarcinomas, which are cancers that start in glandular cells. Bile duct adenocarcinomas start in the mucous gland cells that line the inside of the ducts.
Other types of bile duct cancers are much less common. These include sarcomas, lymphomas, and small cell cancers. Our information does not cover these other types of bile duct cancer.
Benign bile duct tumors
Not all bile duct tumors are cancer. Bile duct hamartomas and bile duct adenomas are examples of benign (non-cancer) tumors.Other cancers in the liver
The most common type of cancer that starts in the liver – much more common than cholangiosarcoma – is hepatocellular carcinoma, which starts in cells that form the liver.Cancers that start in other organs can spread to the liver. These are called liver metastases or metastatic cancer to the liver. Their outlook and treatment are not the same as cancer that starts in the liver (such as hepatocellular carcinoma) or bile ducts (like cholangiocarcinoma), but instead depend on where the cancer started. For this reason, it’s important to know whether a tumor in the liver started in bile ducts (is a cholangiocarcinoma), or whether it's made up of cancer cells that started in another organ (like the colon) and spread to the liver (is metastatic cancer).
Key Statistics for
Bile Duct Cancer
Bile duct cancer (cholangiocarcinoma) is rare. About 8,000 people in the United States are diagnosed with it each year. This includes both intrahepatic (inside the liver) and extrahepatic (outside the liver) bile duct cancers. But the actual number of cases is likely to be higher, because these cancers can be hard to diagnose, and some might be misclassified as other types of cancer.
Bile duct cancer is more common in Southeast Asia, mostly because a parasitic infection that can cause bile duct cancer is much more common there.
Bile duct cancer can occur at younger ages, but it's seen mainly in older people. The average age of people in the US diagnosed with cancer of the intrahepatic bile ducts is 70, and for cancer of the extrahepatic bile ducts it's 72.
The chances of survival for patients with bile duct cancer depend to a large extent on its location and how advanced it is when it's found. For more on this, see Survival statistics for bile duct cancers.
Bile duct cancer is more common in Southeast Asia, mostly because a parasitic infection that can cause bile duct cancer is much more common there.
Parasites that
can lead
to cancer
Certain parasitic worms that can live inside the human body can also raise the risk of developing some kinds of cancer. These organisms are not found in the United States, but they can be a concern for people who live in or travel to other parts of the world.
Opisthorchis viverrini and Clonorchis sinensis are liver flukes (a type of flatworm) that have been linked to increased risk of developing cancer of the bile ducts. The bile ducts are tubes that connect the liver to the intestines. These infections come from eating raw or undercooked freshwater fish. They occur mostly in East Asia and are rare in other parts of the world.
Schistosoma haematobium is a parasite found in the water of some countries in the Middle East, Africa, and Asia. Infection with this parasite (an illness called schistosomiasis) has been linked to bladder cancer. Possible links to other types of cancer are now being studied as well.
Opisthorchis viverrini and Clonorchis sinensis are liver flukes (a type of flatworm) that have been linked to increased risk of developing cancer of the bile ducts. The bile ducts are tubes that connect the liver to the intestines. These infections come from eating raw or undercooked freshwater fish. They occur mostly in East Asia and are rare in other parts of the world.
Schistosoma haematobium is a parasite found in the water of some countries in the Middle East, Africa, and Asia. Infection with this parasite (an illness called schistosomiasis) has been linked to bladder cancer. Possible links to other types of cancer are now being studied as well.
Bile duct cancer can occur at younger ages, but it's seen mainly in older people. The average age of people in the US diagnosed with cancer of the intrahepatic bile ducts is 70, and for cancer of the extrahepatic bile ducts it's 72.
The chances of survival for patients with bile duct cancer depend to a large extent on its location and how advanced it is when it's found. For more on this, see Survival statistics for bile duct cancers.
Survival Rates
for Bile Duct
Cancer
Survival rates are often used by doctors as a standard way of discussing a person’s prognosis (outlook). Some people may want to know the survival statistics for people in similar situations, while others might not find the numbers helpful, or might even not want to know them.
When discussing cancer survival statistics, doctors often use a number called the 5-year survival rate. The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Of course, some of these people live much longer than 5 years.
Five-year relative survival rates, such as the numbers below, assume that some people will die of other causes and compare the observed survival with that expected for people without the cancer. This is a better way to see the impact of the cancer on survival.
To get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. Improvements in treatment since then may result in a better outlook for people now being diagnosed with bile duct cancer.
There are some important points to note about the survival rates below:
These statistics come from the National Cancer Institute’s SEER program and are based on people diagnosed with bile duct cancer in the years 2000 to 2006. SEER does not separate these cancers by AJCC stage, but instead puts them into 3 groups: localized, regional, and distant. Localized is like AJCC stage I. Regional includes stages II and III. Distant means the same as stage IV.
SEER also does not separate perihilar bile duct cancers from distal bile duct cancers. Instead, these are grouped together as extrahepatic bile duct cancers.
Survival rates are often based on previous outcomes of large numbers of people who had the disease, but they can’t predict what will happen with any particular person. Many other factors can also affect a person’s outlook, such as their age and overall health, and how well the cancer responds to treatment. Even when taking these other factors into account, survival rates are at best rough estimates. Your doctor can tell you how the numbers above apply to you, as he or she knows your situation best.
When discussing cancer survival statistics, doctors often use a number called the 5-year survival rate. The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Of course, some of these people live much longer than 5 years.
Five-year relative survival rates, such as the numbers below, assume that some people will die of other causes and compare the observed survival with that expected for people without the cancer. This is a better way to see the impact of the cancer on survival.
To get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. Improvements in treatment since then may result in a better outlook for people now being diagnosed with bile duct cancer.
There are some important points to note about the survival rates below:
These statistics come from the National Cancer Institute’s SEER program and are based on people diagnosed with bile duct cancer in the years 2000 to 2006. SEER does not separate these cancers by AJCC stage, but instead puts them into 3 groups: localized, regional, and distant. Localized is like AJCC stage I. Regional includes stages II and III. Distant means the same as stage IV.
SEER also does not separate perihilar bile duct cancers from distal bile duct cancers. Instead, these are grouped together as extrahepatic bile duct cancers.
Intrahepatic bile duct cancer
| Stage | 5-year relative survival |
| Localized | 15% |
| Regional | 6% |
| Distant | 2% |
Extrahepatic bile duct cancer
| Stage | 5-year relative survival |
| Localized | 30% |
| Regional | 24% |
| Distant | 2% |
No comments:
Post a Comment