Liver Cancer: Introduction
What is cancer?
Cancer is when cells in the body change and grow out of control. Your body is made up of tiny building blocks called cells. Normal cells grow when your body needs them, and die when your body does not need them any longer.
Cancer is made up of abnormal cells that grow even though your body doesn't need them. In most cancers, the abnormal cells grow to form a lump or mass called a tumor. If cancer cells are in the body long enough, they can grow into (invade) nearby areas. They can even spread to other parts of the body (metastasis).
What is liver cancer?
Liver cancer is cancer that starts in your liver. This is also called primary liver cancer. Primary liver cancer is not the same as cancer that started somewhere else in the body and then has spread (metastasized) to the liver. Cancer that starts in another organ, such as the colon, breast, or lung, and then spreads to the liver is called secondary liver cancer. Secondary liver cancer is more common in the United States than primary liver cancer. Cancer that has spread to the liver from somewhere else is treated like the original cancer. For instance, lung cancer that has spread to the liver is treated like lung cancer.
Understanding the liver
The liver is a large, pyramid-shaped organ that lies behind the ribs on the right side of the body. It’s under the right lung. It is divided into right and left lobes.
The liver helps break down nutrients. These include sugars, starch, fats, and proteins. It also stores some of these. The liver also makes proteins, such as albumin. This helps the body balance fluids. It also makes clotting factors, which help blood thicken or clot when a person is bleeding. Bile made in the liver is important for digesting food and for other bodily functions.
One of the liver’s most important jobs is to filter out and destroy toxins in the body. When the liver isn’t working well, chemicals can build up inside the body and cause damage.
What types of cancer start in the liver?
The main types of primary liver cancer include:
Hepatocellular carcinoma. This is the most common liver cancer. It’s also called hepatoma. About four out of every five primary liver cancers are of this type. This type of cancer starts in the main liver cells called hepatocytes.
Intrahepatic cholangiocarcinoma. About 10–20% of all liver cancers are cholangiocarcinomas. These cancers start in the bile ducts. These are small tubes where bile leaves the liver and goes into the gallbladder and intestines during digestion. This type of cancer can also start in the bile ducts outside the liver.
Hepatoblastoma. This is a rare liver cancer often found in children.
Angiosarcoma. This is another uncommon form of liver cancer. It starts in blood vessels inside the liver.
Several types of non-cancerous (benign) tumors can also form in the liver. These include hemangiomas, hepatic adenomas, and focal nodular hyperplasia. These tumors don’t spread to other parts of the body. But they can still cause problems if they grow large enough.
Talk with your healthcare provider
If you have questions about liver cancer, talk with your healthcare provider. Your healthcare provider can help you understand more about this cancer.
Liver Cancer: Stages
What does the stage of cancer mean?
The stage of a cancer is how much and how far the cancer has spread in your body. Your healthcare provider uses exams and tests to find out the size of the cancer and where it is. He or she can also see if the cancer has grown into nearby areas, and if it has spread to other parts of your body. The stage of a cancer is one of the most important things to know when deciding how to treat the cancer.
What are the stages of liver cancer?
Several systems can be used to divide liver cancer into stages. Doctors in different parts of the world might use different systems.
AJCC TNM system
The American Joint Committee on Cancer (AJCC) TNM staging system is often used to describe how much a cancer has grown.
Here is what the letters mean in the TNM system:
T describes the size of the main (primary) tumor and how far it has spread inside the liver and nearby areas.
N says whether the cancer has reached the nearby lymph nodes.
M says whether the cancer has spread (metastasized) to other organs in the body, such as the lungs or bones.
Once your doctor knows your T, N, and M status, he or she uses this information to assign the cancer an overall stage. Your doctor uses Roman numerals from I (the earliest stage) to IV (the most advanced stage).
Stage I. There is a single tumor in the liver that has not grown into any blood vessels.
Stage II. There is a single tumor in the liver that has grown into blood vessels. Or there are several tumors in the liver, but none is wider than 5 centimeters (about 2 inches).
Stage IIIA. There are many tumors in the liver and at least one is larger than 5 centimeters (about 2 inches). The cancer has not spread to nearby lymph nodes or to areas outside of the liver.
Stage IIIB. The cancer is growing into a branch of one of the main blood vessels in the liver (the portal or hepatic veins). It has not reached the lymph nodes or other organs.
Stage IIIC. The cancer has spread to nearby organs other than the gallbladder, which lies directly under the liver. Or the cancer has extended into the outer layer of tissue that covers the liver. The cancer has not spread to the lymph nodes or distant organs.
Stage IVA. Tumors can be of any size, but the cancer has spread into lymph nodes near the liver. The cancer has not yet reached distant organs.
Stage IVB. The cancer has spread to distant organs, such as the lungs, bones, or brain. It may not be clear that the cancer has invaded nearby blood vessels and lymph nodes.
Other staging systems
How far the cancer has grown or spread is important in figuring out treatment. But your doctor will look at other factors, too. For example, before doing surgery to remove the tumor, your doctor will want to know how the rest of your liver is working. He or she will want to be sure there would be enough healthy liver remaining after surgery. Some other staging systems look at liver function. These systems include the Okuda system and Barcelona Clinical Liver Cancer (BCLC) system. Talk with your doctor if you have questions about which system your doctor uses.
Talking with your healthcare provider
Once your cancer is staged, your healthcare provider will talk with you about what the stage means for your treatment. Make sure to ask any questions or talk about your concerns.