Overview
Liver cancer starts in the liver, the large football-shaped organ in the right side of your abdomen, below your diaphragm, and on top of your stomach, intestines, and right kidney. The liver has several functions, including filtering alcohol, drugs, and other poisonous matter from the bloodstream, creating bile that flows to the intestines to aid in digestion, regulating blood clotting, resisting infections, and metabolizing and storing necessary chemicals that are absorbed through the intestine that your body needs to function. All of the blood in your body flows through the liver, and this makes it susceptible to cancer originating elsewhere in the body. The human body cannot survive without the liver.
The liver contains many different types of cells, and as such, several different types of tumors and cancers can form there. Not all tumors that form in the liver are cancerous, and the treatment and survival rates for liver cancer vary depending on what type of tumor or cancer you have.
Some types of liver cancer include:
Hepatocellular Carcinoma (HCC). This is the most common form of liver cancer. Nearly 75% of all liver cancers are this type. HCC usually occurs after alcohol-induced cirrhosis of the liver or hepatitis B or C infections.
Cholangiocarcinoma. Also called bile duct cancer, this type of liver cancer makes up between ten and twenty percent of all liver cancers. It occurs in the small tubes or ducts that carry bile from the liver to the intestine.
Angiosarcoma: Accounting for one percent of liver cancers, this type starts in the blood vessels and spreads outward. This cancer grows quickly and is frequently diagnosed at a late stage.
Liver cancer can form inside the liver. This is called primary cancer. If the cancer forms elsewhere in the body and metastasizes to the liver, it is called secondary cancer. The majority of liver cancer in the United States is the secondary type. Primary liver cancer only makes up about two percent of cancer cases in the country per year. It is far more common in countries outside the United States, likely due to the lack of vaccinations against the various forms of hepatitis, which can increase the risk of contracting primary liver cancer greatly.
The larger number of non-U.S. cancer cases may also be the result of the presence of aflatoxins, poisonous chemicals that appear in mold that grows on peanuts, corn, and other grains. Food safety regulations in the United States limit aflatoxins in our food supply, but aflatoxins are estimated to cause 40% of the cases of primary liver cancer in Africa.
Per the CDC, about 34,500 people will contract liver cancer this year in the United States, and around 27,000 will die from it. The average age at diagnosis is 67.
Symptoms
Symptoms of liver cancer don’t usually manifest until the cancer has been active for some time. The symptoms can be hard to detect and can resemble symptoms from other diseases, so make sure and talk to your doctor if you experience any of the following:
- Abdominal pain on the right side
- Jaundice (yellowing of the whites of the eyes and skin)
- Weight loss
- Nausea
- Vomiting
- Fatigue
- A hard lump on the right side just below the rib cage
- Pain below the right shoulder blade
- Itching
- Swollen legs
- Fever
- Chills
- Night sweats
Causes
Liver cancer develops like other cancers: the DNA in the cells in your liver mutate and begin to divide and multiply rapidly. Exactly what causes these mutations varies. Sometimes the exact cause is known, but in many cases, the liver can develop cancer with no known cause. Some known causes include:
- Hepatitis infection. If you suffer from a chronic hepatitis B or hepatitis C infection, you are at high risk of developing liver cancer.
- Aflatoxins are poisons that develop in mold that grows on improperly stored food. Data has shown that ingesting large amounts of these chemicals greatly increases the risk of developing liver cancer.
- Data has shown that long-term exposure to certain chemicals like vinyl chloride or arsenic can result in liver cancer.
Risk Factors
There are several risk factors for developing liver cancer, such as:
- Chronic hepatitis infection. This is the single largest risk factor for liver cancer worldwide.
- Smoking tobacco greatly increases the risk of a variety of cancers.
- Most people who develop liver cancer have some form of cirrhosis, which is a condition that causes scar tissue to form in the liver. Cirrhosis can be caused by excessive alcohol consumption or hepatitis.
- Men are much more likely to contract liver cancer than women.
- The highest rates of liver cancer are found in Asian Americans and Pacific Islanders. The next highest rates occur in Hispanics, then Alaska Natives/American Indians, then African Americans. The lowest incidence of liver cancer by ethnicity is found in whites.
- Heavy alcohol consumption. Consuming more than a moderate amount of alcohol every day over a long period can cause severe damage to the liver and increase the risk of cancer.
- Inherited genetic diseases. Certain genetic conditions that affect your metabolism, like Wilson’s disease, can increase the risk of liver cancer.
- Data shows that diabetics have two to three times the risk of developing liver cancer as those without diabetes.
- Non-alcoholic fatty liver disease. This disease causes an excessive amount of fatty tissue around the liver and can lead to liver cancer.
- Steroid use. Long-term anabolic steroid use has been shown to increase the risk of liver cancer.
Survival Rates
The American Cancer Society lists the combined five-year survival rate of liver cancer at twenty percent. This number is determined by reviewing statistics in the National Cancer Institute’s SEER database SEER stands for Surveillance, Epidemiology, and End Results. The database tracks three different stages of cancer:
- Localized: The cancer has remained inside the liver. Survival rates for this type are 34%.
- Regional: The cancer has spread to surrounding tissues like the bile duct or lymph nodes. Survival rates for this type are 12%.
- The cancer has spread to surrounding organs, bones, or brain. Survival rates for this type are three percent.
Treatment for liver cancer usually starts with surgery, though this varies, depending on the type of cancer you contract and how long it has been active. If your liver function is good and the cancerous portion is localized, your doctor may recommend surgery to remove it. If the cancer is caught early and a donor organ is available, they may also recommend a full liver transplant.