Primary liver cancers are defined as malignant tumors that grow on the surface or inside the liver for example on the liver’s blood vessels or bile duct. Primary liver cancers are rare, comprising less than 10% of all liver cancers. Secondary liver cancers are defined as having a different point of origin than the liver, and then they metastasize to the liver or its structures. Secondary liver cancers account for more than 90 percent of liver cancer cases, given that part of the liver’s job is to collect and process blood waste products and toxins.
Liver Cancer: By the Numbers
- 90 percent of cases occur in people aged 45 or older.
- Primary liver cancer is the fifth most common cause of death by cancer in men and the ninth most common in women.
- In 2008, there were 21,370 people diagnosed with liver cancer in the United States, and the disease claimed the lives of approximately 18,410 people.
Liver Cancer: Patient Demographic
Instances of liver cancer are doubled in populations of African-Americans, Hispanics, Asian-Americans, and Pacific Islanders as compared to whites. It also is contracted by many more men than women. The ratio of man-to-woman diagnoses is approximately 70:30.
Researchers do not know for sure, but they posit that men produce more of a certain protein known as IL-6 in response to a liver injury. Too much IL-6 can cause chronic inflammation, which in turn can lead to cancer. Women’s hormonal profiles on the other hand show that estrogen inhibits high levels of IL-6, causing the rates of liver cancer to be lower for females than males.
Certain diseases place people at risk for developing primary liver cancer. These are:
- Hepatitis B
- Hepatitis C
There are different kinds of liver cancer, depending on the cells in which it begins:
Cancer Profile: Hepatocellular Carcinoma
Hepatocellular carcinoma, also called hepatoma, accounts for approximately 75% of all primary liver cancers. This kind of carcinoma originates in the liver’s base cells, known as hepatocytes, and the malignancies occur in two forms:
- As small cancer nodules that are spread throughout the liver. This more common pattern is often seen in people with cirrhosis of the liver.
- As an isolated, growing tumor that only spreads late in the disease.
Cancer Profile: Intrahepatic Cholangiocarcinomas
This liver cancer originates in the bile ducts. Bile is a liquid that takes fatty acids from food and body waste and breaks them down. Once broken down, they are transported to the gallbladder for removal. Often this cancer occurs outside the liver on the ducts. This cancer accounts for 10 percent to 20 percent of liver cancers.
Cancer Profile: Hemangiosarcomas and Angiosarcomas
Sarcoma cancers are rare and rapid-growing cancers that start in the blood vessels. Researchers believe that they are linked to an inherited condition known as hemochromatosis. These sarcomas may also be caused by toxic chemicals. The disease can be slowed by cancer treatments such as chemotherapy and radiation, but prognosis is poor, with most patients surviving for approximately 1 year post-diagnosis.
Cancer Profile: Hepatoblastoma
This is a rare cancer that occurs in children aged 0 – 4. 7 out of 10 children with the disease can be treated successfully. The survival rate when found and treated early is greater than 90 percent.
Benign Liver Tumors
From time to time, benign tumors can grow in any organ, including the liver. Benign tumors do not spread and do not require treatment. Symptoms are minimal if at all. The only real cause for concern is if the tumor causes bleeding or pain, which may indicate that it is rupturing. If unusual symptoms manifest quickly, a visit to your health care team will be beneficial.