Primary liver cancer

The liver is the largest organ in the body, and is part of the digestive system. It is found on the right side of the abdomen, next to the stomach. It is under the ribs, just beneath the right lung and the diaphragm. The diaphragm is a sheet of muscle that separates the chest from the abdomen.

The liver is made up of two sections: the right and left lobes. Blood flows into the liver from the hepatic artery and the portal vein. Blood from the hepatic artery carries oxygen, while blood from the portal vein carries nutrients and waste products (toxins).

The liver performs several important functions including:

• producing bile to help dissolve fat so it can be easily digested
  storing and releasing glucose as needed
• storing nutrients
• making proteins needed for fluid balance and making protein
  to help the blood to clot
• breaking down substances, such as alcohol and drugs, and getting rid of waste products.

Unlike other internal organs, the liver can usually repair itself if injured. It can continue to function even when only a small part is working. After surgery or injury, a healthy liver can grow back to normal size in 6–8 weeks.

There are three different types of primary liver cancer.

• Hepatocellular carcinoma (HCC) – starts in the hepatocytes, the main cell type in the liver. HCC, also called hepatoma, is the most common type of primary liver cancer.
• Cholangiocarcinoma – starts in the cells lining the bile duct, which connects the liver to the bowel and the gall bladder. It is also called bile duct cancer.
• Angiosarcoma – a rare type of liver cancer starting in the blood vessels. It usually occurs in people over 70.

Primary liver cancer is one of the less common cancers in Australia. About 1600 people are diagnosed with it every year. It is more than twice as common in men, and the average age at diagnosis is 67.3

Primary liver cancer is becoming more common, mainly because the rate of hepatitis infection is increasing, and more people are developing serious damage from fatty liver disease. There is a link between hepatitis and liver cancer.

In most cases, primary liver cancer is related to long-term (chronic) infection caused by the hepatitis B or C virus.

Other causes of primary liver cancer aren’t always known, but some factors that increase the risk include:

• liver scarring (cirrhosis) – from hepatitis B or C, alcohol, fatty liver disease, or genetic disorders such as iron overload (haemochromatosis) or alpha-1 antitrypsin deficiency type 2 diabetes
• drinking too much alcohol
• eating a high-fat diet and/or being overweight or obese
• smoking tobacco
• exposure to certain chemicals or substances (such as aflatoxins or vinyl chloride).

What is cirrhosis?

Cirrhosis is a type of liver damage where healthy liver tissue is replaced with scar tissue. The scar tissue blocks the flow of blood through the liver and slows the processing of nutrients, hormones, drugs and naturally produced toxins. It also slows the production of proteins and other substances made by the liver.

Cirrhosis can develop over months or years.

Link between hepatitis and liver cancer

About 8 in 10 HCC cases worldwide can be linked to chronic hepatitis B infection.

Both hepatitis B and C are spread by contact with infected blood, semen or other body fluids. This can occur through sex with an infected partner or sharing personal items, such as razors, toothbrushes or needles, with an infected person.

The most common way that hepatitis B is spread is during birth, from mother to baby. If hepatitis is acquired in infancy or early childhood, it can lead to chronic hepatitis infection.

Chronic infection with hepatitis B affects the liver cells (hepatocytes). This stimulates the body’s immune system to attack the virus. The immune response causes liver inflammation, which can lead to ongoing damage that can cause liver cancer.

Primary liver cancer is more common in people with high rates of infection with hepatitis B or C virus. To reduce the spread of hepatitis B and the incidence of primary liver cancer, all at-risk people should be vaccinated against the virus. These include:

• migrants from South-East Asia, Africa and the Pacific Islands
• sexually active partners of infected individuals
• people in the same household as someone with hepatitis B
• recipients of blood products
• infants and children (as part of Australia’s National Immunisation Program).

If you are already infected with the virus, vaccination is not effective and you need regular tests to ensure you don’t develop health problems, including liver cancer. If you are concerned about hepatitis, talk to your doctor.