What causes liver cancer?

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer develops due to several cellular processes. One major cause is genetic mutations in liver cells, which may occur naturally or be induced by environmental exposure. These mutations interfere with normal cell regulation and lead to abnormal growth and tumour formation.

Chronic inflammation in the liver caused by long-standing conditions such as cirrhosis or exposure to carcinogens, can also damage cellular DNA and accelerate the development of HCC. Prolonged contact with harmful substances like industrial chemicals, can also lead to significant cellular damage that may cause liver cancer.

What are the risk factors for liver cancer?

People with risk factors are more likely to develop primary liver cancer or HCC. The more risk factors a person has, the greater the chance that liver cancer will develop. However, many people with known risk factors do not develop the disease.

If you think you may be at risk for liver cancer, discuss it with your doctor to see how to manage your risk.

Factors that increase the risk of primary liver cancer:

• Chronic infection with hepatitis B or C

  • Hepatitis B is the most common cause of primary liver cancer. Hepatitis B can be transmitted from an infected mother to her baby during pregnancy. In the adult setting, hepatitis B and C can be transmitted by contact with infected body fluids, for example saliva, blood, sperm and other secretions. Infection of liver cells with hepatitis B viruses causes DNA damage, which can lead to liver cirrhosis (hardening of the liver).
    
  • Hepatitis C causes primary liver cancer by damaging the liver through chronic inflammation, which can also lead to liver cirrhosis.
  • An individual with hepatitis B or C is 100 times more likely to get liver cancer compared to an individual without hepatitis B or C.

• Excessive alcohol consumption

  • Repeated and excessive alcohol abuse can lead to liver cirrhosis and liver cancer.

• Non-alcoholic fatty liver disease (NAFLD)

  • Almost half the adult population in Singapore may have NAFLD. This can progress to non-alcoholic steatohepatitis (NASH), liver cirrhosis and primary liver cancer.
  • NAFLD and NASH are increasingly important causes of HCC in Singapore and globally.
  • NAFLD is related to diabetes mellitus and obesity. However, many patients with NAFLD are not obese.
    

• Cirrhosis or hardening of the liver

  • People with liver cirrhosis, an irreversible condition in which healthy liver cells are replaced by scar tissue, are at greater risk for developing liver cancer and should undergo regular screening.
  • Cirrhosis happens because of liver damage from a variety of causes, but the most common causes are hepatitis B or C infections, fatty liver and excessive alcohol consumption.

• Exposure to poison (aflatoxins)

  • Aflatoxins are harmful food contaminants made by certain moulds that grow on poorly stored grains and nuts.

• Inherited metabolic diseases

  • Inherited metabolic diseases that affect the liver such as haemachromatosis, which causes excess deposits of iron in the body, puts a person at a higher chance of developing primary liver cancer.