In Canada, primary liver cancer (also known as hepatocellular carcinoma or HCC) accounts for 2% of cancer deaths in men and 0.7% in women, while in other parts of the world such as Africa, Southeast Asia and China, it might reach up to 83%. (GLOBOCAN: Cancer fact sheets) According to the Canadian Liver Foundation, the high prevalence of people carrying the hepatitis B virus and having liver cirrhosis may account for this geographic discrepancy.
Most often primary liver cancer is found in patients with a pre-existing or underlying disease. While the exact cause is not known, there are a number of risk factors to consider:
- Chronic liver disease.
- Hepatitis B or C.
- Inherited liver disease such as hemochromatosis (accumulation of iron in the liver), as well as alpha-1 antitrypsin deficiency, which leads to liver fibrosis.
- Cirrhosis (scar tissue in the liver), usually caused by excessive alcohol consumption and chronic hepatitis B or C or non-alcoholic steatohepatitis (fatty liver disease), which causes inflammation and can lead to scarring and fibrosis.
- Tobacco increases the risk if there is already an underlying disease.
- Anabolic steroids, both prescribed and non-prescribed, when used long-term.
- Obesity that may cause liver damage when excess fat accumulates in the liver, causing fibrosis and scarring.
- Betel quid leaf chewing. Consumed mostly in Southeast Asia, betel chewing is one of the most popular psychoactive substances in the world. (Centers for Disease Control and Prevention)
- Diabetes when combined with other risk factors, such as cirrhosis or chronic hepatitis.
- Schistosomiasis infection (a parasitic worm), prevalent in Africa, Southeast Asia, South America and the Middle East.
- Birth control pills used to be a risk factor in the past due to their high hormonal doses. Today, with lower hormonal doses prescribed the risk is much lower.
- Occupational exposure to toxic substances such as:
- Vinyl chloride, used in the plastics industry to make PVC. This chemical is used to manufacture plastics that are used in a variety of areas of everyday life, from construction to plastic toys and even to medical devices.
- Arsenic in drinking water has also been associated with a higher risk. There are many countries where industrialization produces contamination of the water with arsenic. In Canada, arsenic levels in drinkable water are capped to 10 micrograms per litre.
- Trichloroethylene, used to remove grease from metals.
- Polychlorinated biphenyls or PCBs, when they are released into the water or leech out of landfills