Over the last 35 years liver cancer has had the second highest percentage change in incidence rate of all cancers with an increase of over 300%. According to the an AIHW report on Cancer in Australia 2017, an estimated 1 in 190 Australians under the age of 75 years are affected by liver cancer, with incidence rate increasing with age to 1 in 113 Australians estimated to be affected over the age of 85 years. Additionally, men are approximately 3 times more likely to develop liver cancer compared to women.
Furthermore, liver cancer has maintained a very low rate of 5-year relative survival at approximately only 17%. It is currently the 6th most common cause of death by cancer in men, and ninth in women. In fact, liver cancers also have the second greatest estimated percentage increase in mortality rate out of all cancers and has continued to see an upward trend since the 1980's (from 2.3 to 6.8 per 100,000). In 2014, mortality due to liver cancer was 1,732 people, and the projected numbers for 2017 and 2018 are estimated at 1,979 and 2,088 people respectively.
Table available in the AIHW report on Cancer in Australia 2017.
What's causing this increase in liver cancer?
It is estimated that approximately 71% of liver cancer cases globally are caused by chronic infections with hepatitis B virus (HBV) or hepatitis C virus (HCV). Roughly 450,000 Australians currently live with either hepatitis B or hepatitis C, and chronic infection is highly associated with infection and inflammation of the liver as well as cirrhosis, which can lead to liver cancer.
The rise in liver cancer incidence is particularly high amongst those born between 1945 and 1965 and is likely linked to the prevalence of HCV infection which was very high during the 1960's to 1980's before hepatitis was discovered to be transmitted through contaminated blood transfusions and injected drug use.
Smoking, high alcohol consumption and obesity are also all factors that are linked to liver cancer. Although smoking rates are now falling amongst Australians, there remains a time gap between when people smoked and a cancer diagnosis. A similar situation is apparent with alcohol consumption. This may contribute to the reason why liver cancer is more common in older people, as the damage caused by lifestyle habits when smoking and drinking habits were higher is only now becoming apparent. However, the declining rates of smoking and drinking suggest that hopefully there will be less of a contribution to liver cancer cases from these factors in the future.
On the other hand, as obesity rate increases there is also a rise in cases of diabetes and non-alcoholic fatty liver disease (NAFLD) where obesity is one of the main risk factors. Both diabetes and NAFLD are risk factors for developing liver cancer thus if these conditions continue to rise it is likely that so will the incidence of liver cancer.
Reducing the rate of liver cancer
A vaccine against HBV has been available since 1982, with Australia's hepatitis B vaccination programme commencing in 1988. A number of preventative interventions are also in place to tackle the issue of HCV infection as well as new strategies for screening and treatment. These vaccination and health monitoring programmes are the best prevention strategies to reduce incidence of liver cancer, followed by lifestyle changes to encourage health living.
Resources:
Cancer in Australia 2017
Cancer Council Australia – Causes of liver cancer
Hepatitis C strategy 2014-2017
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