How obesity affects liver cancer

James Cook University 2014–2017

An individual’s risk of liver cancer increases if they are overweight. Dr Lionel Hebbard and his team conducted a long-range study that aimed to quantify the exact impact of metabolic drivers, particularly obesity, on liver cancer prognosis and progression in patients.

Background

Cancer that starts in the liver is relatively rare, but in Australia the rates are rising steeply. In the last two decades, the incidence rate of liver cancer has increased threefold. Survival rates have improved very little over the same period. In Australia, a person diagnosed with liver cancer today has only a 17% chance of surviving for five years or longer.

Added to this picture, it is estimated that at least a third of future liver cancer cases will be due to fatty liver disease, but how obesity and a fatty liver promote cancer growth is unknown. Dr Hebbard and his team suspected that reduced production of a fat-derived hormone (adiponectin) and increased consumption of fructose (sugar from fruit and corn syrup) could be to blame.

The research

Dr Hebbard and his team investigated the role of hormones and sugars in the development and progression of liver cancer to identify new and better ways to prevent and treat liver cancer.
In the laboratory, the team tested a combination of two anti-cancer drugs, rapamycin and dasatinib, on liver tumours. They found that these two drugs used together are much more effective at restricting cancer growth than each drug on its own. Importantly, they found this combination could shrink tumour size by as much as 80%.

In other experiments, the team discovered that fructose promotes the growth of liver cancer and can make it even more aggressive. They also found that when a particular growth hormone is absent from the liver, fructose has the ability to stop tumour growth. Together, these findings show that fructose has the ability to regulate liver tumour growth.

The impact

Dr Hebbard and his team have increased scientific knowledge about the role of obesity, and particularly fructose, in tumour growth. The team have identified a number of genes they hope to target in future studies.

The team hope their work will result in the development of new targeted treatments that will be effective in treating liver cancer.