How diet, nutrition and physical activity affect liver cancer risk. In total, we analysed 34 studies from around the world; this comprises over 8 million people and 24,600 cases of liver cancer.
The liver is the body’s largest internal organ. It processes and stores nutrients and produces cholesterol and proteins such as albumin, clotting factors and the lipoproteins that carry cholesterol. It also secretes bile and performs many metabolic functions, including detoxification of several classes of carcinogens.
Our Expert Panel has reviewed the evidence on diet, weight, physical activity and the risk of liver cancer.
There is strong evidence that:
There is some evidence that:
In addition to the findings on diet, nutrition and physical activity outlined above, other established causes of liver cancer include:
Cirrhosis of the liver increases the risk of liver cancer, and so can be seen as a cause of this cancer.
Chronic viral hepatitis is a cause of liver cancer. Infestation of liver flukes is a cause of cholangiocarcinoma.
Long-term use of oral contraceptives containing high doses of oestrogen and progesterone increase the risk of this cancer.
Smoking increases the risk of liver cancer. In smokers who also have hepatitis B or hepatitis C virus infection, the risk is increased further, and those who smoke as well as consume large amounts of alcohol may also be at increased risk compared with those who do not smoke or drink.
Patients with cirrhosis (scarring of the liver due to previous damage) have the highest risk of developing hepatocellular carcinoma: approximately 90–95% of people who develop hepatocellular carcinoma have underlying cirrhosis. So any cause of cirrhosis, either viral or chemical, is likely to increase cancer risk. The liver is also a common site for metastasis of tumours originating in other organs.
As for cancers at most sites, accumulated sequential changes, specifically in mature hepatocytes, lead to the development of dysplastic nodules; over the course of around five years, 30% may develop into tumours . Hepatocellular carcinoma cells show numerous genetic changes, perhaps accumulated during cellular proliferation, which is part of the normal liver repair process. The hepatitis B virus related type appears to be more genetically unstable than others and acts by directly damaging cells and their DNA, whereas hepatitis C virus shows more of an indirect effect, mediated by cirrhosis.
Full references and a summary of the mechanisms underpinning all the findings can be found in the liver cancer report.
In 2018, World Cancer Research Fund International published Diet, Nutrition, Physical Activity and Cancer: a Global Perspective on behalf of AICR, WCRF and WKOF. This was the third in our series of major reports looking at the many ways in which our diets, and how active we are, affect our cancer risk. You can find out much more about liver cancer by downloading a pdf of the relevant chapter in the 2018 report. Please note, however, that this webpage may have been updated since the report was published.