Cases of primary liver cancer have tripled in the last 30 years according to statistics published today by Cancer Research UK.

In 1975, 865 cases of primary liver cancer were diagnosed in Great Britain but the latest figures for 2006 show that number has risen to 3108.

Secondary or metastatic liver cancer - cancer that has spread to the liver from a primary tumour elsewhere in the body - is a relatively common disease. But primary liver cancer- when cancer originates in the liver - has been rare in the UK until recently.

Experts attribute this rise to three things: the increase in alcohol consumption, obesity and hepatitis C. Each of these factors can lead to cirrhosis which in turn may develop into primary liver cancer.

Matt Seymour, Cancer Research UK's professor of gastrointestinal cancer medicine at the University of Leeds said: "Three main risk factors for liver cirrhosis - alcohol, obesity and hepatitis C infection - are getting more common in the UK. So we are seeing more patients with cirrhosis and, in turn, more patients with primary liver cancer.

"This is likely to continue. There is a long delay between exposure to the risk factors and the onset of cancer. It might take between 20 and 40 years for liver cancer to develop after infection with hepatitis C. So even if new cases of infection stopped, the number of cases of cancer would continue to rise for some years."

Hepatitis C is a virus spread by blood to blood contact. In the 1960s and 1980s the virus could have been contracted from the medical use of contaminated blood products but this no longer happens because measures have been put in place to ensure all blood products are completely safe. Today the virus is commonly spread among intravenous drug users.

Another virus, Hepatitis B, is responsible for a small percentage of primary liver cancer in the UK but is a more common cause of primary liver cancer worldwide.

Cancer Research UK is supporting a number of research projects including clinical trials to improve the treatment of primary liver cancer.

Dr Lesley Walker, Cancer Research UK's director of cancer information, said: "While this increase is a concern, it is important for people to understand how their risk of liver cancer can be reduced by changes to lifestyle.

"Cutting down on alcohol and watching your weight will help to reduce the risk of a wide range of cancers including primary liver cancer. Taking plenty of exercise and eating a balanced diet high in fibre, fruit and vegetables and low in fatty foods, red and processed meat can all help towards keeping a healthy weight."