Our ageing immune system could have more to do with our chances of getting cancer than genetic factors, a Dundee University study has claimed.

Eight million people die of cancer across the world each year.

For decades, it has been known that mutations arising, either as a result of genetic conditions or lifestyle and environmental factors, cause cancer.

Researchers looked at data on two million cases of cancer over the 18-70 age range.

They then developed a mathematical equation for how they would expect cancer incidence to rise in relation to a declining immune system and compared it to the age profiles for 100 different cancers.

The study, published in Proceedings of the National Academy of Sciences, suggests the immune system, particularly as it declines, may play a far bigger role in the development of cancer than previously thought.

Senior author Dr Thea Newman said: "This is still very early days but if we are proven right then you could be talking about a whole new way to treat and prevent cancer.

"Nearly all of the mainstream research into cancer is based on how we can understand genetic mutations, target them and thereby cure the disease.

"We're not debating the fact that mutations cause cancer, but are asking whether mutations alone can account for the rapid rise in cancer incidence with age when ageing causes other profound changes in the body."