Genetic mutations linked with leukaemia are “almost inevitable” as people get older, new research suggests.
A study by scientists at the Wellcome Trust Sanger Institute found more than 70% of people over 90 had blood cells with the same DNA alterations found in the cancer, often associated with children.
The results prompted one researcher to warn some people could be “on a journey towards leukaemia” and any rise in life expectancy could see more cases across the country.
Dr George Vassiliou, senior author from the Sanger Institute and Cambridge University Hospitals NHS Trust, said: “These mutations will be harmless for the majority of people but for a few unlucky carriers they will take the body on a journey towards leukaemia.”
Dr Vassiliou also told the BBC News website:“We had suspected people had these mutations, but didn’t expect they would be an almost inevitable consequence of ageing.
“There is one warning for the future, if there was a significant extension of life expectancy then there could be a significant increase in leukaemia.
“We don’t know what percentage of people would go on to develop leukaemia, it might be one in 1,000 or even one in 100 or more and that would have a dramatic impact.”
The study, published in the Cell Reports journal, analysed 4,219 people without any evidence of blood cancer using what scientists called ultra-deep sequencing method to detect DNA changes.
Up to 20% of people aged between 50 and 60 also had genetic defects associated with leukaemia but none was found with the most common mutation indicating the disease.
Dr Thomas McKerrell, joint author of the study, said: “Leukaemia results from the gradual accumulation of DNA mutations in blood stem cells, in a process that can take decades.
“Over time, the probability of these cells acquiring mutations rises. What surprised us was that we found these mutations in such a large proportion of elderly people.
“This study helps us understand how ageing can lead to leukaemia, even though the great majority of people will not live long enough to accumulate all the mutations required to develop the disease.”