Adult blood cancer mutations can begin in early childhood, Wellcome Sanger Institute and University of Cambridge research finds
The study shows how the mutations proliferate in the body over decades before cancer symptoms appear later in life.
Further work is now needed to understand whether this information could be used to aid earlier detection or treatment.
More than 40,000 people are diagnosed with blood cancer in the UK every year, making it the fifth most common cancer. About 15,000 of them die from it, making it the third biggest cancer killer.
There are more than 100 different types of blood cancer and the risk of it increases with age. Nearly 40 per cent of those diagnosed with it are aged 75 or over.
The new study, published in Nature, suggests the mutations cause blood cells to multiply at varying rates in different people.
Cancer symptoms appear earlier in those people for whom the mutations cause faster growth, the research suggests.
If the mutations proliferate slowly, however, cancer symptoms may never appear or only come to light following a death by other causes.
The scientists used whole genome sequencing technology of more than 1,000 blood cell clones from patients and in-depth genetic analysis of bone marrow and blood samples to establish the family history of individual blood cancers.
That enabled an accurate estimate of when the cancer-causing mutations occurred in a patient’s lifetime.
Ten people aged between 20 and 75 with Philadelphia-negative myeloproliferative neoplasms − a type of cancer that causes stem cells in the bone marrow to produce too many blood cells - were studied.
The most common of the multiple mutations linked to this blood cancer is known as JAK2V617F.
They found that, in these 10 patients, the first cancer-linked mutations emerged as early as a few weeks after conception and up to age 12, although cancer symptoms only presented decades later in life.
They then estimated how long over a patient’s lifetime it took for these mutated cells to multiply to the point where cancer symptoms became visible.
Prof Peter Campbell, senior author on the study from the Wellcome Sanger Institute, said: “JAK2V617F is an established cancer causing mutation for blood cancer, and for the first time our research has allowed us to trace when these mutations occurred in this specific type of blood cancer. Further research is now needed to see how this new information could help detect cancers sooner and if there are any existing or new therapies that could help treat the disease earlier.”
The findings suggest that some blood cancers are a lifelong process that begins with a single cell acquiring a cancer-linked mutation early in life which slowly grows over decades.
Dr Jyoti Nangalia, a senior author on the study from the Wellcome Sanger Institute and Wellcome-MRC Cambridge Stem Cell Institute, said: “Our research shows that cancer-driving mutations can occur in early childhood, even in the womb, to result in cancer diagnosis decades later. This is not something we were expecting.
“Blood cancer impacts thousands of lives every day and research such as ours into the timing and pace of how different cancers develop is crucial if we are going to find new ways to prevent these conditions. The success of our approach for tracking the origin and growth of this blood cancer could be applied to many other cancers and diseases.”
Dr Nicholas Williams, first author from the Wellcome Sanger Institute, said: “By using whole genome sequencing and analysis of the pattern of sharing of mutations between blood cells, we were able to create family trees of these cells enabling us to identify when in life these shared mutations arose.
“This in-depth process has given us new insight into the development of blood cancer and will allow us to hopefully track the development of other blood cancers in the future.”