Around 25 per cent of the risk of developing the most common type of brain cancer, known as glioma, comes from inherited DNA errors, new research shows.
The study is the first to demonstrate unequivocally that the risk of developing glioma is dependent on many different genes all exerting a small effect.
Researchers from The Institute of Cancer Research, London, working alongside scientists in France, Germany and the US, compared data from 3,374 patients with glioma and 4,571 without cancer.
Using powerful statistical analysis, they were able to deduce the contributation of all common inherited genetic variants on the risk of developing glioma. This figure is higher than for many other cancers.
The research, published in Scientific Reports, found that genetic mutations currently linked to gliomas only account for six per cent of a person’s risk of developing the disease – indicating that there are much more influential, rare mutations that have yet to be found by genetic studies.
The study was funded by the Sir John Fisher Foundation, the DJ Fielding Medical Research Trust, the Wellcome Trust and Cancer Research UK.
Gliomas account for around 40 per cent of all brain tumours and are often associated with a poor prognosis for the patient. Understanding more about the causes of glioma could allow doctors to monitor those most at risk and diagnose the disease earlier, at a stage when it may be easier to treat.
Other contributing factors to the development of gliomas, such as possible environmental influences, have yet to be identified – but could account for up to 75 per cent of the risk of the disease.
The study showed that glioma occurs through a combination of numerous common genetic variants that in isolation slightly increase the risk of disease, plus a smaller number of rare mutations that carry far greater risk.
The researchers suggest that larger studies will need to be conducted in future to identify these ‘hidden’ genetic mutations that are important influencers in driving gliomas.
Study leader Professor Richard Houlston, Professor of Molecular and Population Genetics at The Institute of Cancer Research, London, said: “We have studied the genomes of a large number of people with glioma and compared them to people without cancer. Using powerful statistical analysis we were able to show that inherited genetic factors make a significant contribution to the risk of developing this major type of brain cancer.
“We found that the genes we currently know about only contribute a small amount to the risk of developing these brain tumours, providing a strong rationale for continuing work to unlock the mysteries of a cancer that is currently poorly understood.
“Glioma is often very difficult to treat. We hope understanding more about its origins will help us identify those most at risk in future and help us develop new treatments.”