A study of over 75,000 people has found that moderate-to-severe traumatic brain injury (TBI) is linked with a higher risk of developing malignant brain tumours.
Researchers analysed data from 2000 to 2024 and found that 0.6 per cent of patients with significant TBIs – injuries caused by external force to the brain – developed tumours within three to five years of their injury.
This figure was higher than in people without a history of TBI. By contrast, mild injuries such as concussions did not increase tumour risk.
The research was led by investigators at Mass General Brigham with collaborators from Northwestern University in Chicago, the University of California, San Francisco, the University of Texas Health Science Center, and the University of Missouri.
“I see these results as alarming,” said co-senior author Dr Saef Izzy, a neurologist and head of the immunology of CNS injury programme at Brigham and Women’s Hospital.
“Our work over the past five years has shown that TBI is a chronic condition with lasting effects.
Now, evidence of a potential increased risk of malignant brain tumours adds urgency to shift the focus from short-term recovery to lifelong vigilance.
“Alongside our earlier findings linking TBI and cardiovascular disease, this underscores the importance of long-term monitoring for anyone with a history of TBI.”
The team categorised injuries as mild, moderate or severe, with participants having suffered incidents including car accidents and falls.
Among those with moderate and severe TBIs, 87 out of 14,944 developed tumours within three to five years.
The researchers stressed that the study shows associations and not cause and effect. Understanding the underlying mechanisms will need further translational research.
Earlier studies of military veterans from the Iraq and Afghanistan wars who had suffered TBI showed increased tumour risk, though studies in civilian populations produced mixed findings.
Using international disease classification codes, the team excluded participants with a history of brain tumours, benign tumours, or risk factors such as radiation exposure.
“While there is an increased risk of tumour from TBI, the overall risk remains low. Still, brain tumour is a devastating disease and often gets detected in later stages,” said lead author Dr Sandro Marini, a neurologist at Mass General Brigham.
“Now, we’ve opened the door to monitor TBI patients more closely.”
Future studies could explore whether tumour risk varies depending on the site of the injury, as well as examining outcomes in people with repeated injuries.
