A study found that people who suffered brain injuries from traffic accidents, falls, and other causes are at a higher risk of developing malignant brain tumors in the future. The researchers emphasized that, since malignant brain tumors are often found at advanced stages, it is important to monitor individuals who have experienced brain injuries closely over the long term.
A research team from Harvard University's Massachusetts General Hospital and Brigham and Women's Hospital analyzed the correlation between traumatic brain injury (TBI) and the risk of malignant brain tumor occurrence, concluding that the more severe the brain damage, the higher the likelihood of developing brain tumors. The findings were published on the 25th in the American Medical Association (AMA)'s international journal "JAMA Network Open."
Traumatic brain injury is divided into primary damage and secondary damage. Primary damage is the direct injury to brain tissue, while secondary damage leads to issues like blood-brain barrier dysfunction, brain swelling, ischemia caused by insufficient blood supply to tissues or organs, and intracranial hypertension.
The researchers tracked 75,000 patients who experienced brain injuries from 2000 to 2024, comparing them with an equal number of controls from the general population. The results showed that mild concussions were not associated with brain tumor occurrence, but patients with moderate to severe brain injuries exhibited a significantly increased risk of malignant brain tumors. In fact, among 14,944 moderate to severe patients, 87 (0.6%) had malignant brain tumors confirmed within 3 to 5 years after the injury.
Saef Izzy, a professor of neurology at Brigham and Women's Hospital who led the study, noted, "Traumatic brain injury is clearly not just a problem of short-term recovery, but a chronic condition that needs to be managed over the long term. Following previous research confirming that TBI patients have a higher risk of cardiovascular diseases, this study has also verified the risk of malignant brain tumors, highlighting the need for lifelong monitoring."
Research findings have suggested for some time that TBI can influence the occurrence of various brain diseases. A study from the University of Birmingham in the UK found that the incidence of strokes was 86% higher among those who experienced TBI, with the risk lasting up to 5 years. Research from the University of Pennsylvania in the U.S. showed that individuals with TBI had nearly double the mortality rate from cancer, cardiovascular diseases, and neurological disorders compared to those without such experiences.
The researchers analyzed TBI by classifying it as mild, moderate, or severe, with causes of injury ranging from traffic accidents to falls. Patients with a prior history of brain tumors, radiation exposure, or benign tumors were all excluded. Previous studies reported an increased risk of brain tumors associated with TBI among military veterans, but results have been inconsistent in civilian studies. This study is a large-scale analysis that observed 75,000 individuals over 24 years.
The research team plans to confirm the correlation between the area of brain damage and the area of tumor occurrence through future imaging studies, and additional analyses on patient groups experiencing repeated injuries are also in preparation. Experts advise that individuals who have experienced brain injuries require regular brain health check-ups and long-term monitoring even after short-term recovery.
Sandro Marini, a neurologist at Massachusetts General Hospital who participated in the study, said, "Statistically, the risk has increased, but overall, the occurrence of brain tumors remains rare. Nevertheless, since malignant brain tumors are usually found at advanced stages, it is essential to monitor patients who have sustained brain injuries closely over the long term."
References
JAMA Network Open (2025), DOI: https://doi.org/10.1001/jamanetworkopen.2025.28850