A new study shows that people who suffer from a traumatic brain injury are almost five times more likely to be diagnosed with a malignant brain tumor than those without a brain injury. These tumors developed within three years of the injury, and are related to the severity of injury.
The idea of traumatic brain injury as a risk factor for brain tumors is a controversial one. There is some evidence that the site of the injury is more likely to be associated with a future brain tumor, however, the research is mixed and inconclusive. Other possible reasons for the increased risk of brain cancer are increased exposure to radiation through CT scans and the possibility that very new brain tumor cells increase the risk of falls or other accidents that result in brain injury.
Chen Y-H, Keller JJ, Kang J-H, & Lin H-C. Association between traumatic brain injury and the subsequent risk of brain cancer. Journal of Neurotrauma. (May 2012).