Head trauma and subsequent brain tumors.

A long term study of 2,953 persons with 29,859 person-years of follow-up after head injury provided an opportunity to investigate the long-debated association between head trauma and subsequent intracranial tumor. In this series the observed number of cases of subsequent brain tumor did not differ from the number we expected. Because brain tumors are relatively rare, the results of this large series cannot absolutely refute the possibility that head trauma predisposes to brain tumor, but the individual risk is very small, and the weight of evidence does not support an etiological association. The occurrence of subsequent brain tumors in this series was not associated with the severity or location of the head injury. Head trauma does not seem to be a significant etiological factor in meningioma; that tumor has a higher incidence in females, whereas males have 2- to 3-fold greater incidence of head trauma. If any association between head trauma and subsequent brain tumor does exist, it is extremely small or occurs only in the presence of other factors, which themselves must be rare.