Head injury and brain tumours in adults: A case-control study in Rio de Janeiro, Brazil.

A hospital-based case-control study exploring the association between selected risk factors and head injury in adults, brain trauma included, was carried out in Greater Metropolitan Rio de Janeiro, Brazil. Cases included adults diagnosed with primary brain tumours (n = 231). Controls were matched for gender and age among in-patients hospitalized for various conditions unrelated to brain cancer (n = 261) identified in the same hospitals where cases were enrolled. Risk of having experienced head injury was more frequent among cases (46%) than controls (36%) (OR(adj) = 1.49; 95% CI = 1.03-2.15). A dose-response effect was observed according to the number of head injuries, and a statistically borderline association was observed for meningioma (OR(adj) = 1.63; 95% CI = 0.96-2.75). Although recall bias cannot be ruled out, our results suggest an association between prior head injury and the development of brain tumours in adults.