Head injury and brain tumours in adults: A case–control study in Rio de Janeiro, Brazil Gina Torres Rego Monteiro a, *, Rosa ˆ ngela Alves Pereira b , Rosalina Jorge Koifman a , Se ´rgio Koifman a a Department of Epidemiology, National School of Public Health, FIOCRUZ, Oswaldo Cruz Foundation, Rua Leopoldo Bulho ˜es, 1480 sala 812, Manguinhos, CEP: 21.041-210, Rio de Janeiro, Brazil b Institute of Nutrition, Federal University in Rio de Janeiro, Rio de Janeiro, Brazil ARTICLE INFO Article history: Received 9 September 2005 Received in revised form 4 November 2005 Accepted 14 November 2005 Available online 6 March 2006 Keywords: Brain cancer Glioma Meningioma Case–control study Head injury Risk factor ABSTRACT 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 var- ious 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 asso- ciation 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. Ó 2006 Elsevier Ltd. All rights reserved. 1. Introduction The mortality and incidence rates of central nervous system (CNS) tumours have increased in recent decades in Brazil and worldwide. 1–4 Moreover, brain cancer age-adjusted mor- tality rates in 1980–1998 showed a 50% increase in Brazil, with an especially marked increment in women and the elderly. 5 Various risk factors have been reported to be possibly associ- ated with this increase, such as exposure to certain chemicals (N-nitroso compounds, pesticides, petroleum derivatives, sol- vents, and vinyl chloride), radiation, anti-convulsive drugs, and prior head injury. 6–8 The association between head injury and brain tumours has been a matter of controversy for decades, since Cushing and Eisenhardt (1938) reported that one-third of their brain tu- mour patients presented a history of head injury. Some studies observed that a head injury had occurred years before the tu- mour diagnosis. 9–11 Preston-Martin and colleagues 9 show case reports with convincing circumstantial evidence of prior head injury (e.g., scar or fracture mark on the tumour site) in 8% of a meningioma case series. Case–control studies have reported excess risk meningioma among individuals with any history of severe head injury, such as boxers. 8–10,12 Epidemiological evidence of the association between head injury and brain tu- mour is strongest for meningiomas, even considering positive associations reported for gliomas. 10,12–14 However, other stud- ies have failed to show a statistically significant association between prior head injury and brain cancer. 15 0959-8049/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.ejca.2005.11.028 * Corresponding author: Tel.: +5521 2598 2617; fax: +5521 2270 6772. E-mail address: gtorres@cremerj.com.br (G.T.R. Monteiro). EUROPEAN JOURNAL OF CANCER 42 (2006) 917 – 921 available at www.sciencedirect.com journal homepage: www.ejconline.com