AN INTERNATIONAL CASE-CONTROL STUDY OF ADULT GLIOMA AND MENINGIOMA - THE ROLE OF HEAD TRAUMA

Background Increased brain tumour risk after head trauma suggested by case reports and clinical series has been previously studied epidemiol ogically with mixed results. An international multicentre case-control study investigated the role of head trauma from injury or sports part icipation in adult brain tumour risk. Methods In all, 1178 glioma and 330 meningioma cases were individually or frequency matched to 2236 co ntrols. Only exposures that occurred at least 5 years before diagnosis and head injuries that received medical attention were considered. Re sults Risk for ever having experienced a head injury was highest for m ale meningiomas (odds ratio [OR] = 1.5, 95% confidence interval [CI] : 0.9-2.6) but was lower for 'serious' injuries, i.e. those causing los s of consciousness, loss of memory or hospitalization (OR = 1.2, 95% C I: 0.6-2.3). Among male meningiomas, latency of 15 to 24 years signifi cantly increased risk (OR = 5.4, 95% CI: 1.7-16.6), and risk was eleva ted among those who participated in sports most correlated with head i njury (OR = 1.9, 95% CI : 0.7-5.3). Odds ratios were lower for male gl iomas (OR = 1.2, 95% CI : 0.9-1.5 for any injury; OR = 1.1, 95% CI : 0 .7-1.6 for serious injuries) and in females in general. Conclusions Ev idence for elevated brain tumour risk after head trauma was strongest for meningiomas in men. Findings related to sports should be interpret ed cautiously due to cultural variability in our data and our lack of complete data on physical exercise in general which appeared to be pro tective.