Incidences of gliomas and meningiomas in Denmark, 1943 to 1997

OBJECTIVE: The objective of this study was to determine the nationwide, population based incidences of intracranial gliomas and meningiomas (of all grades) during 55 years of monitoring in Denmark. METHODS: On the basis of reports in the Danish Cancer Registry, we calculated age-standardized, period-specific incidences and age- and birth cohort-specific incidences, in 5-year age and calendar intervals, for intracranial gliomas and meningiomas. RESULTS: The incidence of gliomas increased 1.7-fold from 1943 to 1947 to 1993 to 1997, whereas the incidence for meningiomas increased 3.9-fold during the same period. CONCLUSION: Based on complete notification to the Danish Cancer Registry, the overall incidences of intracranial gliomas and meningiomas increased during a 55 year period. These increases were observed for all age groups and both sexes. These increases could be explained on the basis of improved diagnoses of these tumors. For gliomas, a maximal annual incidence of approximately 4 cases/100,000 population (World Standard Population) was observed in Denmark at the end of the study period, suggesting that the effects of improved diagnostic tools have reached their maximum with respect to this tumor type. The same was not observed for the incidence of meningiomas, suggesting that perhaps underreporting is still present.