Changes in incidence trends of meningioma in Finland, 1990-2017: analysis of Finnish Cancer Registry data.

Background: Meningiomas are the most common primary neoplasm of the central nervous system. Previous research on the incidence of meningioma in Finland showed an increase in the age-standardized incidence rate over three decades (1968-1997). In this study, we analysed meningioma incidence in Finland during 1990-2017.

Materials And Methods: Data on 9842 meningioma patients were obtained from the Finnish Cancer Registry, and population size by calendar year, sex, and age group from Statistics Finland. The European Standard Population was used to calculate age-standardized incidence rates. Poisson regression was used to evaluate differences by sex and age, and joinpoint regression to examine changes in trend.

Results: At the beginning of the study period, the age-standardized incidence of meningioma for men was 2.35/100,000 and for women 6.96/100,000. In the end, it was 4.09/100,000 and 10.19/100,000, respectively. The annual percent change (APC) for women was +4.6 (95% confidence interval, CI 3.10 to 6.20) from 1990 to 2001 and -1.0 (95% CI -1.70 to -0.30) from 2001 to 2017. For men, the APC was +3.1 (95% CI 0.80-5.40) during 1990-2002 and -0.9 (95% CI -2.10 to 0.30) in 2002-2017. The incidence of meningioma in women was 2.8 times higher than in men (rate ratio 2.81; 95% CI 2.68-2.94).

Conclusions: Meningioma incidence increased in both sexes from 1990, but the trend reversed in 2001-2002. Medical imaging or risk factors do not appear to explain the changes.