Incidence of vestibular schwannoma in Finland, 1990-2017

Background: An increasing trend in incidence of vestibular schwannomas (VS) has been reported, though not consistently, across populations. Materials and methods: We obtained data from the Finnish Cancer Registry on 1,149 VS cases diagnosed in 1990-2017 with tabular data up to 2022. We calculated age-standardised incidence rates (ASR) overall, by sex, and for 10-year age groups. We analysed time trends using Poisson and joinpoint regression. Results: The average ASR of VS in Finland during 1990-2017 was 8.6/1,000,000 person-years for women and 7.5/1,000,000 for men. A declining trend was found with an average annual percent change of -1.7% (95% confidence interval [CI]: -2.8%, -0.6%) for women, -2.2% (95% CI: -3.6%, -0.7%) for men, and -1.9% (95% CI: -2.9%, -1.0%) for both sexes combined. The ASR in women was 11.6/1,000,000 person-years in 1990 and it decreased to 8.2/1,000,000 by 2017. Correspondingly, the incidence in men was 7.1/1,000,000 in 1990 and decreased to 5.1/1,000,000 by 2017. Some decline in incidence over time was found in all age groups below 80 years, but the decline (2.3-3.1% per year) was statistically significant only in age groups 40-49, 50-59, and 60-69 years. In the oldest age group (80+ years), the incidence of VS increased by 16% per year. For 2018-2022, the ASR was 7.6/1,000,000 for both sexes combined, with a decline by -1.7% (95% CI: -2.3%, -1.2%) annually for the entire period 1990-2022. Conclusion: In contrast to the increasing incidence reported in some studies, we found a decreasing trend in VS incidence for both sexes in Finland.