Real Incidence of Vestibular Schwannoma? Estimations From a National Registry.

OBJECTIVE: To identify incidence of vestibular schwannoma (VS) in The Netherlands. Determining incidence of VS poses considerable challenges given the lack of complete epidemiologic data. STUDY
DESIGN: Retrospective patient review.
SETTING: Tertiary referral center. PATIENTS: Patients with VS in The Netherlands. Data on patients with VS during 2001 to 2012 were obtained from The Netherlands Cancer Registry (NCR). Notification to the NCR is primarily pathology-based, but additional sources are used, including databases from hospital registrations and radiology departments. In addition, VS incidence estimations for the Leiden region were made; since these data are considered most complete, it was anticipated that estimates calculated from this region approximated the true incidence of VS in The Netherlands. INTERVENTION(S): Magnetic resonance imaging (MRI). MAIN OUTCOME MEASURE(S): Incidence of VS.
RESULTS: From 2001 to 2012, a total of 3,663 patients of VS were registered. One thousand forty patients (28.4%) were pathologically confirmed, the majority only had a clinical diagnosis (n = 2623, 71.6%). Incidence increased from 10.3 per one million inhabitants (European Standardized Rate, ESR) to 15.5. Considerable variation in incidence rates was observed across regions, ranging from 12.0 to 24.9 per million over the total period. In the Leiden region, incidence was estimated at 25.5 per million during 2005 to 2007, and 33.2 per million during 2009 to 2012. In this region, the ratio of clinical versus histopathological diagnoses rose from 1.4 to 6.7.
CONCLUSIONS: Completeness of the registration of VS varies across regions in The Netherlands. Incidence estimates obtained from regions with the highest rates are higher than those reported by previous studies.