Incidence of Vestibular Schwannoma over the Past Half-Century: A Population-Based Study of Olmsted County, Minnesota

Abstract

Objective The absence of a centralized health system has limited epidemiologic research surrounding vestibular schwannoma (VS) in the United States. The Rochester Epidemiology Project (REP) comprises a unique medical consortium that covers a complete population of all ages in a well-defined geographic region over the past half-century. The objective of this study was to characterize the incidence of sporadic VS over this extended period. Study Design Population-based study. Setting Olmsted County, Minnesota. Subjects and Methods Review of all VSs diagnosed between January 1, 1966, and December 31, 2016, was conducted with the REP medical records linkage system. Results A total of 153 incident cases of VS were identified. The incidence of VS significantly increased over the past half-century from 1.5 per 100,000 person-years during the first decade to 4.2 in the last decade ( P < .001). Incidence increased with age ( P < .001): those aged ≥70 years exhibited the highest incidence rate at 18.3 per 100,000 person-years in the last decade. Age at diagnosis significantly increased from a median of 52 years in the first decade to 62 years in the last ( P < .001). Despite presenting with fewer symptoms and smaller tumors, the time delay between symptom onset and diagnosis significantly decreased over the past 5 decades (all P < .05). Almost 1 in 4 patients was diagnosed incidentally in the last decade. Conclusion The incidence of VS increased significantly over the past half-century to a rate greater than previously reported. Patients' ease of access to medical care in Olmsted County and the comprehensive REP system likely contributed to this elevated detection rate of VS.

Keywords: Olmsted County; Rochester epidemiology project; acoustic neuroma; epidemiology; incidence; incidental; sporadic; vestibular schwannoma.

Figure 1.

Incidence of sporadic vestibular schwannoma from 1966–2016 in Olmsted County, Minnesota by year of diagnosis.

Figure 2.

Incidence of sporadic vestibular schwannoma in Olmsted County, Minnesota by age at diagnosis (a) from 1966 through 2016 and (b) from 2006 through 2016.

Figure 2.

Incidence of sporadic vestibular schwannoma in Olmsted County, Minnesota by age at diagnosis (a) from 1966 through 2016 and (b) from 2006 through 2016.