Objective: Reports on the epidemiology of vestibular schwannoma (VS) indicate an increase in diagnosed cases, often based on selected materials over a limited period of time. This report presents prospective 40-year epidemiological data from an unselected national cohort of all patients diagnosed with a VS in Denmark since 1976. Study-design: Data on gender, age, tumor localization and size registered during the period 1976–2015 were retrieved. Results: 3637 new cases of VS were diagnosed during the 40-year period. The annual number of diagnosed VS increased from 14 in 1976 to 193 in 2015. Mean extrameatal tumor size decreased from 26mm in 1976 to 13.4mm in 2015. Large and giant tumors were more frequent during the first decades, whereas predominantly smaller tumors were diagnosed during the recent years. Median age at diagnosis increased gradually from 49.2 years in 1976 to 60 years in 2015. Conclusion: Over the past 40 years, the incidence rate of vestibular schwannomas has increased steadily from 3 VS/million/year to 34 VS/million/year, primarily due to easier access to improved diagnostics and the finding of more tumors in older people. Concurrently, the diagnostic tumor size has decreased from 26mm to 7mm, and the age at diagnosis has increased from 49 to 60 years.

Background: Optimal management of vestibular schwannoma (VS) is still debated and thus international consensus has not been achieved. Treatment options are observation, radiotherapy, and surgery. Knowledge on the natural history of tumor growth is essential for choice of treatment modality. The aim is to present intra-/extrameatal tumor growth and management data from a prospective, unselected national cohort of patients diagnosed with VS during the period 1976–2015. Methods: Since 1976, all data from patients diagnosed with sporadic VS in Denmark have been referred to our national treatment center, where they have been entered prospectively into the national database. Data on tumor localization, growth, and treatment were retrieved. Growth definition: >2 mm by linear measurement, in accordance with the Tokyo 2001 consensus-meeting recommendations. Results: 3637 cases of VS were diagnosed, in which 1304 patients had surgery and 21 received radiotherapy post diagnosis. 2312 patients were observed with mean follow-up of 7.33 years. Of these, 434(19%; 102 intra-and 332 extrameatal tumors) changed to active treatment during the observation period due to tumor growth. 5 years after diagnosis, 21% of the intrameatal tumors exhibited growth during observation, whereas 37% of extrameatal tumors had grown, increasing to 25% intrameatal and 42% extrameatal after 10 years. Following growth, the intrameatal tumors were mostly observed further and the extrameatal mostly underwent surgery. Tumor growth occurred mainly within the first 5 years post diagnosis. Conclusion: This natural history study documents the growth occurrence of both intra-and extrameatal VS during the first 12 years after diagnosis and should be used in patient counseling, management, and treatment decision making.

Objective This is a systematic review of the literature on the spontaneous course of hearing in patients observed with a vestibular schwannoma. Included studies are appraised using the Grading of Recommendations Assessment, Development and Evaluation system. Design PubMed, Embase, Medline, Cochrane library, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) were searched for literature on hearing in patients observed with a vestibular schwannoma. Participants Of 217 evaluated papers, 15 were included, representing a total of 2,142 patients. Main Outcome Measures Hearing according to the AAO-HNS (American Academy of Otorhinolaryngology- Head and Neck Surgery) classification system. Weighted average of the proportion of patients preserving good hearing (>70% discrimination score and pure tone audiometry [PTA] < 30dB) and serviceable hearing (>50% discrimination score and PTA < 50dB) was determined. Results Fifty percent of patients presenting with good hearing at diagnosis had preserved this after a mean of 5 years of observation, whereas serviceable hearing was preserved in 54%. Patients with normal discrimination at diagnosis preserve their hearing very well. Very few studies exist on long-term hearing preservation. Conclusions After 5 years of observation, around half of patients will have preserved good or serviceable hearing. Patients with normal discrimination at diagnosis are more likely to preserve good hearing.