Incidence Of Vestibular Schwannoma Research Articles

Current trends in vestibular schwannoma management at a referral center in Indonesia: A cross-sectional study with retrospective data collection

Background. Vestibular schwannoma (VS) is the most common benign brain tumor of the cerebellopontine angle. Due to its location, this pathology can create both focal and general deficits. The registry system for VS in Indonesia is developing, including in the author’s institution, which eventually shows a changing trend in managing VS. Methods. We retrospectively collected data from all patients diagnosed with vestibular schwannoma, based on histological or radiological results. Treatments included craniotomy and/or Gamma Knife Radiosurgery (GKRS) from 2018 to 2023. Results. Data from 88 patients were analyzed. The number of treated patients has increased annually. VS predominantly affects females (64%). The proportion between GKRS and craniotomy procedures also shifted throughout the year. Common symptoms included hearing loss (63.6%), disequilibrium (50%), and headaches (39.7%). The most common tumor size was medium (15-30 mm; n=37; 42%). Tumors that fell into the intrameatal and small (<15 mm) categories were all treated with GKRS, whereas the other groups were divided into GKRS and craniotomy. GKRS demonstrated high efficacy in tumor control and favorable hearing and facial nerve preservation, whereas craniotomy remained crucial for larger tumors. Conclusion. The number of VS diagnosed each year has increased in our center, accompanied by a noticeable shift in preference from GKRS to craniotomy, which is influenced by the integration of intraoperative monitoring. Treatment preference was further determined based on the clinical profile and tumor size. In the future, there is a need to develop a national registry to better reflect the true incidence of VS within the Indonesian population.

Commentary to 'Incidence of vestibular schwannoma in Finland, 1990-2017' Pediatric vestibular schwannomas: an overlooked epidemiological aspect?

Commentary to 'Incidence of vestibular schwannoma in Finland, 1990-2017' Pediatric vestibular schwannomas: an overlooked epidemiological aspect?

Incidence of vestibular schwannoma in Finland, 1990-2017.

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. 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. In contrast to the increasing incidence reported in some studies, we found a decreasing trend in VS incidence for both sexes in Finland.

Incidence of Vestibular Schwannoma in Patients with Unilateral Tinnitus: A Systematic Review and Meta-Analysis.

Vestibular schwannoma (VS) is a tumor of the vestibulocochlear nerve. Current literature indicates that 1.6% of patients undergoing magnetic resonance imaging of the internal auditory meatus (MRI IAM) for audiovestibular symptoms are diagnosed with a VS. However, there is limited research reporting on patients who present with unilateral tinnitus without asymmetrical hearing loss. This study is a systematic review and meta-analysis evaluating how many of those patients had a VS diagnosed on MRI IAM. Online searches of PubMed, Medline, and Embase databases were performed up to October 2022. This meta-analysis was undertaken aligning with PRISMA guidelines. Articles reporting on patients having MRI IAM for unilateral tinnitus without asymmetrical hearing loss were included. Outcomes measures were patient demographics, VS cases, incidental findings, size, and management of tumor. A meta-analysis of proportions was performed using a random-effects model with the restricted maximum likelihood method. Quality assessment was performed using the Joanna Briggs Institute critical appraisal checklist. Seven case series were included in the review: a total of 1,394 patients. Seven patients had a VS, with a median size of 4 mm. The pooled detection rate for VS was 0.08% (95% confidence interval = 0.00-0.45). Subsequent management was reported in six cases of which four were actively monitored and two surgically excised. The most common incidental finding was sinus disease (49 patients). Our findings indicate that MRI IAM has a low diagnostic yield for VS detection in patients presenting with unilateral tinnitus without asymmetrical hearing loss, with mostly small tumors that are conservatively managed.

Incidence and presentation of vestibular schwannoma: a 3-year cohort registry study.

Vestibular schwannoma (VS) is the most common benign tumour arising in the lateral skull base. Reported incidence rates of VS vary across geographical locations and over time. There is scarce updated evidence over the past decade on the epidemiology and mode of presentation of VS. To describe the epidemiology and mode of presentation of VS in the East of England between 2013 and 2016. A retrospective epidemiological analysis of data from a national VS registry and electronic patient records was conducted, including all newly diagnosed adult patients in a UK tertiary referral centre, between April 1st, 2013, and March 31st, 2016. There were 391 new cases identified resulting in an overall mean incidence of 2.2 VS cases per 100,000 person-year. The incidence rate for all patients in the <40 age group ranged between 0.3 and 0.7 per 100,000 person-year, increasing to a range of 5.7 to 6.1 per 100,000 person-year in the 60-69 age group. The top three combinations of symptoms on presentation per patient were hearing loss and tinnitus (97, 24.8%), hearing loss alone (79, 20.2%) and hearing loss, tinnitus, and balance symptoms (61, 15.6%). The median duration of symptoms was 12 months, with a wide range from 1.4 to 300 months. Age was negatively correlated with tumour size (r = -0.14 [-0.24 to -0.04], p=0.01) and positively correlated with symptom duration (r = 0.16 [0.03-0.29], p=0.02). The incidence of vestibular schwannoma has increased compared to previous studies in the UK and is similar to incidence rates reported in other countries during the past decade. It peaks in the seventh decade of life, mainly because of an increase in the diagnosis of small tumours with a long duration of audio-vestibular symptoms in older patients, compared to earlier studies.

Incidence and Risk Factors of Vestibular Schwannoma in Korea : A Population-Based Study.

This study aims to investigate the incidence of vestibular schwannoma (VS) and demographic characteristics in Korea using population-based National Health Insurance Service data. This study analyzed Korean National Health Insurance Service data from 2005 to 2020, based on the International Classification of Diseases, 10th version, Clinical Modification codes D333 and D431. Only those patients who had undergone magnetic resonance imaging and audiologic tests were considered definitive cases. Demographic variables included age, sex, treatment modality, hypertension, diabetics, dyslipidemia, smoking history, alcohol history, and income status. The total number of VS patients was 5751. The average incidence rate was 0.71 per 100000 from 2005 to 2020, and the annual incidence rate increased from 0.33 in 2005 to 1.32 in 2019 but decreased to 0.80 in 2020. Incidence was highest in those aged 60-69 years (1.791) and lowest in those younger than 20 years (0.041). Incidence was higher in females, and the number of patients who received radiosurgery (46.64%) was largest compared to the wait and scan group (37.96%), microsurgery group (12.85%), or the group who received both (2.56%). Diabetes, dyslipidemia, and alcohol consumption increased the risk of VS, while cigarette smoking reduced the risk of VS. The incidence of VS exhibited an increasing trend from 2005 to 2019. Radiosurgery (46.64%) was the most common treatment modality. Diabetes, dyslipidemia, and alcohol consumption increased the risk of VS, while cigarette smoking reduced the risk of VS.

Vestibular schwannoma – a retrospective study in the Republic of Moldova

Vestibular schwannoma is a benign, intracranial tumor of the 8th pair of cranial nerves. The incidence of vestibular schwannoma is 3-5.2 cases per 100000 people. It re­pre­sents 6% of all intracranial tumors and 80% of tumors located in the cerebellopontine angle. In this paper, the authors present the results of a retrospective study of vestibular schwannoma patients who underwent vestibular schwan­noma surgery between 2010 and 2019.

Transcriptomic Profile Reveals Deregulation of Hearing-Loss Related Genes in Vestibular Schwannoma Cells Following Electromagnetic Field Exposure

Hearing loss (HL) is the most common sensory disorder in the world population. One common cause of HL is the presence of vestibular schwannoma (VS), a benign tumor of the VIII cranial nerve, arising from Schwann cell (SC) transformation. In the last decade, the increasing incidence of VS has been correlated to electromagnetic field (EMF) exposure, which might be considered a pathogenic cause of VS development and HL. Here, we explore the molecular mechanisms underlying the biologic changes of human SCs and/or their oncogenic transformation following EMF exposure. Through NGS technology and RNA-Seq transcriptomic analysis, we investigated the genomic profile and the differential display of HL-related genes after chronic EMF. We found that chronic EMF exposure modified the cell proliferation, in parallel with intracellular signaling and metabolic pathways changes, mostly related to translation and mitochondrial activities. Importantly, the expression of HL-related genes such as NEFL, TPRN, OTOGL, GJB2, and REST appeared to be deregulated in chronic EMF exposure. In conclusion, we suggest that, at a preclinical stage, EMF exposure might promote the transformation of VS cells and contribute to HL.

Case series of vestibular schwannoma patients with no asymmetry in hearing

Objective(1) Describe the presenting symptoms and tumor characteristics of patients who are diagnosed with a vestibular schwannoma (VS) with normal hearing or symmetric hearing loss, and (2) report the prospective growth and treatment of each tumor. MethodsThis is a retrospective cohort study of acoustic neuroma patients who were found to have a VS and normal or symmetric hearing loss at a single tertiary care academic center from 1999 to 2012. Medical records were reviewed collecting the following information: patient demographics, symptoms, MRI characteristics, and treatment modality. Results15/195 (7.7%) patients met criteria for the study. Dizziness was the most common presenting symptom occurring in 9 subjects (60%), followed by headache in 6 (40%), vision changes in 5 (33%), tinnitus in 5 (33%), and unilateral hearing loss in 1 (7%). The average tumor size was 1.07 cm (range 0.3–2.2 cm). Eight (53%) patients presented with intracanalicular tumors. Growth was observed in 6 subjects (40%) with average growth rate in those who exhibited mean growth of 1.8 mm per year. Treatment consisted of surgical removal in 4 cases (27%), gamma knife therapy in 1 (7%), and observation or loss to follow-up in 10 (66%). ConclusionsThe incidence of VS with normal hearing was 7.7% Patients with VSs who do not exhibit unilateral hearing loss present most commonly with dizziness. Most of our patients had small, intracanalicular tumors with the largest tumor measuring 2.2 cm in greatest dimension. Of those who were managed conservatively with repeat imaging and observation, most showed tumor growth.

Underreporting of Vestibular Schwannoma Incidence Within National Brain Tumor and Cancer Registries in the United States.

Reports using large brain tumor and cancer registries suggest that the incidence of vestibular schwannoma is considerably lower in the United States compared with other countries. The current study compares the incidence and disease characteristics of vestibular schwannoma within a large tertiary referral center's brain tumor and cancer registry using nationally mandated reporting protocols to disease incidence in the same population using an externally validated population-based consortium. Population-based study spanning 1,945,007 person-years. Large tertiary referral center. Adults with sporadic vestibular schwannoma. Disease incidence rates from 2004 to 2016. From 2004 to 2016, the incidence of vestibular schwannoma in the tumor registry was 1.3 per 100,000 person-years whereas the population-based cohort had an incidence of 4.4 per 100,000 person-years. From 2012 to 2016, the incidence in the tumor registry was 1.4 per 100,000 person-years compared with 5.2 in the population-based cohort. Patients within the population-based cohort were significantly more likely to have smaller tumors at diagnosis (78% intracanalicular versus 45%; p = 0.004) and consequently more likely to undergo management consisting of observation with serial imaging as opposed to treatment with either microsurgery or radiosurgery (71% versus 28%; p = 0.001). The reliance on pathology specimens and cancer-related treatment data for the national registration of new cancer and brain tumor diagnoses may introduce selection bias and underreporting of benign brain tumors that frequently involve observation as a primary treatment modality. This selection bias likely accounts for the discrepant incidence rates of vestibular schwannoma reported between the United States and other countries.

National Trends in Surgical Resection of Vestibular Schwannomas.

To characterize the national trend for surgical resection of vestibular schwannoma (VS) and to assess changes in demographics, length of stay (LOS), discharge patterns, and hospital charges. Population-based inpatient registry analysis. National Inpatient Sample and SEER database (Surveillance, Epidemiology, and End Results). Retrospective review of the US National Inpatient Sample and the SEER database from 2001 to 2014 of all patients who underwent resection of VS. A total of 24,380 VS resections were performed. While the annual incidence of VS remained stable at 1.38 per 100,000, surgical volume declined by 36.1%, from 2807 in 2001 to 1795 in 2014 (R2 = 0.58). Total hospital charges more than doubled, from $52,475 in 2001 to $115,164 in 2014 ($4478 per year, R2 = 0.96). While most procedures were performed at large-sized hospitals, this decreased from 89% in 2002 to 75.8% in 2014. Average LOS remained stable at 5.2 days during the study period. The number of discharges to a nursing facility increased from 113 (5.5%) in 2002 to 245 (13.6%) in 2014 (P = .0002). VS resection has evolved in the United States. While the incidence remained stable, surgical volume decreased by 36%, and hospital charges more than doubled. More cases are being performed at smaller hospitals. Although LOS did not vary significantly, there is an increase in nonroutine discharges. These data may guide future research in resource utilization in neurotology.

Rising Incidence of Sporadic Vestibular Schwannoma: True Biological Shift Versus Simply Greater Detection

The incidence of sporadic vestibular schwannoma (VS) has increased significantly over recent decades. The rising incidence of VS has been largely attributed to the increasing use of magnetic resonance imaging (MRI), especially with regard to incidentally diagnosed tumors. However, no study to date has directly investigated this supposed etiology beyond the observation that VS incidence rates have risen in the post-MRI era. Therefore, the primary objective of the current study was to characterize the incidence of head MRIs over the previous two decades in Olmsted County, Minnesota and compare this trend to the incidence of asymptomatic, incidentally diagnosed VS over the same time period. Population-based incidence study. Using the unique resources of the Rochester Epidemiology Project, procedure codes for head MRIs and diagnostic codes for VS among residents of Olmsted County, Minnesota between Jan 1, 1995 and Dec 31, 2016 were retrieved. Incidence rates of head MRI and incidentally diagnosed VS were calculated on a per-year basis. A total of 43,561 head MRIs among 30,002 distinct persons were identified from 1995 to 2016. The incidence of head MRI significantly increased between 1995 and 2003 (p < 0.001), but remained stable between 2004 and 2016 (p = 0.14). Over the same time interval, 25 cases of incidentally diagnosed VS were identified. The incidence of asymptomatic VS increased over time from 0.72 per 100,000 person-years between 1995 and 1999 to 1.29 between 2012 and 2016 (p = 0.058). No plateauing of incidence rates was observed in incidental tumors over the study period. The size of incidentally diagnosed tumors did not change over the study period (p = 0.93), suggesting that the increasing incidence of asymptomatic tumors is not explained by improved diagnostic capability of more recent MRI studies. Despite the plateauing of head MRI incidence rates after 2004, the incidence of asymptotic, incidentally diagnosed VS continued to increase. Our findings suggest that there may be additional contributory etiologies for the rising incidence of VS beyond greater detection alone.

An Update on Epidemiology and Management Trends of Vestibular Schwannomas.

To determine the current epidemiology and management trends for patients with vestibular schwannomas (VS). Retrospective cohort study. The Surveillance, Epidemiology, and End Results (SEER) tumor registry. The SEER database was queried to identify patients diagnosed with VS from 1973 to 2015. Demographics, patient and tumor characteristics, and treatment methods were analyzed. A total of 14,507 patients with VS were identified. The mean age at diagnosis was 55 ± 14.9 years. Age-adjusted incidence from 2006 to 2015 was 1.4 per 100,000 per year and remained relatively stable. Incidence across age varied with sex, as younger women and older men had increased incidences comparatively. A higher percentage of patients underwent surgery alone (43%), followed by observation (32%), radiation alone (23%), and combined radiation and surgery (2%). Age 65 and older was associated with observation (odds ratio [OR] 1.417; p = 0.029) whereas age 20 to 39 and 40 to 49 were associated with surgery (OR 2.013 and 1.935; p < 0.001). Older age was associated with radiation. Larger tumor size was associated with surgery and combined treatment. African American patients and American Indian or Alaskan Native patients were more likely to undergo observation than surgery. The overall incidence of VS is 1.4 per 100,000 per year and has remained relatively stable. There is a trend toward more conservative management with observation, which may be secondary to earlier diagnosis given widespread use of magnetic resonance imaging. Further studies are necessary to investigate differences in disease patterns and disparities in management.

Incidence of Vestibular Schwannoma in Taiwan from 2001 to 2012: A Population-Based National Health Insurance Study.

Vestibular schwannomas, also known as acoustic neuromas, are slow-growing tumors that may lead to asymmetric hearing loss, unilateral tinnitus, and vertigo. Population-based data are lacking regarding the incidence of vestibular schwannoma in Asian populations. The aim of this study was to investigate the incidence of vestibular schwannoma in Taiwan using data from a population-based health claim database. Patients aged 20 years and over with incident cases of vestibular schwannoma between January 1, 2001, and December 31, 2012, were identified from the Longitudinal Health Insurance Database 2000 of the National Health Insurance Research Database (NHIRD), Taiwan, based on the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code 225.1. Only those patients who had received a magnetic resonance imaging scan prior to the diagnosis of vestibular schwannoma were considered as definitive cases. 206 cases of vestibular schwannoma were identified during the interval 2001 to 2012. The overall annual incidence was 2.66 per 100 000 persons (95% confidence interval, 2.32-3.05). The annual incidence rate varied throughout the study period, ranging from 1.74 to 3.72 per 100 000 persons. The highest incidence rate of 4.86 per 100 000 persons was observed in the age group of 60 to 69 years. Based on data from the NHIRD in Taiwan for the years 2001 to 2012, the average annual incidence rate of vestibular schwannoma was found to be 2.66 per 100 000 persons.

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

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.

The diagnostic accuracy of non-imaging screening protocols for vestibular schwannoma in patients with asymmetrical hearing loss and/or unilateral audiovestibular dysfunction: a diagnostic review and meta-analysis.

Currently, all patients presenting with asymmetrical sensorineural hearing loss and/or unilateral audiovestibular dysfunction (i.e. tinnitus, dizziness) undergo MRI, leading to a substantial amount of MRIs with negative findings as the incidence of vestibular schwannoma (VS) in this screening population varies between 1% and 4.7% (i.e. more than 95% of MRIs are negative for VS). The aim was to assess the diagnostic accuracy of different non-imaging screening protocols that can be used prior to MRI to select patients at high risk of VS. Diagnostic review and meta-analysis. We systematically searched MEDLINE, Embase and The Cochrane Library as from inception up to 28 July 2016. We included studies that compared non-imaging screening protocols to MRI as gold reference standard. Methodological quality was assessed by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Data necessary to complete 2 × 2 tables were obtained, and patient, study, screening and imaging characteristics were extracted. We calculated sensitivity and specificity of all tests and obtained pooled estimates using a bivariate random effects model. We analysed 12 studies (4969 patients) of poor to moderate quality according to the quality assessment. Most studies tested diagnostic accuracy of multiple screening protocols. Five pure-tone audiometry (PTA) protocols were studied by multiple authors; pooled estimates for sensitivity ranged from 88% [95% CI: 84-91] to 91% [95% CI: 52-99] and specificity from 31% [95% CI: 10-66] to 58% [95% CI: 49-65]. Due to heterogeneity, we were unable to pool other tests. In five studies testing auditory brainstem response, sensitivity values ranged from 37% [95% CI: 23-52] to 100% [95% CI: 40-100] and specificity from 57% to 96% [95% CI: 87-100]. Two authors studied PTA shape as a screening test. Presenting symptoms, electronystagmography, caloric irrigation and hyperventilation test were assessed by one study each. All reported low diagnostic accuracy. All identified studies had a moderate-to-high risk of bias, and none of the currently available non-imaging screening protocols appear to be accurate in detecting VSs.

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

To identify incidence of vestibular schwannoma (VS) in The Netherlands. Determining incidence of VS poses considerable challenges given the lack of complete epidemiologic data. Retrospective patient review. Tertiary referral center. 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. Magnetic resonance imaging (MRI). Incidence of VS. 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. 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.

Presentation and Clinical Course of Asymptomatic Incidental Vestibular Schwannomas

Objective: Greater access to advanced imaging combined with the high-resolution of modern contrast-enhanced magnetic resonance imaging (MRI) has resulted in a growing number of incidentally diagnosed vestibular schwannomas (VS). Cadaveric studies have demonstrated that the true incidence of VS is much greater than clinically derived estimates suggest. Thus, several patients harbor asymptomatic VS that may never manifest clinically or require treatment during their lifetime. Currently, little data are available regarding the clinical course of incidentally diagnosed VS. Specifically, it is unknown whether these tumors represent a more indolent biological variant. Such information would be beneficial toward patient counseling regarding treatment strategy and surveillance intervals during observation.

The Changing Landscape of Vestibular Schwannoma Management in the United States--A Shift Toward Conservatism.

To characterize the evolving management of vestibular schwannoma (VS) in the United States. Retrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) database. SEER database. All patients with a diagnosis of VS were analyzed. Data were described and compared using trend analyses and univariate and multivariable logistic regression. A total of 8330 patients (average age 54.7 years, 51.9% female) were analyzed. The mean incidence was approximately 1.1 per 100,000 per year and did not vary significantly across time; however, from 2004 to 2011, there was a statistically significant decrease in tumor size category at time of diagnosis (P < .01). Overall, 3982 patients (48%) received primary microsurgery, 1978 (24%) radiation therapy alone, and 2370 (29%) observation. Within the microsurgical cohort, 732 (18%) underwent subtotal resection, and of those, 98 (13.4%) received postoperative radiation therapy. Multivariable regression revealed that surgical treatment was more common in younger patients and larger tumor size categories (P < .05). Management trend analysis revealed that microsurgery was used less frequently over time (P < .0001), observation was used more frequently (P < .0001), and the pattern of radiation therapy remained unchanged. Linear regression was used to create an equation that was applied to predict future management practices. These data predict that by 2026, half of all cases of VS will be managed initially with observation. While the incidence of VS has remained steady, tumor size at time of diagnosis has decreased over time. Within the United States there has been a clear, recent evolution in management toward observation.

Association between vestibular schwannomas and mobile phone use

Vestibular schwannomas (VSs) grow in the region where the energy from mobile phone use is absorbed. We examined the associations of VSs with mobile phone use. This study included 119 patients who had undergone surgical tumor removal. We used two approaches in this investigation. First, a case–control study for the association of mobile phone use and incidence of VSs was conducted. Both cases and controls were investigated with questions based on INTERPHONE guidelines. Amount of mobile phone use according to duration, daily amount, and cumulative hours were compared between two groups. We also conducted a case–case study. The location and volume of the tumors were investigated by MRI. Associations between the estimated amount of mobile phone use and tumor volume and between the laterality of phone use and tumor location were analyzed. In a case–control study, the odds ratio (OR) of tumor incidence according to mobile phone use was 0.956. In the case–case study, tumor volume and estimated cumulative hours showed a strong correlation (r 2 = 0.144, p = 0.002), and regular mobile phone users showed tumors of a markedly larger volume than those of non-regular users (p < 0.001). When the analysis was limited to regular users who had serviceable hearing, laterality showed a strong correlation with tumor side (OR = 4.5). We found that tumors may coincide with the more frequently used ear of mobile phones and tumor volume that showed strong correlation with amount of mobile phone use, thus there is a possibility that mobile phone use may affect tumor growth.Electronic supplementary materialThe online version of this article (doi:10.1007/s13277-013-1081-8) contains supplementary material, which is available to authorized users.