Vestibular schwannomas in the modern era: epidemiology, treatment trends, and disparities in management

Abstract

Object There are a variety of treatment options for the management of vestibular schwannomas (VSs), including microsurgical resection, radiotherapy, and observation. Although the choice of treatment is dependent on various patient factors, physician bias has been shown to significantly affect treatment choice for VS. In this study the authors describe the current epidemiology of VS and treatment trends in the US in the modern era. They also illustrate patient and tumor characteristics and elucidate their effect on tumor management. Methods Patients diagnosed with VS were identified through the Surveillance, Epidemiology, and End Results database, spanning the years 2004–2009. Age-adjusted incidence rates were calculated and adjusted using the 2000 US standard population. The chi-square and Student t-tests were used to evaluate differences between patient and tumor characteristics. Multivariate logistic regression was performed to determine the effects of various patient and tumor characteristics on the choice of tumor treatment. Results A total of 6225 patients with VSs treated between 2004 and 2009 were identified. The overall incidence rate was 1.2 per 100,000 population per year. The median age of patients with VS was 55 years, with the majority of patients being Caucasian (83.16%). Of all patients, 3053 (49.04%) received surgery only, with 1466 (23.55%) receiving radiotherapy alone. Both surgery and radiation were only used in 123 patients (1.98%), with 1504 patients not undergoing any treatment (24.16%). Increasing age correlated with decreased use of surgery (OR 0.95, 95% CI 0.95–0.96; p < 0.0001), whereas increasing tumor size was associated with the increased use of surgery (OR 1.04, 95% CI 1.04–1.05; p < 0.0001). Older age was associated with an increased likelihood of conservative management (OR 1.04, 95% CI 1.04–1.05; p < 0.0001). Racial disparities were also seen, with African American patients being significantly less likely to receive surgical treatment compared with Caucasians (OR 0.50, 95% CI 0.35–0.70; p < 0.0001), despite having larger tumors at diagnosis. Conclusions The incidence of vestibular schwannomas in the US is 1.2 per 100,000 population per year. Although many studies have demonstrated improved outcomes with the use of radiotherapy for small- to medium-sized VSs, surgery is still the most commonly used treatment modality for these tumors. Racial disparities also exist in the treatment of VSs, with African American patients being half as likely to receive surgery and nearly twice as likely to have their VSs managed conservatively despite presenting with larger tumors. Further studies are needed to elucidate the reasons for treatment disparities and investigate the nationwide trend of resection for the treatment of small VSs.

Stereotactic radiosurgery for recurrent vestibular schwannoma after previous resection

“…3,21 The present study extends our patient series and the length of follow-up from our previous report. 20 We analyzed the outcomes of GK SRS for VS patients who had recurrent or residual tumors after 1 or more previous resections.…”

“…The incidence of VS is estimated to be 1 per 100,000 individuals per year, and it accounts for approximately 8% of all intracranial tumors in adults. 3,14 These tumors are typically slow growing (0-3.9 mm per year), but without management, most VS tumors will grow within 3 years. 4,6,14,15,18,20 For many years, microsurgical resection remained the most commonly recommended treatment for patients with newly diagnosed unilateral VS. 3,20 Although surgical outcomes have improved over the last 30 years, resection of VS was frequently associated with impaired facial nerve function and loss of hearing.…”

“…3,14 These tumors are typically slow growing (0-3.9 mm per year), but without management, most VS tumors will grow within 3 years. 4,6,14,15,18,20 For many years, microsurgical resection remained the most commonly recommended treatment for patients with newly diagnosed unilateral VS. 3,20 Although surgical outcomes have improved over the last 30 years, resection of VS was frequently associated with impaired facial nerve function and loss of hearing. 7,13,20,22 The recurrence rate of VS has been shown to be 2.6%-11.0% after gross-total resection, and 20%-50% of VS tumors progress after subtotal resection.…”

Incidence of vestibular schwannomas in the United States

“…Data from studies prior to 2004 likely underestimated the true incidence of vestibular schwannomas since collection of data on non-malignant brain tumors was not mandatory prior to the Benign Brain Tumor Act in 2004. Populationbased studies published after 2004 demonstrate a similar incidence [9,10]. To date, prior studies on the populationbased incidence of vestibular schwannomas in the US collected data from either a single county or national databases covering a maximum of 28 % of the US population [8][9][10].…”

Modern trends in the management of head and neck paragangliomas

“…Watchful waiting and radiotherapy are widely accepted in the management of vestibular schwannomas, a tumor that is usually indolent but, like HNPG, also has an unpredictable growth pattern. Review of different national tumor registry databases revealed that in the United States there has been a significant shift in management of vestibular schwannomas over a decade, with increasing tendency toward observation and radiotherapy, whereas the proportion of operated cases declined to near a half of the total [1][2][3]. Similar studies on the trends of treatment are lacking in HNPG.…”