Natural history of vestibular schwannomas and hearing loss in NF2 patients

Long-term analysis of ABI auditory performance in patients with neurofibromatosis type 2-related schwannomatosis

PURPOSE

This retrospective monocentric study aimed to evaluate long-term auditory brainstem implant (ABI) function in patients with neurofibromatosis type 2, and to investigate the prognostic factors for ABI use.

METHODS

Between 1997 and 2022, 27 patients with at least five years of follow-up underwent implantation with 32 ABIs. At 1- and 5-years post-implantation and at last follow-up, ABIs were classified as used or non-used and the size of the ipsilateral tumor was recorded. For patients who used their ABIs, we assessed speech perception (disyllabic words, MBAA sentences) in quiet conditions with the ABI only, by lip-reading (LR), and with a combination of the two (ABI + LR). Hearing improvement was calculated as Δ ABI = (ABI + LR)-LR scores. Predictive factors for ABI use were analyzed.

RESULTS

One year post-implantation, 74% patients were ABI-users and 66% of the ABIs were used. Two of these patients were non-users at five years, and another two at last follow-up (14 ± 5.2 years); 54% of the patients were ABI-users at last follow-up. Δ ABI revealed a hearing improvement of 32-41% (disyllabic words) and 28-37% (MBAA sentences). Among 16 ABIs with at least LR improvement at 1-year post-implantation, 4 decreased their performance, coinciding with a large growing ipsilateral tumor in 3/4 ABIs. We identified no significant prognostic factors for ABI use.

CONCLUSIONS

ABIs are indicated in case of bilateral deafness with a non-functional cochlear nerve. Half the patients with ABIs used their implants and auditory performance remained stable over time, except in cases of ipsilateral tumor growth.

Natural history of hearing and tumor growth in vestibular schwannoma in neurofibromatosis type 2-related schwannomatosis

OBJECTIVES

To determine the natural history of hearing loss and tumor volume in patients with untreated neurofibromatosis type 2 (NF2)-related schwannomatosis. Moreover, we statistically examined the factors affecting hearing prognosis.

METHODS

This retrospective cohort study was conducted on 37 ears of 24 patients with NF2-related vestibular schwannomatosis followed up without treatment for more than 1 year. We obtained detailed chronological changes in the PTA and tumor volume in each case over time, and the rate of change per year was obtained. Multivariate analysis was also conducted to investigate factors associated with changes in hearing.

RESULTS

The average follow-up period was approximately 9 years, and hearing deteriorated at an average rate of approximately 4 dB/year. The rate of maintaining effective hearing decreased from 30 ears (81%) at the first visit to 19 ears (51%) at the final follow-up. The average rate of change in tumor growth for volume was approximately 686.0 mm3/year. This study revealed that most patients with NF2 experienced deterioration in hearing acuity and tumor growth during the natural course. A correlation was observed between an increase in tumor volume and hearing loss (r = 0.686; p < 0.001).

CONCLUSIONS

Although the hearing preservation rate in NF2 cases is poor with the current treatment methods, many cases exist in which hearing acuity deteriorates, even during the natural course. Patients with an increased tumor volume during the follow-up period were more likely to experience hearing deterioration. Trial registration number 20140242 (date of registration: 27 October 2014).

Cochlear Implantation in Neurofibromatosis Type 2-Related Schwannomatosis: Long-Term Hearing Outcomes

OBJECTIVE

To evaluate long-term hearing outcomes following cochlear implantation in patients with neurofibromatosis type 2 and ipsilateral vestibular schwannoma.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary general hospital.

METHODS

Twenty-two patients undergoing cochlear implantation between 2004 and 2018 with at least 1 year of follow-up were included. Patients were categorized as "users" or "nonusers" of their cochlear implant (CI). For users, speech perception (disyllabic words) without lip-reading was assessed in quiet conditions 1-year postimplantation, and annually thereafter. CI users were classified into 2 groups on the basis of speech intelligibility (≥40% or <40%). Demographic data, treatment options, and tumor size were also recorded.

RESULTS

One year after implantation, 16 (73%) patients used their CI daily. Twelve of these patients had a speech intelligibility ≥40% (mean: 74 ± 21.9%). Three had a Koos stage IV tumor. At the last visit (mean duration of follow-up: 6 ± 5 years), 12 of these 16 patients were still using their implant daily, and 6 had a speech intelligibility ≥40%. No predictive factors for good performance at 1 year or performance stability were identified.

CONCLUSION

Neurofibromatosis type 2 is a complex disease profoundly affecting patient quality of life, and cochlear implantation should always be considered on a case-by-case basis. In some individuals, cochlear implantation can provide good speech intelligibility for extended periods, even posttreatment or in cases of large tumors.

Imaging as an early biomarker to predict sensitivity to everolimus for progressive NF2-related vestibular schwannoma

PURPOSE

NF2-related schwannomatosis (NF2) is characterized by bilateral vestibular schwannomas (VS) often causing hearing and neurologic deficits, with currently no FDA-approved drug treatment. Pre-clinical studies highlighted the potential of mTORC1 inhibition in delaying schwannoma progression. We conducted a prospective open-label, phase II study of everolimus for progressive VS in NF2 patients and investigated imaging as a potential biomarker predicting effects on growth trajectory.

METHODS

The trial enrolled 12 NF2 patients with progressive VS. Participants received oral everolimus daily for 52 weeks. Brain imaging was obtained quarterly. As primary endpoint, radiographic response (RR) was defined as ≥ 20% decrease in target VS volume. Secondary endpoints included other tumors RR, hearing outcomes, drug safety and quality of life (QOL).

RESULTS

Eight participants completed the trial and four discontinued the drug early due to significant volumetric VS progression. After 52 weeks of treatment, the median annual VS growth rate decreased from 77.2% at baseline to 29.4%. There was no VS RR and 3 of 8 (37.5%) participants had stable disease. Decreased or unchanged VS volume after 3 months of treatment was predictive of stabilization at 12 months. Seven of eight participants had stable hearing during treatment except one with a decline in word recognition score. Ten of twelve participants reported only minimal changes to their QOL scores.

CONCLUSIONS

Volumetric imaging at 3 months can serve as an early biomarker to predict long-term sensitivity to everolimus treatment. Everolimus may represent a safe treatment option to decrease the growth of NF2-related VS in patients who have stable hearing and neurological condition. TRN: NCT01345136 (April 29, 2011).

Stereotactic Radiosurgery for Vestibular Schwannoma in Neurofibromatosis Type 2: An International Multicenter Case Series of Response and Malignant Transformation Risk

BACKGROUND

Vestibular schwannomas (VSs) related to neurofibromatosis type 2 (NF2) are challenging tumors. The increasing use of stereotactic radiosurgery (SRS) necessitates further investigations of its role and safety.

OBJECTIVE

To evaluate tumor control, freedom from additional treatment (FFAT), serviceable hearing preservation, and radiation-related risks of patients with NF2 after SRS for VS.

METHODS

We performed a retrospective study of 267 patients with NF2 (328 VSs) who underwent single-session SRS at 12 centers participating in the International Radiosurgery Research Foundation. The median patient age was 31 years (IQR, 21-45 years), and 52% were male.

RESULTS

A total of 328 tumors underwent SRS during a median follow-up time of 59 months (IQR, 23-112 months). At 10 and 15 years, the tumor control rates were 77% (95% CI: 69%-84%) and 52% (95% CI: 40%-64%), respectively, and the FFAT rate were 85% (95% CI: 79%-90%) and 75% (95% CI: 65%-86%), respectively. At 5 and 10 years, the serviceable hearing preservation rates were 64% (95% CI: 55%-75%) and 35% (95% CI: 25%-54%), respectively. In the multivariate analysis, age (hazards ratio: 1.03 [95% CI: 1.01-1.05]; P = .02) and bilateral VSs (hazards ratio: 4.56 [95% CI: 1.05-19.78]; P = .04) were predictors for serviceable hearing loss. Neither radiation-induced tumors nor malignant transformation were encountered in this cohort.

CONCLUSION

Although the absolute volumetric tumor progression rate was 48% at 15 years, the rate of FFAT related to VS was 75% at 15 years after SRS. None of the patients with NF2-related VS developed a new radiation-related neoplasm or malignant transformation after SRS.

Multiple Meningiomas as a Criterion for the Diagnosis of Neurofibromatosis Type 2 and Other Tumor Predisposition Syndromes

BACKGROUND

Bilateral vestibular schwannomas (VS) are pathognomonic of neurofibromatosis type 2 (NF2), but the diagnostic criteria also include unilateral VS (UVS) in combination with multiple meningiomas (MM) and other schwannomas, as well as MM without VS.

OBJECTIVE

To investigate the diagnostic value of these criteria and establish the presence of other genetic conditions in patients presenting in this manner.

METHODS

The Manchester International NF2 database was accessed to obtain information on patients presenting with a UVS and MM or ≥2 nonintradermal schwannomas (NIDS). We gathered data on patients diagnosed with NF2 due to MM without VS and on patients presenting with MM without meeting NF2 criteria. Analysis was performed for pathogenic variants (PVs) in NF2, SMARCE1, SMARCB1, and LZTR1.

RESULTS

A total of 31 of 131 patients presenting with a UVS and MM had a nonrefuted diagnosis of NF2 after molecular studies, in comparison with 85 of 96 patients presenting with UVS and ≥2 NIDS (P ≤ .00001). Fifty percent of patients presenting with a UVS and ≥2 NIDS with NF2 developed bilateral VS, compared with only 26% of those who presented with a UVS and MM (P = .0046). In total, 11 of 152 patients presenting with MM without fulfilling NF2 criteria were found to have a PV in SMARCE1, and 7 of 152 were confirmed to have mosaic NF2.

CONCLUSION

Patients presenting with UVS and MM are significantly more likely to have a nonrefuted diagnosis of NF2 than patients presenting with UVS and ≥2 NIDS, but significantly less likely to develop bilateral VS. Seven percent of those presenting with MM without meeting NF2 criteria had PV in SMARCE1, and 5% had mosaic NF2.

Stereotactic radiosurgery for vestibular schwannomas in neurofibromatosis type 2 patients: a systematic review and meta-analysis

INTRODUCTION

Neurofibromatosis type 2 (NF2) is characterized by often bilateral vestibular schwannomas (VS) that result in progressive hearing loss and compression of nearby brainstem structures causing cranial nerve palsies. Treatment of these tumors remains challenging, as both surgical removal and expectant management can result in symptom progression. Stereotactic radiosurgery (SRS) has been investigated for the management of NF2-associated VS; however, the role, promises, and pitfalls of this treatment modality remain unclear.

METHODS

Ovid MEDLINE, EMBASE, Web of Science, and Cochrane Reviews were searched for studies assessing SRS outcome in NF2-associated VS only. Primary endpoints included tumor control, serviceable hearing, presence of tinnitus, and cranial nerve V and VII symptoms.

RESULTS

A total of 16 studies (589 patients harboring 750 tumors) were analyzed. Clinical tumor control was achieved in 88% of cases (95% CI 80-95%); salvage surgery was needed in 8% (95% CI 4-13%) of cases. Treatment resulted in a worsening of pre-treatment serviceable hearing (OR = 0.26, p < 0.01), increased facial nerve (OR = 1.62, p < 0.01) and trigeminal nerve (OR = 1.42, p = 0.07) impairment. The incidence of vestibular symptoms and hydrocephalus were not consistently reported and thus could not be assessed.

CONCLUSIONS

The treatment of NF2-associated VS continues to pose a challenge, as current SRS regimens result in impaired hearing and worse cranial nerve comorbidities, despite achieving high tumor control. It remains unclear if these findings have to be regarded as treatment complications or, rather, continued disease progression.

Disease course of neurofibromatosis type 2: a 30-year follow-up study of 353 patients seen at a single institution

BACKGROUND

Limited data exist on the disease course of neurofibromatosis type 2 (NF2) to guide clinical trial design.

METHODS

A prospective database of patients meeting NF2 diagnostic criteria, reviewed between 1990 and 2020, was evaluated. Follow-up to first vestibular schwannoma (VS) intervention and death was assessed by univariate analysis and stratified by age at onset, era referred, and inheritance type. Interventions for NF2-related tumors were assessed. Cox regression was performed to determine the relationship between individual factors from time of diagnosis to NF2-related death.

RESULTS

Three hundred and fifty-three patients were evaluated. During 4643.1 follow-up years from diagnosis to censoring, 60 patients (17.0%) died. The annual mean number of patients undergoing VS surgery or radiotherapy declined, from 4.66 and 1.65, respectively, per 100 NF2 patients in 1990-1999 to 2.11 and 1.01 in 2010-2020, as the number receiving bevacizumab increased (2.51 per 100 NF2 patients in 2010-2020). Five patients stopped bevacizumab to remove growing meningioma or spinal schwannoma. 153/353 (43.3%) had at least one neurosurgical intervention/radiation treatment within 5 years of diagnosis. Patients asymptomatic at diagnosis had longer time to intervention and better survival compared to those presenting with symptoms. Those symptomatically presenting <16 and >40 years had poorer overall survival than those presenting at 26-39 years (P = .03 and P = .02, respectively) but those presenting between 16 and 39 had shorter time to VS intervention. Individuals with de novo constitutional variants had worse survival than those with de novo mosaic or inherited disease (P = .004).

CONCLUSION

Understanding disease course improves prognostication, allowing for better-informed decisions about care.

Differential Impact of Advanced Age on Clinical Outcomes After Vestibular Schwannoma Resection in the Very Elderly: Cohort Study

BACKGROUND

Vestibular schwannomas (VS) have a peak incidence in the sixth and seventh decades of life. Stereotactic radiosurgery is often the preferred treatment for VS among patients of advanced age. The fraction of elderly patients potentially requiring consideration for surgical treatment is anticipated to expand, mandating an update to management paradigms in this population.

OBJECTIVE

To describe our experience with surgical management of VS in patients aged 75 yr and older.

METHODS

Cohort study of all patients aged ≥75 yr with sporadic VS requiring surgical treatment at our institution between 1999 and 2020. Data included preoperative baseline characteristics and outcome data including extent of resection, facial nerve and hearing status, functional outcome, length of stay, and complications.

RESULTS

A total of 24 patients were included, spanning an age range of 75 to 90 yr. Average tumor size was 2.76 ± 1.04 cm, and average baseline Modified 5-item Frailty Index (mFI-5) score was 1.08 ± 0.93. Extent of resection was gross total in 5 (20.8%), near total in 3 (12.5%), and sub-total resection in the remaining 16 (66.7%). One patient died in the postoperative period because of an acute sub-dural hematoma. Favorable facial nerve function (HB1-2) was preserved in 12 patients (75%) between 75 and 79 yr and 2 patients (28.6%) aged ≥ 80 yr. No cerebrospinal fluid leak or surgical site infection was observed; 3 patients developed hydrocephalus requiring ventriculo-peritoneal shunt placement. Nine patients required out-of-home disposition; all patients eventually returned to independent living.

CONCLUSION

Microsurgical resection of VS can be safely undertaken in patients greater than 75 y/o but may carry an increased risk of poor facial function.

Current Management of Large Vestibular Schwannomas for NF2 Patients in a National Reference Center

OBJECTIVE

Recently, treatment decision making for large vestibular schwannomas (VS) in patients with neurofibromatosis type 2 (NF2) has become increasingly challenging due to the availability of multiple therapeutic options including surgery, bevacizumab (an anti-VEGF), radiosurgery, and observation; and it often remains an arbitrary decision based on local practices without firm recommendations. Our objective is to discuss the multimodal treatment options for Koos IV VS in a national reference center for NF2.

STUDY DESIGN

Single-institution retrospective cohort study.

METHODS

All NF2 patients with Koos IV VS who visited our center, the National Reference Center for NF2 Rare Disease in Pitié-Salpétrière Hospital of Paris, between January 2016 and December 2018 were included. Clinical charts, radiology, operative reports, and audiograms were reviewed.

RESULTS

Among 54 NF2 patients with Koos IV VS (mean maximum extrameatal diameter: 34 mm; range:17-62 mm), 27 were operated on for 28 VS; 21 were treated with bevacizumab; and six were observed. In the surgical group, VS resections were gross total, near-total, subtotal, or partial in 32%, 25%, 32%, and 11%, respectively; and a good (House-Brackmann grades I-II) facial nerve function was achieved in 81.5% at 1 year. Hearing was preserved in 14%, 78%, and 66% of the surgical (n = 7), bevacizumab (n = 9), and observation (n = 3) patients, respectively.

CONCLUSION

All therapeutic options, including surgery and/or bevacizumab and occasionally observation, should be proposed to NF2 patients with large VS in the setting of dedicated centers. A decision-making tree is proposed for Koos IV VS management based on tumor evolution, hearing and clinical status of the patient, and contralateral VS size.

LEVEL OF EVIDENCE

4, case series study, historically controlled study Laryngoscope, 131:E98-E107, 2021.

Clinical and economic burden of neurofibromatosis type 2 in the United States

OBJECTIVES

We aimed to investigate the prevalence and cost-associated risk factors for hospital stays for Neurofibromatosis Type 2 (NF2) patients in the past decade.

PATIENTS AND METHODS

A multi-year cross-sectional study was performed using the National Inpatient Sample. Patients with a diagnosis code of NF2 according to the International Classification of Diseases, 9th Revision, Clinical Modification coding system were queried from 2006-2014. Sampling discharge weights were used to calculate trend estimates for national demographics, hospital characteristics, comorbidities, and surgical interventions. Regression analysis was performed to determine significant independent associations between comorbidities and admission cost.

RESULTS

From 2006-2014, there were 5,078 discharges for patients diagnosed with NF2. Patient demographics, comorbidities, and procedures performed were overall consistent over time. The most common admission diagnoses were hearing loss (28.2 %), acoustic schwannoma (14.3 %), cranial meningioma (11.8 %) and epilepsy (10.8 %). The most common procedures performed were craniotomy and meningioma resection (10.2 %) and acoustic neuroma open resection (7.9 %). The median inflation-adjusted cost of admission did not change over time, with an admission cost value of $12,387 [6,042 - 26,051]. On regression analysis, obstructive hydrocephalus, craniotomy and meningioma resection, acoustic neuroma open resection, and spine tumor resection were all independent predictors of increased cost.

CONCLUSION

The care for NF2 patients continues to evolve over time. We report the prevalence of patient demographics, comorbidities, and treatments in the NF2 inpatient population. Further studies are warranted to better understand the risk factors for higher costs, so that patients with NF2 may continue to receive life-long quality care in a cost-effective manner.