Phenotypic Expansion of Autosomal Dominant LZTR1-Related Disorders with Special Emphasis on Adult-Onset Features.

Leucine zipper-like transcription regulator 1 (LZTR1) acts as a negative factor that suppresses RAS function and MAPK signaling; mutations in this protein may dysregulate RAS ubiquitination and lead to impaired degradation of RAS superfamily proteins. Germline LZTR1 variants are reported in Noonan syndrome, either autosomal dominant or autosomal recessive, and in susceptibility to schwannomatosis. This article explores the genetic and phenotypic diversity of the autosomal dominant LZTR1-related disorders, compiling a cohort of previously published patients (51 with the Noonan phenotype and 123 with schwannomatosis) and presenting two additional adult-onset cases: a male with schwannomatosis and Parkinson's disease and a female with Noonan syndrome, generalized joint hypermobility, and breast cancer. This review confirms that autosomal dominant LZTR1-related disorders exhibit an extreme phenotypic variability, ranging from relatively mild manifestations to severe and multi-systemic involvement, and offers updated frequences of each clinical feature. The aim is to precisely define the clinical spectrum of LZTR1-related diseases, using also two new emblematic clinical cases. Gaining insight into the mechanisms underneath this variability is crucial to achieve precision diagnostics and the development of therapeutic interventions.

NF2-Related Schwannomatosis (NF2): Molecular Insights and Therapeutic Avenues.

NF2-related schwannomatosis (NF2) is a genetic syndrome characterized by the growth of benign tumors in the nervous system, particularly bilateral vestibular schwannomas, meningiomas, and ependymomas. This review consolidates the current knowledge on NF2 syndrome, emphasizing the molecular pathology associated with the mutations in the gene of the same name, the NF2 gene, and the subsequent dysfunction of its product, the Merlin protein. Merlin, a tumor suppressor, integrates multiple signaling pathways that regulate cell contact, proliferation, and motility, thereby influencing tumor growth. The loss of Merlin disrupts these pathways, leading to tumorigenesis. We discuss the roles of another two proteins potentially associated with NF2 deficiency as well as Merlin: Yes-associated protein 1 (YAP), which may promote tumor growth, and Raf kinase inhibitory protein (RKIP), which appears to suppress tumor development. Additionally, this review discusses the efficacy of various treatments, such as molecular therapies that target specific pathways or inhibit neomorphic protein-protein interaction caused by NF2 deficiency. This overview not only expands on the fundamental understanding of NF2 pathophysiology but also explores the potential of novel therapeutic targets that affect the clinical approach to NF2 syndrome.

[Features of course of pain syndrome in patients with schwannomatosis]. / Osobennosti techeniya bolevogo sindroma u patsientov s shvannomatozami.

OBJECTIVE: To identify the characteristics of pain syndrome in patients with schwannomas depending on genetic predisposition. MATERIAL AND METHODS: The study included 46 patients with peripheral, spinal and intracranial schwannomas, corresponding to the schwannomatosis phenotype according to the 2022 clinical criteria. All patients underwent sequencing of the LZRT1, Nf2 and SMARCB1 and a copy number study in the NF2. RESULTS: The most severe widespread pain was observed in patients with pathogenic LZRT1 variants, while patients with mosaic variants may not even have local tumor-related pain. Patients with SMARCB1variants may have no pain or have localized pain that responds well to surgical treatment. CONCLUSION: Further studies of the molecular features of schwannomatosis and driver mutations in the pathogenesis of pain are necessary to improve the effectiveness of pain therapy in this group of patients. Schwannomatosis is a disease from the group of neurofibromatosis, manifested by the development of multiple schwannomas. Neuropathic pain is one of the main symptoms characteristic of peripheral schwannomas, however, the severity and prevalence of the pain syndrome does not always correlate with the location of the tumors. According to modern concepts, the key factors influencing the characteristics of the pain syndrome are the target gene and the type of pathogenic variant. The most severe widespread pain is observed in patients with pathogenic variants in the LZRT1 gene, while patients with mosaic variants may not even have local pain associated with tumors. Patients with variants in SMARCB1 may have no pain or localized pain that responds well to surgical treatment.

Historical Development of Diagnostic Criteria for NF2-related Schwannomatosis.

NF2-related schwannomatosis (NF2; previously termed neurofibromatosis type 2) is a tumor-prone disorder characterized by development of multiple schwannomas and meningiomas. The diagnostic criteria of NF2 have been regularly revised. Clinical criteria for NF2 were first formulated at the National Institutes of Health Consensus Conference in 1987 and revised in 1990. Revised criteria were also proposed by the Manchester group in 1992 and by the National Neurofibromatosis Foundation (NNFF) in 1997. The 2011 Baser criteria improved the sensitivity of diagnostic criteria, particularly for patients without bilateral vestibular schwannomas. Revisions to the Manchester criteria were published in 2019, with replacement of "glioma" by "ependymoma," removal of "neurofibroma," addition of an age limit of 70 years for development of vestibular schwannomas, and introduction of molecular criteria, which led to the most widely used criteria. In 2022, the criteria were reviewed and updated by the international committee of NF experts. In addition to changes in diagnostic criteria, the committee recommended the use of "schwannomatosis" as an umbrella term for conditions that predispose to schwannomas. Each type of schwannomatosis was classified by the gene containing the disease-causing pathogenic variant. Molecular data from NF2 patients led to further clarification of the diagnostic criteria for NF2 mosaic phenotypes. Given all these changes, the diagnostic criteria of NF2 may be confusing. Herein, to help healthcare professionals who diagnose NF2 conditions in the clinical setting, we review the historical development of diagnostic criteria.

Phase I/II Study of a Vascular Endothelial Growth Factor Receptor Vaccine in Patients With NF2-Related Schwannomatosis.

PURPOSE: The humanized antivascular endothelial growth factor (VEGF) antibody bevacizumab (Bev) is efficacious for the treatment of NF2-related schwannomatosis (NF2), previously known as neurofibromatosis type 2. This study evaluated the safety and efficacy of a VEGF receptor (VEGFR) vaccine containing VEGFR1 and VEGFR2 peptides in patients with NF2 with progressive schwannomas (jRCTs031180184). MATERIALS AND METHODS: VEGFR1 and VEGFR2 peptides were injected subcutaneously into infra-axillary and inguinal regions, once a week for 4 weeks and then once a month for 4 months. The primary end point was safety. Secondary end points included tolerability, hearing response, imaging response, and immunologic response. RESULTS: Sixteen patients with NF2 with progressive schwannomas completed treatment and were assessed. No severe vaccine-related adverse events occurred. Among the 13 patients with assessable hearing, word recognition score improved in five patients at 6 months and two at 12 months. Progression of average hearing level of pure tone was 0.168 dB/mo during the year of treatment period, whereas long-term progression was 0.364 dB/mo. Among all 16 patients, a partial response was observed in more than one schwannoma in four (including one in which Bev had not been effective), minor response in 5, and stable disease in 4. Both VEGFR1-specific and VEGFR2-specific cytotoxic T lymphocytes (CTLs) were induced in 11 patients. Two years after vaccination, a radiologic response was achieved in nine of 20 assessable schwannomas. CONCLUSION: This study demonstrated the safety and preliminary efficacy of VEGFR peptide vaccination in patients with NF2. Memory-induced CTLs after VEGFR vaccination may persistently suppress tumor progression.

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).

The impact of mental health on health-related quality of life in patients with NF2-related Schwannomatosis.

NF2-related schwannomatosis (NF2-SWN) is a rare genetic disorder and is associated with progressive morbidities. This study aimed to investigate the relationship between NF2-SWN disease severity, health-related Quality of Life (QoL), and mental health aspects of patients. Standardised questionnaires assessing mental health problems (symptoms of depression, anxiety, and somatic burden), psychological factors (resilience, loneliness, and personality functioning), and health-related QoL were administered to 97 patients with NF2-SWN. The results of these questionnaires were compared with physician-rated disease severity. Questionnaires were completed by 77 patients. Physician-rated disease severity scores were available for 55 patients. NF2-SWN patients showed a high prevalence of clinically relevant symptoms of depression (30%), anxiety (16%), and somatic burden (32%). Almost all variables showed moderate to high correlations with NF2-SWN-related QoL. NF2-SWN-related QoL was associated with physician-reported disease severity (r = 0.614). In the stepwise hierarchical linear regression analysis, a significant model with four predictors (disease severity type, depression symptoms, personality functioning, and gender) explained 64% of the variance in NF2-SWN-related QoL. Our results showed a strong association between NF2-SWN-related QoL and depression symptoms. Moreover, personality functioning is an important influencing factor, representing a modifiable construct that can be targeted by prevention programs or psychotherapy.

Auditory brainstem implants for hearing rehabilitation in NF2-schwannomatosis: A systematic review and single-arm meta-analysis.

BACKGROUND: NF2-schwannomatosis (NF2) is an autosomal dominant disorder prone to hearing loss. Auditory brainstem implants (ABIs) offer a promising solution for hearing rehabilitation in NF2. OBJECTIVE: To synthesize existing literature on ABI implantation in NF2, focusing on audiological outcomes and ABI-related complications. METHODS: The systematic review followed PRISMA guidelines and was registered in the PROSPERO database (CRD42022362155). Relevant studies were identified by searching PubMed, EMBASE, CENTRAL, CMB, and CNKI from inception to August 2023. Data on environmental sound discrimination, open-set discrimination, closed-set discrimination, and ABI-related complications were extracted and subjected to meta-analysis. Publication bias was evaluated using funnel plots and Egger's test. RESULTS: Thirty-three studies were included. The pooled estimate was 58% (95% CI 49-66%) for environmental sound discrimination and 55% (95% CI 40-69%) for closed-set discrimination. Regarding open-set discrimination, the pooled estimates were 30% (95% CI 19-42%) for sound only, 46% (95% CI 37-54%) for lip-reading only, and 63% (95% CI 55-70%) for sound plus lip-reading. The pooled occurrence of ABI-related complications was 33% (95% CI 15-52%). CONCLUSION: This meta-analysis underscores the effectiveness and safety of ABIs in NF2, providing valuable insights for evidence-based decision-making and hearing rehabilitation strategies.

An unusual finding of an anaplastic meningioma in NF2-related schwannomatosis.

NF2-related schwannomatosis (NF2) is a rare autosomal-dominant genetic disorder characterized by bilateral vestibular schwannomas and multiple meningiomas. This case report presents the extremely rare occurrence of an anaplastic meningioma in a 12-year-old male with previously undiagnosed NF2. The patient presented with a history of abdominal pain and episodic emesis, gait unsteadiness, right upper and lower extremity weakness, and facial weakness. He had sensorineural hearing loss and wore bilateral hearing aids. MR imaging revealed a sizable left frontoparietal, dural-based meningioma with heterogeneous enhancement with mass effect on the brain and midline shift. Multiple additional CNS lesions were noted including a homogenous lesion at the level of T5 indicative of compression of the spinal cord. The patient underwent a frontotemporoparietal craniotomy for the removal of his large dural-based meningioma, utilizing neuronavigation and transdural ultrasonography for precise en bloc resection of the mass. Histopathology revealed an anaplastic meningioma, WHO grade 3, characterized by brisk mitotic activity, small-cell changes, high Ki-67 proliferation rate, and significant loss of P16. We report an anaplastic meningioma associated with an underlying diagnosis of NF2 for which we describe clinical and histopathological features.

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.

Four distinct ipsilateral vestibular schwannomas: A case of mosaic NF2-related schwannomatosis.

OBJECTIVES: Distinguishing between sporadic and germline/mosaic NF2-related schwannomatosis is important to ensure that patients have appropriate long-term care. With this report, we describe a unique case of a patient with 4 ipsilateral schwannomas and identify a combination of sequencing modalities that can accurately diagnose mosaic NF2-related schwannomatosis. METHODS: We present a 32-year-old woman with a familial history of vestibular schwannoma in her father and right-sided schwannomas involving the apical and basal turns of cochlea, lateral semicircular canal, and internal auditory canal (IAC). Genetic analysis of blood and frozen tissue from 2 tumors (intralabyrinthine and IAC tumors) was performed using next-generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), and optical genome mapping (OGM). RESULTS: Germline testing for NF2, LZTR1, and SMARCB1 was negative. Tumor genetic testing revealed a shared NF2 pathogenic variant between the 2 tumors ("first hit") but distinct "second hit" NF2 variants, including mosaic loss of chromosome 22 in the IAC tumor seen only with OGM, consistent with mosaic NF2-related schwannomatosis. CONCLUSIONS: Multimodality sequencing, including NGS, MLPA, and OGM, was required to ensure appropriate diagnosis of mosaic NF2-related schwannomatosis in this patient. A similar approach can be used for other patients with multiple ipsilateral tumors and suspected tumor predisposition.

Simultaneous inhibition of PI3K and PAK in preclinical models of neurofibromatosis type 2-related schwannomatosis.

Neurofibromatosis Type 2 (NF2)-related schwannomatosis is a genetic disorder that causes development of multiple types of nervous system tumors. The primary and diagnostic tumor type is bilateral vestibular schwannoma. There is no cure or drug therapy for NF2. Recommended treatments include surgical resection and radiation, both of which can leave patients with severe neurological deficits or increase the risk of future malignant tumors. Results of our previous pilot high-throughput drug screen identified phosphoinositide 3-kinase (PI3K) inhibitors as strong candidates based on loss of viability of mouse merlin-deficient Schwann cells (MD-SCs). Here we used novel human schwannoma model cells to conduct combination drug screens. We identified a class I PI3K inhibitor, pictilisib and p21 activated kinase (PAK) inhibitor, PF-3758309 as the top combination due to high synergy in cell viability assays. Both single and combination therapies significantly reduced growth of mouse MD-SCs in an orthotopic allograft mouse model. The inhibitor combination promoted cell cycle arrest and apoptosis in mouse merlin-deficient Schwann (MD-SCs) cells and cell cycle arrest in human MD-SCs. This study identifies the PI3K and PAK pathways as potential targets for combination drug treatment of NF2-related schwannomatosis.

Concurrent spinal meningioma and giant invasive schwannoma without neurofibromatosis in children: A case report and literature review.

BACKGROUND: Spinal meningiomas coexisting with schwannomas in patients without neurofibromatosis are extremely rare lesions. There were only 15 cases reported to date, which were concurrent intradural tumors of different pathological types. CASE PRESENTATION: Herein, we present a rare case of a 15-year-old child with concurrent spinal dorsal meningioma and ventral giant invasive schwannoma at C7-T3 and T10-S5 spinal levels. Preoperative magnetic resonance imaging and computed tomography indicated the schwannoma across the thoracic and lumbosacral transitional vertebra, with extensive bony erosion of the sacrum. The results of surgical resection were mostly satisfactory. CONCLUSIONS: The present case is the youngest patient diagnosed with concurrent intradural tumors at different spinal levels. The pathogenetic mechanism remains unclear. The clinical presentations are always atypical. Surgical resection of the tumors is the first choice. We use the non-fusion surgery to preserve the function of the lumbar spine.

Patient-reported measures of tinnitus for individuals with neurofibromatosis type 2-related schwannomatosis: Recommendations for clinical trials.

BACKGROUND: Neurofibromatosis type 2-related schwannomatosis is a genetic disease characterized by the development of bilateral vestibular schwannomas, ependymomas, meningiomas, and cataracts. Mild to profound hearing loss and tinnitus are common symptoms reported by individuals with neurofibromatosis type 2. While tinnitus is known to have a significant and negative impact on the quality of life of individuals from the general population, the impact on individuals with neurofibromatosis type 2 is unknown. Consensus regarding the selection of suitable patient-reported outcome measures for assessment could advance further research into tinnitus in neurofibromatosis type 2 patients. The purpose of this work is to achieve a consensus recommendation by the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration for patient-reported outcome measures used to evaluate quality of life in the domain of tinnitus for neurofibromatosis type 2 clinical trials. METHODS: The Response Evaluation in Neurofibromatosis and Schwannomatosis Patient-Reported Outcomes Communication Subgroup systematically evaluated patient-reported outcome measures of quality of life in the domain of tinnitus for individuals with neurofibromatosis type 2 using previously published Response Evaluation in Neurofibromatosis and Schwannomatosis rating procedures. Of the 19 identified patient-reported outcome measures, 3 measures were excluded because they were not validated as an outcome measure or could not have been used as a single outcome measure for a clinical trial. Sixteen published patient-reported outcome measures for the domain of tinnitus were scored and compared on their participant characteristics, item content, psychometric properties, and feasibility for use in clinical trials. RESULTS: The Tinnitus Functional Index was identified as the most highly rated measure for the assessment of tinnitus in populations with neurofibromatosis type 2, due to strengths in the areas of item content, psychometric properties, feasibility, and available scores. DISCUSSION: Response Evaluation in Neurofibromatosis and Schwannomatosis currently recommends the Tinnitus Functional Index for the assessment of tinnitus in neurofibromatosis type 2 clinical trials.

Transmaxillary approach for resection of maxillary division trigeminal schwannoma at foramen rotundum.

BACKGROUND: The foramen rotundum and anterior cavernous sinus have traditionally been accessed by transcranial approaches that are limited by the high density of critical neurovascular structures. The transmaxillary approach provides an entirely extradural route to the foramen rotundum and anterior cavernous sinus. METHOD: This patient with neurofibromatosis and facial pain with trigeminal schwannoma at the foramen rotundum was successfully treated by transmaxillary resection of the tumor. This approach allowed for a direct extradural access to the pathology, with bony decompression and tumor resection, avoiding transcranial routes. CONCLUSION: The transmaxillary approach provides a safe and entirely extradural corridor to access smaller localized skull base lesions at and surrounding the cavernous sinus.

Improved sensitivity for detection of pathogenic variants in familial NF2-related schwannomatosis.

PURPOSE: To determine the impact of additional genetic screening techniques on the rate of detection of pathogenic variants leading to familial NF2-related schwannomatosis. METHODS: We conducted genetic screening of a cohort of 168 second-generation individuals meeting the clinical criteria for NF2-related schwannomatosis. In addition to the current clinical screening techniques, targeted next-generation sequencing (NGS) and multiplex ligation-dependent probe amplification analysis, we applied additional genetic screening techniques, including karyotype and RNA analysis. For characterisation of a complex structural variant, we also performed long-read sequencing analysis. RESULTS: Additional genetic analysis resulted in increased sensitivity of detection of pathogenic variants from 87% to 95% in our second-generation NF2-related schwannomatosis cohort. A number of pathogenic variants identified through extended analysis had been previously observed after NGS analysis but had been overlooked or classified as variants of uncertain significance. CONCLUSION: Our study indicates there is added value in performing additional genetic analysis for detection of pathogenic variants that are difficult to identify with current clinical genetic screening methods. In particular, RNA analysis is valuable for accurate classification of non-canonical splicing variants. Karyotype analysis and whole genome sequencing analysis are of particular value for identification of large and/or complex structural variants, with additional advantages in the use of long-read sequencing techniques.

Diverse learners: learning disabilities and quality of life following mind-body and health education interventions for adults with neurofibromatosis.

PURPOSE: Neurofibromatosis (NF) is associated with low quality-of-life (QoL). Learning disabilities are prevalent among those with NF, further worsening QoL and potentially impacting benefits from mind-body and educational interventions, yet research on this population is scarce. Here, we address this gap by comparing NF patients with and without learning disabilities on QoL at baseline and QoL-related gains following two interventions. METHODS: Secondary analysis of a fully-powered RCT of a mind-body program (Relaxation Response Resiliency Program for NF; 3RP-NF) versus an educational program (Health Enhancement Program for NF; HEP-NF) among 228 adults with NF. Participants reported QoL in four domains (Physical Health, Psychological, Social Relationships, and Environmental). We compare data at baseline, post-treatment, and 12-month follow-up, controlling for intervention type. RESULTS: At baseline, individuals with NF and learning disabilities had lower Psychological (T = -3.0, p = .001) and Environmental (T = -3.8, p < .001) QoL compared to those without learning disabilities. Both programs significantly improved all QoL domains (ps < .0001-0.002) from baseline to post-treatment, regardless of learning disability status. However, those with learning disabilities exceeded the minimal clinically important difference in only one domain (Psychological QoL) compared to three domains in individuals without learning disabilities. Moreover, those with learning disabilities failed to sustain statistically significant gains in Psychological QoL at 12-months, while those without learning disabilities sustained all gains. CONCLUSION: Adults with NF and learning disabilities have lower Psychological and Environmental QoL. While interventions show promise in improving QoL regardless of learning disabilities, additional measures may bolster clinical benefit and sustainability among those with learning disabilities.

The impact of a virtual mind-body program on symptoms of depression and anxiety among international English-speaking adults with neurofibromatosis.

The neurofibromatoses (NFs) are a set of incurable genetic disorders that predispose individuals to nervous system tumors. Although many patients experience anxiety and depression, there is little research on psychosocial interventions in this population. The present study examined the effects of a mind-body intervention on depression and anxiety in adults with NF. This is a secondary analysis of the Relaxation Response Resiliency Program for NF (3RP-NF), an 8-week virtual group intervention that teaches mind-body skills (e.g., relaxation, mindfulness) to improve quality of life. Participants were randomized to 3RP-NF or the Health Enhancement Program for NF (HEP-NF) consisting of health informational sessions and discussion. We evaluated depression (PHQ-9) and anxiety (GAD-7) at posttreatment, 6 months, and 12 months. Both groups improved in depression and anxiety between baseline and posttest, 6 months, and 12 months. The 3RP-NF group showed greater improvements in depression scores from baseline to 6 months compared with HEP-NF and with lower rates of clinically significant depressive symptoms. There were no between-group differences for anxiety. Both interventions reduced distress and anxiety symptoms for individuals with NF. The 3RP-NF group may be better at sustaining these improvements. Given the rare nature of NF, group connection may facilitate reduced distress.

Minimal clinically important difference in the World Health Organization Quality of Life Brief (WHOQOL-BREF) for adults with neurofibromatosis.

PURPOSE: This study aimed to estimate minimal clinically important difference (MCID) values for the World Health Organization Quality of Life Brief version (WHOQOL-BREF) among adults with neurofibromatosis (NF). An MCID is needed to demonstrate clinical meaningfulness of interventions for NF. METHODS: We estimated MCID for the WHOQOL-BREF: the quality of life (QoL) measure recommended by the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration. We used data from 228 clinical trial participants with NF type 1, NF type 2-related schwannomatosis, or schwannomatosis (SCHWN) who completed 10 weeks of a virtual group mind-body program targeting resiliency or a time- and attention-matched control. Following established guidelines, we estimated MCIDs using both anchor-based and distribution-based methods for physical, psychological, social relationships, and environmental domains of the WHOQOL-BREF. RESULTS: MCID results varied across method and QoL domain. Three anchor-based methods, average change (AC), change difference (CD), and regression (REG), yielded the most consistent and comparable MCID across QoL domains. Based on these methods, we recommend ranges for each QoL domain: Physical QoL (3.9-7.3), Psychological QoL (4.7-8.1), Social QoL (2.6-5.9), and Environmental QoL (4.1-6.6). CONCLUSION: Establishing a rigorous MCID for QoL in NF is a critical step toward evaluating meaningful change in response to psychosocial interventions.

Functional interactions between neurofibromatosis tumor suppressors underlie Schwann cell tumor de-differentiation and treatment resistance.

Schwann cell tumors are the most common cancers of the peripheral nervous system and can arise in patients with neurofibromatosis type-1 (NF-1) or neurofibromatosis type-2 (NF-2). Functional interactions between NF1 and NF2 and broader mechanisms underlying malignant transformation of the Schwann lineage are unclear. Here we integrate bulk and single-cell genomics, biochemistry, and pharmacology across human samples, cell lines, and mouse allografts to identify cellular de-differentiation mechanisms driving malignant transformation and treatment resistance. We find DNA methylation groups of Schwann cell tumors can be distinguished by differentiation programs that correlate with response to the MEK inhibitor selumetinib. Functional genomic screening in NF1-mutant tumor cells reveals NF2 loss and PAK activation underlie selumetinib resistance, and we find that concurrent MEK and PAK inhibition is effective in vivo. These data support a de-differentiation paradigm underlying malignant transformation and treatment resistance of Schwann cell tumors and elucidate a functional link between NF1 and NF2.