Prevalence of plexiform neurofibroma in children and adolescents with type I neurofibromatosis

Written language achievement in children and adolescents with neurofibromatosis type 1 and Plexiform Neurofibromas

Neurofibromatosis type 1 (NF1) is associated with below average writing achievement. However, little is known about specific aspects of written language impacted by NF1, changes in writing over time, and associations between cognitive aspects of the NF1 phenotype and writing. At three timepoints over six years, children with NF1 and plexiform neurofibromas (PNs) completed Woodcock-Johnson tests of writing mechanics (Spelling, Punctuation & Capitalization, handwriting), written expression of ideas (Writing Samples), writing speed (Writing Fluency), and tests of general cognitive ability, executive function, memory, and attention. Children (N = 76, mean age = 12.8 ± 3.4 years) completed at least one baseline writing subtest. Overall writing scores were in the Average range (M = 93.4, SD = 17.4), but lower than population norms (p = 0.002). Scores were highest on Writing Samples (M = 95.2, SD = 17.3), and lowest for Punctuation & Capitalization (M = 87.9, SD = 18.8, p = 0.034). Writing scores were mostly stable over time. Nonverbal reasoning was related to some tests of writing mechanics and written expression of ideas. Short-term memory and inattention explained additional variance in Writing Samples and Spelling. Poor handwriting was associated with writing content beyond the impact of cognitive factors. Children with NF1 and PNs may benefit from early screening and writing support. Interventions should address the contribution of both cognitive and handwriting difficulties in written language.

Biallelic NF1 inactivation in high grade serous ovarian cancers from patients with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a multisystem disorder caused by germline heterozygous NF1 loss-of-function variants. The NF1 gene encodes neurofibromin, a RAS GTPase-activating protein, which functions by down-regulating RAS/RAF/MAPK-signalling pathways. Somatic NF1 aberrations frequently occur in sporadic ovarian cancer (OC), but the incidence of OC in NF1 patients is rare. Here we report the germline and somatic findings for two unrelated patients with NF1 and high-grade serous OC. Germline testing revealed a heterozygous NF1 pathogenic variant in each patient, c.7096_7101del (p.Asn2366_Phe2367del) and c.964delA (p.Ile322Leufs*54), respectively. No germline variants in well-established OC predisposition genes were detected, including BRCA1 and BRCA2. Tumor loss-of-heterozygosity analysis demonstrated loss of the wild type NF1 allele for both patients. Biallelic NF1 inactivation occurs as part of OC pathogenesis in NF1 patients. Although the penetrance of NF1-associated OC is insufficient to warrant risk-reducing interventions, our findings highlight the potential for therapies targeting the RAS/RAF/MAPK-signalling pathway for these cases.

The development of the PlexiQoL: A patient-reported outcome measure for adults with neurofibromatosis type 1-associated plexiform neurofibromas

Background

To develop and validate a patient‐reported outcome (PRO) measure of quality of life (QoL), specific to patients with Neurofibromatosis Type 1 (NF1)‐associated plexiform neurofibromas (pNFs), suitable for use in clinical efficacy trials. The study was conducted in parallel in the UK and US.

Methods

Qualitative interviews were conducted with patients to generate questionnaire content. Face and content validity of the draft scale was assessed by cognitive debriefing interviews (CDIs). A postal validation survey was conducted to identify the final version of the questionnaire (the PlexiQoL), establish its unidimensionality, and assess its psychometric properties.

Results

Thematic analysis was performed on 42 interview transcripts. Thirty‐one CDIs revealed that patients found the draft scale to be comprehensible, relevant, and easy to complete. The postal validation survey was completed by 273 patients. Rasch analysis identified an 18‐item unidimensional scale that showed excellent internal consistency, reproducibility, and sensitivity to differences in patient‐perceived pNF severity, general health, and the use of pain medication.

Conclusions

The PlexiQoL is the first disease‐specific PRO assessing the ability of adults with NF‐1 associated pNFs to meet their basic human needs. Clinical trials are planned to assess the sensitivity to change of the PlexiQoL in people undergoing treatment for pNFs.

Neurofibromatosis 1 French national guidelines based on an extensive literature review since 1966

Neurofibromatosis type 1 is a relatively common genetic disease, with a prevalence ranging between 1/3000 and 1/6000 people worldwide. The disease affects multiple systems with cutaneous, neurologic, and orthopedic as major manifestations which lead to significant morbidity or mortality. Indeed, NF1 patients are at an increased risk of malignancy and have a life expectancy about 10-15 years shorter than the general population. The mainstay of management of NF1 is a patient-centered longitudinal care with age-specific monitoring of clinical manifestations, aiming at the early recognition and symptomatic treatment of complications as they occur. Protocole national de diagnostic et de soins (PNDS) are mandatory French clinical practice guidelines for rare diseases required by the French national plan for rare diseases. Their purpose is to provide health care professionals with guidance regarding the optimal diagnostic and therapeutic management of patients affected with a rare disease; and thus, harmonizing their management nationwide. PNDS are usually developed through a critical literature review and a multidisciplinary expert consensus. The purpose of this article is to present the French guidelines on NF1, making them even more available to the international medical community. We further dwelled on the emerging new evidence that might have therapeutic potential or a strong impact on NF1 management in the coming feature. Given the complexity of the disease, the management of children and adults with NF1 entails the full complement healthcare providers and communication among the various specialties.

Pigmented (melanotic) diffuse neurofibroma of the back in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a tumor predisposition disease. Multiple neurofibromas are among the characteristic tumors of NF1. The report describes the diagnosis and treatment of a large spinal neurofibroma in a NF1 patient. The tumor showed a striking pigmentation and was diagnosed as pigmented (melanotic) neurofibroma. The distinction between this rare tumor variant and other pigmented tumors, especially malignant melanoma, is of primary importance.

Moyamoya syndrome associated with neurofibromatosis type 1 in a pediatric patient

Neurofibromatosis type 1 is a multisystem genetic disease of autosomal dominant transmission that reveals important cutaneous manifestations such as café-au-lait spots, multiple neurofibromas, and ephelides in skin fold areas, as well as hamartomatous lesions in the eyes, bones, glands, and central nervous system. Moyamoya disease is a rare progressive vaso-occlusive disorder that occurs with important ischemic cerebrovascular events. Despite the rarity of this association in childhood, children diagnosed with neurofibromatosis type 1 and focal neurologic symptoms should be investigated for moyamoya syndrome. The present study reports the case of a pediatric patient with a rapidly progressive cerebrovascular accident and a late diagnosis of Neurofibromatosis type 1 associated with moyamoya disease.

Preclinical Evidence for the Use of Sunitinib Malate in the Treatment of Plexiform Neurofibromas

PURPOSE

Plexiform neurofibromas (pNF) are pathognomonic nerve and soft tissue tumors of neurofibromatosis type I (NF1), which are highly resistant to conventional chemotherapy and associated with significant morbidity/mortality. Disruption of aberrant SCF/c-Kit signaling emanating from the pNF microenvironment induced the first ever objective therapeutic responses in a recent phase 2 trial. Sunitinib malate is a potent, highly selective RTK inhibitor with activity against c-Kit, PDGFR, and VEGFR, which have also been implicated in the pathogenesis of these lesions. Here, we evaluate the efficacy of sunitinib malate in a preclinical Krox20;Nf1(flox/-) pNF murine model.

EXPERIMENTAL DESIGN

Proliferation, β-hexosaminidase release (degranulation), and Erk1/2 phosphorylation were assessed in sunitinib treated Nf1(+/-) mast cells and fibroblasts, respectively. Krox20;Nf1(flox/-) mice with established pNF were treated sunitinib or PBS-vehicle control for a duration of 12 weeks. pNF metabolic activity was monitored by serial [(18)F]DG-PET/CT imaging.

RESULTS

Sunitinib suppressed multiple in vitro gain-in-functions of Nf1(+/-) mast cells and fibroblasts and attenuated Erk1/2 phosphorylation. Sunitinib treated Krox20;Nf1(flox/-) mice exhibited significant reductions in pNF size, tumor number, and FDG uptake compared to control mice. Histopathology revealed reduced tumor cellularity and infiltrating mast cells, markedly diminished collagen deposition, and increased cellular apoptosis in sunitinib treated pNF.

CONCLUSIONS

Collectively, these results demonstrate the efficacy of sunitinib in reducing tumor burden in Krox20;Nf1(flox/-) mice. These preclinical findings demonstrate the utility of inhibiting multiple RTKs in pNF and provide insights into the design of future clinical trials.

Malignant peripheral nerve sheath tumor in neurobifromatosis type-1: two case reports

Introduction

Malignant peripheral nerve sheath tumors are rare soft tissue sarcomas. They are considered to carry a poor prognosis with current therapeutic approaches. Successful treatment depends on a multimodal approach.

Case presentation

The authors report two cases with malignant peripheral nerve sheath tumors arising from pre-existing neurofibromas in the grounds of neurofibromatis-type I. Complete surgical removal of all lesions is considered before and after induction chemotherapy. Correlation of the response to chemotherapy in the context of the immuno-histopathological features of the tumors is also discussed with reference to the existing literature.

Conclusion

A need for a multidisciplinary approach with chemotherapy, surgery and radiotherapy is anticipated in the management of malignant peripheral nerve sheath tumors as described in these two reported cases. It is felt that further research on the molecular aspects of malignant peripheral nerve sheath tumors and neurofibromatis-type I will optimize treatment strategies in the future.