Therapeutic Strategies for Gliomas Associated With Cancer Predisposition Syndromes.

PURPOSE: The purpose of this article was to provide an overview of syndromic gliomas. DESIGN: The authors conducted a nonsystematic literature review. RESULTS: Cancer predisposition syndromes (CPSs) are genetic conditions that increase one's risk for certain types of cancer compared with the general population. Syndromes that can predispose one to developing gliomas include neurofibromatosis, Li-Fraumeni syndrome, Lynch syndrome, and tuberous sclerosis complex. The standard treatment for sporadic glioma may involve resection, radiation therapy, and/or alkylating chemotherapy. However, DNA-damaging approaches, such as radiation and alkylating agents, may increase the risk of secondary malignancies and other complications in patients with CPSs. In some cases, depending on genetic aberrations, targeted therapies or immunotherapeutic approaches may be considered. Data on clinical characteristics, therapeutic strategies, and prognosis of syndromic gliomas remain limited. CONCLUSION: In this review, we provide an overview of syndromic gliomas with a focus on management for patients with CPSs and the role of novel treatments that can be considered.

Experimental models of undifferentiated pleomorphic sarcoma and malignant peripheral nerve sheath tumor.

Undifferentiated pleomorphic sarcoma (UPS) and malignant peripheral nerve sheath tumor (MPNST) are aggressive soft tissue sarcomas that do not respond well to current treatment modalities. The limited availability of UPS and MPNST cell lines makes it challenging to identify potential therapeutic targets in a laboratory setting. Understanding the urgent need for improved treatments for these tumors and the limited cellular models available, we generated additional cell lines to study these rare cancers. Patient-derived tumors were used to establish 4 new UPS models, including one radiation-associated UPS-UPS271.1, UPS511, UPS0103, and RIS620, one unclassified spindle cell sarcoma-USC060.1, and 3 new models of MPNST-MPNST007, MPNST3813E, and MPNST4970. This study examined the utility of the new cell lines as sarcoma models by assessing their tumorigenic potential and mutation status for known sarcoma-related genes. All the cell lines formed colonies and migrated in vitro. The in vivo tumorigenic potential of the cell lines and corresponding xenografts was determined by subcutaneous injection or xenograft re-passaging into immunocompromised mice. USC060.1 and UPS511 cells formed tumors in mice upon subcutaneous injection. UPS0103 and RIS620 tumor implants formed tumors in vivo, as did MPNST007 and MPNST3813E tumor implants. Targeted sequencing analysis of a panel of genes frequently mutated in sarcomas identified TP53, RB1, and ATRX mutations in a subset of the cell lines. These new cellular models provide the scientific community with powerful tools for detailed studies of tumorigenesis and for investigating novel therapies for UPS and MPNST.

Enhancer reprogramming in PRC2-deficient malignant peripheral nerve sheath tumors induces a targetable de-differentiated state.

Malignant peripheral nerve sheath tumors (MPNSTs) are soft tissue sarcomas that frequently harbor genetic alterations in polycomb repressor complex 2 (PRC2) components-SUZ12 and EED. Here, we show that PRC2 loss confers a dedifferentiated early neural-crest phenotype which is exclusive to PRC2-mutant MPNSTs and not a feature of neurofibromas. Neural crest phenotype in PRC2 mutant MPNSTs was validated via cross-species comparative analysis using spontaneous and transgenic MPNST models. Systematic chromatin state profiling of the MPNST cells showed extensive epigenomic reprogramming or chromatin states associated with PRC2 loss and identified gains of active enhancer states/super-enhancers on early neural crest regulators in PRC2-mutant conditions around genomic loci that harbored repressed/poised states in PRC2-WT MPNST cells. Consistently, inverse correlation between H3K27me3 loss and H3K27Ac gain was noted in MPNSTs. Epigenetic editing experiments established functional roles for enhancer gains on DLX5-a key regulator of neural crest phenotype. Consistently, blockade of enhancer activity by bromodomain inhibitors specifically suppressed this neural crest phenotype and tumor burden in PRC2-mutant PDXs. Together, these findings reveal accumulation of dedifferentiated neural crest like state in PRC2-mutant MPNSTs that can be targeted by enhancer blockade.

Immune Effector Cell Associated Neurotoxicity (ICANS) in Pediatric and Young Adult Patients Following Chimeric Antigen Receptor (CAR) T-Cell Therapy: Can We Optimize Early Diagnosis?

The Cornell Assessment for Pediatric Delirium (CAPD) was first proposed by the Pediatric Acute Lung Injury and Sepsis Investigators Network-Stem Cell Transplantation and Cancer Immunotherapy Subgroup and MD Anderson CARTOX joint working committees, for detection of immune effector cell associated neurotoxicity (ICANS) in pediatric patients receiving chimeric antigen receptor (CAR) T-cell therapy. It was subsequently adopted by the American Society for Transplantation and Cellular Therapy. The utility of CAPD as a screening tool for early diagnosis of ICANS has not been fully characterized. We conducted a retrospective study of pediatric and young adult patients (n=15) receiving standard-of-care CAR T-cell products. Cytokine release syndrome (CRS) and ICANS occurred in 87% and 40% of patients, respectively. ICANS was associated with significantly higher peaks of serum ferritin. A change in CAPD from a prior baseline was noted in 60% of patients with ICANS, 24-72 h prior to diagnosis of ICANS. The median change from baseline to maximum CAPD score of patients who developed ICANS versus those who did not was 13 versus 3, respectively (p=0.0004). Changes in CAPD score from baseline may be the earliest indicator of ICANS among pediatric and young adult patients which may warrant closer monitoring, with more frequent CAPD assessments.

Comparison of Cancer Prevalence in Patients With Neurofibromatosis Type 1 at an Academic Cancer Center vs in the General Population From 1985 to 2020.

Importance: Neurofibromatosis type 1 (NF1) is a complex genetic disorder that is associated with not only neurofibromas, but also an increased susceptibility to other neoplasms. Objective: To evaluate the prevalence of neoplasia and outcomes among patients with NF1. Design, Setting, and Participants: This cohort study was conducted among patients with NF1 at a single academic cancer center from 1985 to 2020 with median (range) follow-up of 2.9 years (36 days to 30.5 years). Of 2427 patients evaluated for NF1, 1607 patients who met the National Institutes of Health consensus criteria for NF1 were included. This group was compared with estimates from Surveillance, Epidemiology, and End Results (SEER) Cancer Statistics Review 1975 to 2015 and SEER participants database unless otherwise specified. Data were analyzed from August 2018 to March 2020. Main Outcomes and Measures: Disease-specific survival (DSS) was measured from diagnosis date to date of neoplasm-specific death or censorship and calculated using the Kaplan-Meier method. Survival curves were compared using the log-rank test. Deaths from disease were considered a DSS end point; other deaths were considered censored observations. Secondary outcome measures were comparisons of (1) overall survival of patients with NF1 with neurofibroma neoplasms vs those without nonneurofibroma neoplasms, (2) neoplasm prevalence in the NF1 group vs general population estimates, and (3) age at diagnosis in the NF1 group vs general population estimates for the most common neoplasms in the NF1 group. Results: Among 1607 patients with NF1, the median (range) age at initial visit was 19 years (1 month to 83 years) and 840 (52.3%) were female patients. Among 666 patients who developed other neoplasms in addition to neurofibromas (41.4%), 295 patients (18.4%) developed glioma and 243 patients (15.1%) developed malignant peripheral nerve sheath tumor (MPNST), the most common neoplasms. Patients with NF1, compared with the general population, developed several neoplasms at a younger mean (SD) age (low-grade glioma: 12.98 [11.09] years vs 37.76 [24.53] years; P < .0001; high-grade glioma [HGG]: 27.31 [15.59] years vs 58.42 [19.09] years; P < .0001; MPNST: 33.88 [14.80] years vs 47.06 [20.76] years; P < .0001; breast cancer: 46.61 [9.94] years vs 61.71 [13.85] years; P < .0001). Patients with NF1 developed neoplasms more frequently compared with the general population (odds ratio, 9.5; 95% CI, 8.5-10.5; P < .0001). Among patients with NF1, significantly lower 5-year DSS rates were found among those with undifferentiated pleomorphic sarcoma (1 of 5 patients [20.0%]), HGG (8 of 34 patients [23.1%]), MPNST (72 of 228 patients [31.6%]), ovarian carcinoma (4 of 7 patients [57.1%]), and melanoma (8 of 12 patients [66.7%]) compared with those who had neoplasms classified as other (110 of 119 patients [92.4%]) (all P < .001) . Conclusions and Relevance: This cohort study found that among patients with NF1, those who developed undifferentiated pleomorphic sarcoma, HGG, MPNST, ovarian carcinoma, or melanoma had significantly lower DSS rates compared with those who developed other neoplasms. This study also found that patients with NF1 developed some neoplasms more frequently and at a younger age compared with individuals without NF1. HGGs and MPNST were noteworthy causes of death among patients NF1. This information may be useful for NF1 patient counseling and follow-up.

Surgical treatment of common peroneal neuropathy in schwannomatosis: illustrative cases.

BACKGROUND: Neurofibromatosis syndromes such as neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis often result in painful symptoms related to tumor burden. OBSERVATIONS: Painful symptoms classically associated with common points of peripheral nerve entrapment, such as common peroneal neuropathy at the fibular tunnel, may present in patients both with and without focal tumor involvement. LESSONS: Surgical decompression at the point of entrapment, with or without resection of tumor, may provide symptomatic relief. Examples of surgical decompression at the point of entrapment, both with and without resection of tumor, are presented.

Coincidental Expression of Classic Hodgkin Lymphoma and Neurofibromatosis Type I and Literature Review.

Neurofibromatosis Type 1 (NF1) is a genetic disorder with an incidence of 1 in 2600 to 3000 individuals. It is a clinical diagnosis characterized by café-au-lait macules, neurofibromas, and axillary and/or groin freckling. Because of genetic mutations in the NF1 gene affecting the Ras/mitogen-activated protein kinase pathway, there is also risk of associated soft tissue sarcomas and hematologic malignancies. However, reports of classic Hodgkin lymphoma in patients with NF1 are sparse. We report an adolescent with NF1 who developed classic Hodgkin lymphoma. Although there is an unclear association between mutations in the NF1 gene and classic Hodgkin lymphoma, further studies are warranted.

Management guidelines for paediatric patients receiving chimeric antigen receptor T cell therapy.

In 2017, an autologous chimeric antigen receptor (CAR) T cell therapy indicated for children and young adults with relapsed and/or refractory CD19+ acute lymphoblastic leukaemia became the first gene therapy to be approved in the USA. This innovative form of cellular immunotherapy has been associated with remarkable response rates but is also associated with unique and often severe toxicities, which can lead to rapid cardiorespiratory and/or neurological deterioration. Multidisciplinary medical vigilance and the requisite health-care infrastructure are imperative to ensuring optimal patient outcomes, especially as these therapies transition from research protocols to standard care. Herein, authors representing the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network Hematopoietic Stem Cell Transplantation (HSCT) Subgroup and the MD Anderson Cancer Center CAR T Cell Therapy-Associated Toxicity (CARTOX) Program have collaborated to provide comprehensive consensus guidelines on the care of children receiving CAR T cell therapy.

Treatment of Disfiguring Cutaneous Lesions in Neurofibromatosis-1 with Everolimus: A Phase II, Open-Label, Single-Arm Trial.

BACKGROUND: Cutaneous neurofibromas cause disfigurement and discomfort in individuals with neurofibromatosis type 1 (NF-1). METHODS: The primary objective of this phase II, open-label, single-arm trial was to assess whether orally administered everolimus reduced the surface volume of cutaneous neurofibromas in patients with NF-1. RESULTS: Of 22 patients who took the study drug, 17 completed the trial; 5 patients withdrew due to adverse events. Sixteen patients had photographs of sufficient quality for assessment of the primary outcome. A significant reduction in lesion surface volume, defined as an end of trial volume > 2 standard errors (SE) less than baseline volume, was observed for 4/31 lesions (13%) from 3/16 patients (19%). Additionally, a statistically significant absolute change in average height for paired lesions was observed (p = 0.048). Although not a prespecified outcome measure, a dramatic reduction in the size of 3 large plexiform neurofibromas with a cutaneous component was also noted and documented by measurement of maximum circumference or magnetic resonance imaging-based volumetric analysis. Adverse events were common in this trial, but no serious adverse events occurred. CONCLUSIONS: Although this was a small, exploratory trial that was not powered for significance, the reduction in surface volume observed in this study is noteworthy assuming that the natural course for untreated lesions is to maintain or increase in volume. Future studies are needed with larger study populations that incorporate longer durations of treatment and better standardization of volumetric measurements. Trial Registration ClinicalTrials.gov Identifier: NCT02332902.

Efficacy and Safety of Topical Rapamycin in Patients With Facial Angiofibromas Secondary to Tuberous Sclerosis Complex: The TREATMENT Randomized Clinical Trial.

Importance: Facial angiofibromas occur in approximately 75% of individuals with tuberous sclerosis complex (TSC), causing substantial morbidity and disfigurement. Current therapies are partially effective, uncomfortable, produce scarring, and need repeating to treat recurrence. Objective: To evaluate the efficacy and safety of topical rapamycin for TSC-related facial angiofibromas. Design, Setting, and Participants: This prospective, multicenter, randomized, double-blind, vehicle-controlled trial with 6 monthly clinic visits enrolled 179 patients with TSC-related facial angiofibromas not treated within 6 months from May 2012 to March 2014 in 9 clinical sites in the United States and 1 in Australia. Interventions: Patients were randomized (1:1:1) to topical formulation containing 0.3 g per 30 g (1%) rapamycin, 0.03 g per 30 g (0.1%) rapamycin, or vehicle alone. Participants applied 1.0 mL to designated areas daily at bedtime. Main Outcomes and Measures: Angiofibroma Grading Scale (AGS) change from baseline scored from photographs by independent masked dermatologists. Safety analyses included adverse events (AEs) and serum rapamycin levels. Results: All 179 patients randomized (99 [55.3%] female) comprised the primary analysis population (59 in the 1% rapamycin group, 63 in the 0.1% rapamycin group, and 57 in the vehicle-only group). The mean age was 20.5 years (range 3-61 years). Clinically meaningful and statistically significant improvement in facial angiofibromas was observed for both 1% and 0.1% rapamycin relative to the vehicle-only control group, and for 1% vs 0.1% rapamycin, with most of the improvement realized within the first month. At 6 months, AGS mean improvement for 1% rapamycin was 16.7 points compared with 11.0 for 0.1% rapamycin and 2.1 points for vehicle only (P < .001 for 1% and 0.1% vs vehicle only). Compared with baseline, end-of-treatment photos were rated "better" for 81.8% of patients in the 1% rapamycin group, compared with 65.5% for those in the 0.1% rapamycin group and 25.5% for those in the vehicle-only group (P < .001, all 3 pairwise comparisons). Topical rapamycin was generally well-tolerated, with no measurable systemic absorption. Apparent drug-related adverse effects were limited to 10% or less incidence of application site discomfort and/or pain, pruritus, erythema, and irritation. Nearly all AEs were mild, with no drug-related moderate, severe, or serious events. Conclusions and Relevance: Topical rapamycin appears effective and safe for treatment of TSC-related facial angiofibromas. In this trial, the preferred dose was 1% once daily. Future studies are needed to evaluate prophylactic, early, and long-term use of topical rapamycin, durability of response, and combination therapy with oral mammalian target of rapamycin (mTOR) inhibitors. Trial Registration: ClinicalTrials.gov Identifier: NCT01526356.

Prognostic Role of Conventional and Dynamic Contrast-Enhanced MRI in Optic Pathway Gliomas.

BACKGROUND AND PURPOSE: The natural history of optic pathway glioma (OPG) is highly variable and unpredictable. We present a pilot study of the prognostic role of conventional and dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) in the evaluation of OPG. METHODS: We retrospectively reviewed 17 patients with 20 pretreatment OPG lesions who underwent conventional and DCE MRI between January 2010 and December 2016. Conventional MRI was evaluated for enhancement pattern, cystic component, optic nerve tortuosity, optic nerve dural ectasia, and optic nerve perineural thickening. The DCE MRI data were analyzed for quantitative parameters using the two-compartment pharmacokinetic model (Ktrans , kep , and ve ) and for semiquantitative parameters based on time-signal intensity curve (AUC60 , peak, and wash-in). The results were compared with the clinically progressive or nonprogressive tumor. RESULTS: Five progressive OPGs and 15 nonprogressive OPGs were included. Conventional MRI findings of diffuse enhancement and cystic component were significantly correlated with progressive OPGs (both P = .01). Conventional MRI yielded sensitivity of 60%, specificity of 100%, and accuracy of 90%. Ktrans , kep , and ve as well as AUC60 , peak, and wash-in were significantly higher in progressive OPGs (P < .05). Using DCE MRI increased diagnostic performance up to a sensitivity of 100%, specificity of 93%, and accuracy of 95%. CONCLUSION: DCE MRI accurately distinguished progressive and nonprogressive OPGs, with high sensitivities and specificities. DCE MRI has a significant prognostic role in predicting progressive OPGs, thus making it useful for the identification of patients who need close clinical and imaging follow-up.

Patterns of recurrence and survival in sporadic, neurofibromatosis Type 1-associated, and radiation-associated malignant peripheral nerve sheath tumors.

OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) are an aggressive group of soft tissue sarcomas that can arise sporadically, in the context of neurofibromatosis Type 1 (NF1) or at a site of prior irradiation. Large series profiling the features and outcomes of sporadic, NF1-associated, and radiation-associated MPNSTs are limited. The goal of this study was to elucidate differences between MPNST etiologies in a large single-institution retrospective study. METHODS Patients (n = 317) were identified through the tumor registry of The University of Texas MD Anderson Cancer Center. Clinicopathological features were retrospectively collected. Features were compared among MPNST subtypes for patients who had sufficient clinical history (n = 289), and clinicopathological features were used to identify adverse predictors of recurrence and survival outcomes. RESULTS Five-year local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), and disease-specific survival (DSS) estimates were 56.6%, 49.6%, and 53.6%, respectively, for the high-grade MPNST cohort. Five-year DSS was lower in NF1-associated and radiation-associated MPNST than in sporadic MPNST (52%, 47%, and 67%, respectively, p = 0.140). Patients with radiation-associated MPNST had worse 5-year LRFS than those with the sporadic and NF1-associated subtypes (RT-associated vs sporadic, p = 0.010; RT-associated vs NF1-associated, p = 0.232). Truncally located tumors, positive surgical margins, local recurrence, and metastasis were predictors of adverse DSS in multivariate analysis. CONCLUSIONS Radiation-associated MPNSTs are associated with poorer local recurrence-free and disease-specific survival than sporadic and NF1-associated tumors. NF1-associated MPNSTs may have worse survival outcomes owing to large tumor size, compromising truncal location, and lower rate of negative resection margins compared with sporadic tumors.

Neurofibromas of the Phrenic Nerve: A Case Report and Review of the Literature.

BACKGROUND: Phrenic neurofibromas are a rare pathologic entity, with 9 cases described in the English literature. They may occur in conjunction with or independently of neurofibromatosis type 1. Phrenic neurofibromas pose distinct therapeutic challenges compared with the more common phrenic schwannoma. We describe here a 12-year-old boy with neurofibroma of the left phrenic nerve presenting as dextroposition of the heart after paralysis of the left hemidiaphragm allowed herniation of abdominal contents into the left hemithorax and displaced the heart. METHOD: Surgical resection of the tumor followed by diaphragmatic plication was performed to assess its degree of malignancy, reduce abdominal herniation, and improve lung capacity. RESULTS: The operation markedly improved his hemidiaphragmatic elevation. CONCLUSIONS: The spectrum of management options ranges from conservative surveillance to open thoracic surgery. Functional preservation of the phrenic nerve is technically challenging, and although phrenic neurofibromas often present with absent function that cannot be recovered, surgical intervention can be fruitful in restoring lung capacity through diaphragmatic reconstruction.

Poly (ADP) ribose polymerase inhibition: A potential treatment of malignant peripheral nerve sheath tumor.

Poly (ADP) ribose polymerase (PARP) inhibitors, first evaluated nearly a decade ago, are primarily used in malignancies with known defects in DNA repair genes, such as alterations in breast cancer, early onset 1/2 (BRCA1/2). While no specific mutations in BRCA1/2 have been reported in malignant peripheral nerve sheath tumors (MPNSTs), MPNST cells could be effectively targeted with a PARP inhibitor to drive cells to synthetic lethality due to their complex karyotype and high level of inherent genomic instability. In this study, we assessed the expression levels of PARP1 and PARP2 in MPNST patient tumor samples and correlated these findings with overall survival. We also determined the level of PARP activity in MPNST cell lines. In addition, we evaluated the efficacy of the PARP inhibitor AZD2281 (Olaparib) in MPNST cell lines. We observed decreased MPNST cell proliferation and enhanced apoptosis in vitro at doses similar to, or less than, the doses used in cell lines with established defective DNA repair genes. Furthermore, AZD2281 significantly reduced local growth of MPNST xenografts, decreased the development of macroscopic lung metastases, and increased survival of mice with metastatic disease. Our results suggest that AZD2281 could be an effective therapeutic option in MPNST and should be further investigated for its potential clinical use in this malignancy.

Prolonged survival in adult neurofibromatosis type I patients with recurrent high-grade gliomas treated with bevacizumab.

Astrocytic tumors, especially optic pathway pilocytic astrocytomas, are common in pediatric NF1 patients. High-grade gliomas (HGGs) appear to be rare in adult and pediatric NF1 patients. This is a series of five consecutive, adult NF1 patients with recurrent HGGs treated at The University of Texas MD Anderson Cancer Center. Four patients met consensus clinical criteria for NF1 and one patient had presumed segmental NF1. Three patients had glioblastomas, one gliosarcoma, and one progressive, enhancing optic pathway glioma which was not biopsied. Two tumors had molecular testing performed; both were IDH wild type and activating oncogene mutations (1 BRAFV600E and 1 PIK3CA mutation) were found in these tumors. All five patients received bevacizumab-containing regimens at tumor recurrence. The median number of 4-week cycles of bevacizumab was 20. All five patients experienced prolonged post-recurrence survival following bevacizumab treatment ranging from ten to 72 months. The median overall survival from HGG diagnosis was 72.6 months with three patients alive and progression free at last follow-up. Three out of five patients developed vascular complications leading to bevacizumab discontinuation. In this case series, adult NF1 patients with recurrent HGGs had prolonged, post-recurrence survival after treatment with bevacizumab-containing regimens. Based on these results, further study of antiangiogenic therapy in NF1 patients with HGGs and bevacizumab-response in sporadic HGG patients with NF1-mutated tumors is warranted.

The value of ¹8F-FDG PET/CT in the management of malignant peripheral nerve sheath tumors.

PURPOSE: Our objective was to determine how positron emission tomography (PET)/CT had been used in the clinical treatment of malignant peripheral nerve sheath tumor (MPNST) patients at The University of Texas MD Anderson Cancer Center. METHODS: We reviewed a database of MPNST patients referred to MD Anderson Cancer Center during 1995-2011. We enrolled 47 patients who underwent PET/CT imaging. Disease stage was based on conventional imaging and PET/CT findings using National Comprehensive Cancer Network (NCCN) guidelines. Treatment strategies based on PET/CT and conventional imaging were determined by chart review. The maximum and mean standardized uptake values (SUVmax, SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), change in SUVmax, change in MTV, and change in TLG were calculated from the PET/CT studies before and after treatment. Response prediction was based on imaging studies performed before and after therapy and categorized as positive or negative for residual tumor. Clinical outcome was determined from chart review. RESULTS: PET/CT was performed for staging in 16 patients, for restaging in 29 patients, and for surveillance in 2 patients. Of the patients, 88 % were correctly staged with PET/CT, whereas 75 % were correctly staged with conventional imaging. The sensitivity to detect local recurrence and distant metastasis at restaging was 100 and 100 % for PET/CT compared to 86 and 83 % for conventional imaging, respectively. PET/CT findings resulted in treatment changes in 31 % (5/16) and 14 % (4/29) of patients at staging and restaging, respectively. Recurrence, MTV, and TLG were prognostic factors for survival, whereas SUVmax and SUVmean were not predictive. For 21 patients who had imaging studies performed both before and after treatment, PET/CT was better at predicting outcome (overall survival, progression-free survival) than conventional imaging. A decreasing SUVmax ≥ 30 % and decrease in TLG and MTV were significant predictors for overall and progression-free survival. CONCLUSION: PET/CT is valuable in MPNST management because of its high accuracy in staging and high sensitivity and accuracy in restaging as well as improvements in treatment planning. MTV from baseline staging studies is predictive of survival. Additionally, change in SUVmax, TLG, and MTV accurately predicted outcomes after treatment.

Germline loss-of-function mutations in LZTR1 predispose to an inherited disorder of multiple schwannomas.

Constitutional SMARCB1 mutations at 22q11.23 have been found in ∼50% of familial and <10% of sporadic schwannomatosis cases. We sequenced highly conserved regions along 22q from eight individuals with schwannomatosis whose schwannomas involved somatic loss of one copy of 22q, encompassing SMARCB1 and NF2, with a different somatic mutation of the other NF2 allele in every schwannoma but no mutation of the remaining SMARCB1 allele in blood and tumor samples. LZTR1 germline mutations were identified in seven of the eight cases. LZTR1 sequencing in 12 further cases with the same molecular signature identified 9 additional germline mutations. Loss of heterozygosity with retention of an LZTR1 mutation was present in all 25 schwannomas studied. Mutations segregated with disease in all available affected first-degree relatives, although four asymptomatic parents also carried an LZTR1 mutation. Our findings identify LZTR1 as a gene predisposing to an autosomal dominant inherited disorder of multiple schwannomas in ∼80% of 22q-related schwannomatosis cases lacking mutation in SMARCB1.

Multidetector CT with 3-dimensional volume rendering in the evaluation of the spine in patients with Neurofibromatosis type 1: a retrospective review in 73 patients.

INTRODUCTION: Neurofibromatosis type 1 (NF-1) may involve the spine as various abnormalities including bony dysplasia, scoliosis, and nerve sheath tumors. Surgery may be performed for stabilization of the spine. We have seen an increase in requests for multidetector CT (MDCT) imaging with the (three-dimensional) 3D-volume rendered (VR) images in patients evaluated at our institution. We, therefore, investigated how MDCT could be best utilized in this patient population. METHODS: Seventy-three patients with NF-1 were identified in whom MDCT imaging was performed for diagnostic, pre-operative, or post-operative evaluation of spinal abnormalities. True axial source images and two dimensional (2D) orthogonal reconstructed MDCT images, as well as the VR images, were compared with plain radiographs and MRI. In addition, the MDCT study was compared to the VR images. These studies were reviewed to compare assessment of A) bony abnormalities such as remodeling from dural ectasia, dysplasia, and fusion, B) abnormal spinal curvature, C) nerve sheath tumors, and D) surgical instrumentation. RESULTS: When compared to plain radiographs, the MDCT and VR images were rated as helpful for evaluating the abnormalities of the spine in 19 of 24 patients for a total of 30 findings. This included the following categories A) (n = 6), B) (n = 5), C) (n = 7), and D) (n = 12). Compared to MR, the MDCT and VR study was helpful in evaluating the findings of NF-1 in 24 of 36 patients for a total of 40 findings. This included the following categories A) (n = 12), B) (n = 10), C) (n = 3), and D) (n = 15). When the VR images were compared to the orthogonal MDCT, the VR images was rated as helpful in 41 of 73 patients for a total of 60 findings, including the following categories: A) (n = 11), B) (n = 24), C) (n = 0), and D) (n = 25). CONCLUSION: MDCT has distinct advantages over plain radiographs and MR imaging, and the VR images over MDCT in the evaluation of the spine in patients with NF-1, especially for the assessment of bony abnormalities, abnormal spinal curvature, and spinal instrumentation.

Binding partners for curcumin in human schwannoma cells: biologic implications.

Curcumin (diferuloylmethane) is a potent anti-inflammatory and anti-tumorigenic agent that has shown preclinical activity in diverse cancers. Curcumin up-regulates heat shock protein 70 (hsp70) mRNA in several different cancer cell lines. Hsp70 contributes to an escape from the apoptotic effects of curcumin by several different mechanisms including prevention of the release of apoptosis inducing factor from the mitochondria and inhibition of caspases 3 and 9. Previously we showed that the combination of curcumin plus a heat shock protein inhibitor was synergistic in its down-regulation of the proliferation of a human schwannoma cell line (HEI-193) harboring an NF2 mutation, possibly because curcumin up-regulated hsp70, which also binds merlin, the NF2 gene product. In order to determine if curcumin also interacts directly with hsp70 and to discover other binding partners of curcumin, we synthesized biotinylated curcumin (bio-curcumin) and treated HEI-193 schwannoma cells. Cell lysates were prepared and incubated with avidin-coated beads. Peptides pulled down from this reaction were sequenced and it was determined that biotinylated curcumin bound hsp70, hsp90, 3-phosphoglycerate dehydrogenase, and a ß-actin variant. These binding partners may serve to further elucidate the underlying mechanisms of curcumin's actions.

Combining curcumin (diferuloylmethane) and heat shock protein inhibition for neurofibromatosis 2 treatment: analysis of response and resistance pathways.

Neurofibromatosis type 2 (NF2) is a genetic condition characterized by inactivation of the NF2 tumor suppressor gene and the development of schwannomas. The NF2 gene product, merlin, is activated (dephosphorylated) by contact inhibition and promotes growth suppression. We investigated the effect of curcumin (diferuloylmethane), a molecule with anti-inflammatory and antitumorigenic properties, on human schwannoma cell growth and the regulation of merlin by curcumin in both NF2 cells and neuroblastoma (non-NF2) cells. Curcumin inhibited the growth of HEI-193 schwannoma cells in vitro and downregulated the phosphorylation of Akt and extracellular signal-regulated kinase 1/2. Curcumin also activated MYPT1-pp1δ (a merlin phosphatase), which was associated with dephosphorylation of merlin on serine 518, an event that results in the folding of merlin to its active conformation. In addition, curcumin induced apoptosis and generated reactive oxygen species in HEI-193 cells. Consequently, hsp70 was upregulated at the mRNA and protein levels, possibly serving as a mechanism of escape from curcumin-induced apoptosis and growth inhibition. Endogenous merlin and hsp70 proteins interacted in HEI-193 schwannoma and SK-N-AS neuroblastoma cells. The combination of curcumin and an hsp inhibitor synergistically suppressed schwannoma cell growth. Our results provide a rationale for combining curcumin and KNK437 in the treatment of NF2.