A systematic review and individual participant data meta-analysis of gonadal steroid hormone receptors in meningioma

OBJECTIVE

The relationship between patient and meningioma characteristics and hormone receptors (HRs) of progesterone, estrogen, and androgen remains poorly defined despite literature suggesting that meningiomas are sensitive to gonadal steroid hormones. Therefore, the authors sought to collect and compare data on this topic by performing a systematic review and meta-analysis of reported studies of HR status in meningiomas.

METHODS

A MEDLINE PubMed literature review conducted for articles published between January 1, 1951, and December 31, 2020, resulted in 634 unduplicated articles concerning meningiomas and HRs. There were 114 articles that met the criteria of detailed detection protocols for progesterone receptor (PR), estrogen receptor (ER), and/or androgen receptor (AR) using immunohistochemistry (IHC) or ligand-binding (LB) assays and simultaneous reporting of HR status with at least one variable among age, sex, histology, location, grade, or recurrence. Between-study heterogeneity and risk of bias were evaluated using graphical and statistical methods. The authors performed a multilevel meta-analysis using random-effects modeling on aggregated data (n = 4447) and individual participant data (n = 1363) with subgroup results summarized as pooled effects. A mixed-effects meta-regression using individual participant data was performed to analyze independently associated variables.

RESULTS

The 114 selected articles included data for 5810 patients with 6092 tumors analyzed to determine the expression of three HRs in human meningiomas: PRs, ARs, and ERs. The proportions of HR+ meningiomas were estimated to be 0.76 (95% CI 0.72-0.80) for PR+ and 0.50 (95% CI 0.33-0.66) for AR+ meningiomas. ER+ meningioma detection varied depending on the measurement method used and was 0.06 (95% CI 0.03-0.10) with IHC and 0.11 (95% CI 0.06-0.20) with LB assays. There were associations between age and PR and ER expression that varied between male and female patients. PR+ and AR+ were more common in female patients (OR 1.84, 95% CI 1.47-2.29 for PR and OR 4.16, 95% CI 1.62-10.68 for AR). Additionally, PR+ meningiomas were enriched in skull base locations (OR 1.89, 95% CI 1.03-3.48) and meningothelial histology (OR 1.86, 95% CI 1.23-2.81). A meta-regression showed that PR+ was independently associated with age (OR 1.11 95% CI 1.09-1.13; p < 0.0001) and WHO grade I tumors (OR 8.09, 95% CI 3.55-18.44; p < 0.0001). ER+ was negatively associated with meningothelial histology (OR 0.94, 95% CI 0.86-0.98; p = 0.044) and positively associated with convexity location (OR 1.12, 95% CI 1.05-1.18; p = 0.0003).

CONCLUSIONS

The association between HRs and meningioma features has been investigated but unexplained for decades. In this study the authors demonstrated that HR status has a strong association with known meningioma features, including WHO grade, age, female sex, histology, and anatomical location. Identifying these independent associations allows for a better understanding of meningioma heterogeneity and provides a foundation for revisiting targeted hormonal therapy in meningioma on the basis of proper patient stratification according to HR status.

Super-enhancer hijacking drives ectopic expression of hedgehog pathway ligands in meningiomas

Hedgehog signaling mediates embryologic development of the central nervous system and other tissues and is frequently hijacked by neoplasia to facilitate uncontrolled cellular proliferation. Meningiomas, the most common primary brain tumor, exhibit Hedgehog signaling activation in 6.5% of cases, triggered by recurrent mutations in pathway mediators such as SMO. In this study, we find 35.6% of meningiomas that lack previously known drivers acquired various types of somatic structural variations affecting chromosomes 2q35 and 7q36.3. These cases exhibit ectopic expression of Hedgehog ligands, IHH and SHH, respectively, resulting in Hedgehog signaling activation. Recurrent tandem duplications involving IHH permit de novo chromatin interactions between super-enhancers within DIRC3 and a locus containing IHH. Our work expands the landscape of meningioma molecular drivers and demonstrates enhancer hijacking of Hedgehog ligands as a route to activate this pathway  in neoplasia.

Hormone therapies in meningioma-where are we?

INTRODUCTION

Meningiomas are associated with several gonadal steroid hormone-related risk factors and demonstrate a predominance in females. These associations led to investigations of the role that hormones may have on meningioma growth and development. While it is now accepted that most meningiomas express progesterone and somatostatin receptors, the conclusion for other receptors has been less definitive.

METHODS

We performed a review of what is known regarding the relationship between hormones and meningiomas in the published literature. Furthermore, we reviewed clinical trials related to hormonal agents in meningiomas using MEDLINE PubMed, Scopus, and the NIH clinical trials database.

RESULTS

We identify that all steroid-hormone trials lacked receptor identification or positive receptor status in the majority of patients. In contrast, four out of five studies involving somatostatin analogs used positive receptor status as part of the inclusion criteria.

CONCLUSIONS

Several clinical trials have recently been completed or are now underway using somatostatin analogs in combination with other therapies that appear promising, but a reevaluation of hormone-based monotherapy is warranted. Synthesizing this evidence, we clarify the remaining questions and present future directions for the study of the biological role and therapeutic potential of hormones in meningioma and discuss how the stratification of patients using features such as grade, receptor status, and somatic mutations, might be used for future trials to select patients most likely to benefit from specific therapies.

PPIL4 is essential for brain angiogenesis and implicated in intracranial aneurysms in humans

Intracranial aneurysm (IA) rupture leads to subarachnoid hemorrhage, a sudden-onset disease that often causes death or severe disability. Although genome-wide association studies have identified common genetic variants that increase IA risk moderately, the contribution of variants with large effect remains poorly defined. Using whole-exome sequencing, we identified significant enrichment of rare, deleterious mutations in PPIL4, encoding peptidyl-prolyl cis-trans isomerase-like 4, in both familial and index IA cases. Ppil4 depletion in vertebrate models causes intracerebral hemorrhage, defects in cerebrovascular morphology and impaired Wnt signaling. Wild-type, but not IA-mutant, PPIL4 potentiates Wnt signaling by binding JMJD6, a known angiogenesis regulator and Wnt activator. These findings identify a novel PPIL4-dependent Wnt signaling mechanism involved in brain-specific angiogenesis and maintenance of cerebrovascular integrity and implicate PPIL4 gene mutations in the pathogenesis of IA.

DIAPH1 Variants in Non-East Asian Patients With Sporadic Moyamoya Disease

Importance

Moyamoya disease (MMD), a progressive vasculopathy leading to narrowing and ultimate occlusion of the intracranial internal carotid arteries, is a cause of childhood stroke. The cause of MMD is poorly understood, but genetic factors play a role. Several familial forms of MMD have been identified, but the cause of most cases remains elusive, especially among non-East Asian individuals.

Objective

To assess whether ultrarare de novo and rare, damaging transmitted variants with large effect sizes are associated with MMD risk.

Design, Setting, and Participants

A genetic association study was conducted using whole-exome sequencing case-parent MMD trios in a small discovery cohort collected over 3.5 years (2016-2019); data were analyzed in 2020. Medical records from US hospitals spanning a range of 1 month to 1.5 years were reviewed for phenotyping. Exomes from a larger validation cohort were analyzed to identify additional rare, large-effect variants in the top candidate gene. Participants included patients with MMD and, when available, their parents. All participants who met criteria and were presented with the option to join the study agreed to do so; none were excluded. Twenty-four probands (22 trios and 2 singletons) composed the discovery cohort, and 84 probands (29 trios and 55 singletons) composed the validation cohort.

Main Outcomes and Measures

Gene variants were identified and filtered using stringent criteria. Enrichment and case-control tests assessed gene-level variant burden. In silico modeling estimated the probability of variant association with protein structure. Integrative genomics assessed expression patterns of MMD risk genes derived from single-cell RNA sequencing data of human and mouse brain tissue.

Results

Of the 24 patients in the discovery cohort, 14 (58.3%) were men and 18 (75.0%) were of European ancestry. Three of 24 discovery cohort probands contained 2 do novo (1-tailed Poisson P = 1.1 × 10-6) and 1 rare, transmitted damaging variant (12.5% of cases) in DIAPH1 (mammalian diaphanous-1), a key regulator of actin remodeling in vascular cells and platelets. Four additional ultrarare damaging heterozygous DIAPH1 variants (3 unphased) were identified in 3 other patients in an 84-proband validation cohort (73.8% female, 77.4% European). All 6 patients were non-East Asian. Compound heterozygous variants were identified in ena/vasodilator-stimulated phosphoproteinlike protein EVL, a mammalian diaphanous-1 interactor that regulates actin polymerization. DIAPH1 and EVL mutant probands had severe, bilateral MMD associated with transfusion-dependent thrombocytopenia. DIAPH1 and other MMD risk genes are enriched in mural cells of midgestational human brain. The DIAPH1 coexpression network converges in vascular cell actin cytoskeleton regulatory pathways.

Conclusions and Relevance

These findings provide the largest collection to date of non-East Asian individuals with sporadic MMD harboring pathogenic variants in the same gene. The results suggest that DIAPH1 is a novel MMD risk gene and impaired vascular cell actin remodeling in MMD pathogenesis, with diagnostic and therapeutic ramifications.

Associations of meningioma molecular subgroup and tumor recurrence

BACKGROUND

We and others have identified mutually exclusive molecular subgroups of meningiomas; however, the implications of this classification for clinical prognostication remain unclear. Integrated genomic and epigenomic analyses implicate unique oncogenic processes associated with each subgroup, suggesting the potential for divergent clinical courses. The aim of this study was to understand the associated clinical outcomes of each subgroup, as this could optimize treatment for patients.

METHODS

We analyzed outcome data for 469 meningiomas of known molecular subgroup, including extent of resection, postoperative radiation, surveillance imaging, and time to recurrence, when applicable. Statistical relationships between outcome variables and subgroup were assessed. Features previously associated with recurrence were further investigated after stratification by subgroup. We used Kaplan-Meier analyses to compare progression-free survival, and identified factors significantly associated with recurrence using Cox proportional hazards modeling.

RESULTS

Meningioma molecular subgroups exhibited divergent clinical courses at 2 years of follow-up, with several aggressive subgroups (NF2, PI3K, HH, tumor necrosis factor receptor-associated factor 7 [TRAF7]) recurring at an average rate of 22 times higher than others (KLF4, POLR2A, SMARCB1). PI3K-activated tumors recurred earlier than other subgroups but had intermediate long-term outcome. Among low-grade tumors, HH and TRAF7 meningiomas exhibited elevated recurrence compared with other subgroups. Recurrence of NF2 tumors was associated with male sex, high grade, and elevated Ki-67. Multivariate analysis identified molecular subgroup as an independent predictor of recurrence, along with grade and previous recurrence.

CONCLUSION

We describe distinct clinical outcomes and recurrence rates associated with meningioma molecular subgroups. Our findings emphasize the importance of genomic characterization to guide postoperative management decisions for meningiomas.

Clinical and genomic factors associated with seizures in meningiomas

OBJECTIVE

The association of seizures with meningiomas is poorly understood. Moreover, any relationship between seizures and the underlying meningioma genomic subgroup has not been studied. Herein, the authors report on their experience with identifying clinical and genomic factors associated with preoperative and postoperative seizure presentation in meningioma patients.

METHODS

Clinical and genomic sequencing data on 394 patients surgically treated for meningioma at Yale New Haven Hospital were reviewed. Correlations between clinical, histological, or genomic variables and the occurrence of preoperative and postoperative seizures were analyzed. Logistic regression models were developed for assessing multiple risk factors for pre- and postoperative seizures. Mediation analyses were also conducted to investigate the causal pathways between genomic subgroups and seizures.

RESULTS

Seventeen percent of the cohort had presented with preoperative seizures. In a univariate analysis, patients with preoperative seizures were more likely to have tumors with a somatic NF2 mutation (p = 0.020), WHO grade II or III tumor (p = 0.029), atypical histology (p = 0.004), edema (p < 0.001), brain invasion (p = 0.009), and worse progression-free survival (HR 2.68, 95% CI 1.30-5.50). In a multivariate analysis, edema (OR 3.11, 95% CI 1.46-6.65, p = 0.003) and atypical histology (OR 2.00, 95% CI 1.03-3.90, p = 0.041) were positive predictors of preoperative seizures, while genomic subgroup was not, such that the effect of an NF2 mutation was indirectly mediated through atypical histology and edema (p = 0.012). Seizure freedom was achieved in 83.3% of the cohort, and only 20.8% of the seizure-free patients, who were more likely to have undergone gross-total resection (p = 0.031), were able to discontinue antiepileptic drug use postoperatively. Preoperative seizures (OR 3.54, 95% CI 1.37-9.12, p = 0.009), recurrent tumors (OR 2.89, 95% CI 1.08-7.74, p = 0.035), and tumors requiring postoperative radiation (OR 2.82, 95% CI 1.09-7.33, p = 0.033) were significant predictors of postoperative seizures in a multivariate analysis.

CONCLUSIONS

Seizures are relatively common at meningioma presentation. While NF2-mutated tumors are significantly associated with preoperative seizures, the association appears to be mediated through edema and atypical histology. Patients who undergo radiation and/or have a recurrence are at risk for postoperative seizures, regardless of the extent of resection. Preoperative seizures may indeed portend a more potentially aggressive molecular entity and challenging clinical course with a higher risk of recurrence.

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.

Construction and Validation of a 13-Gene Signature for Prognosis Prediction in Medulloblastoma

Background: Recent studies have identified several molecular subgroups of medulloblastoma associated with distinct clinical outcomes; however, no robust gene signature has been established for prognosis prediction. Our objective was to construct a robust gene signature-based model to predict the prognosis of patients with medulloblastoma.

Methods: Expression data of medulloblastomas were acquired from the Gene Expression Omnibus (GSE85217, n = 763; GSE37418, n = 76). To identify genes associated with overall survival (OS), we performed univariate survival analysis and least absolute shrinkage and selection operator (LASSO) Cox regression. A risk score model was constructed based on selected genes and was validated using multiple datasets. Differentially expressed genes (DEGs) between the risk groups were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and protein–protein interaction (PPI) analyses were performed. Network modules and hub genes were identified using Cytoscape. Furthermore, tumor microenvironment (TME) was evaluated using ESTIMATE algorithm. Tumor-infiltrating immune cells (TIICs) were inferred using CIBERSORTx.

Results: A 13-gene model was constructed and validated. Patients classified as high-risk group had significantly worse OS than those as low-risk group (Training set: p < 0.0001; Validation set 1: p < 0.0001; Validation set 2: p = 0.00052). The area under the curve (AUC) of the receiver operating characteristic (ROC) analysis indicated a good performance in predicting 1-, 3-, and 5-year OS in all datasets. Multivariate analysis integrating clinical factors demonstrated that the risk score was an independent predictor for the OS (validation set 1: p = 0.001, validation set 2: p = 0.004). We then identified 265 DEGs between risk groups and PPI analysis predicted modules that were highly related to central nervous system and embryonic development. The risk score was significantly correlated with programmed death-ligand 1 (PD-L1) expression (p < 0.001), as well as immune score (p = 0.035), stromal score (p = 0.010), and tumor purity (p = 0.010) in Group 4 medulloblastomas. Correlations between the 13-gene signature and the TIICs in Sonic hedgehog and Group 4 medulloblastomas were revealed.

Conclusion: Our study constructed and validated a robust 13-gene signature model estimating the prognosis of medulloblastoma patients. We also revealed genes and pathways that may be related to the development and prognosis of medulloblastoma, which might provide candidate targets for future investigation.

Correlations between genomic subgroup and clinical features in a cohort of more than 3000 meningiomas

OBJECTIVE

Recent large-cohort sequencing studies have investigated the genomic landscape of meningiomas, identifying somatic coding alterations in NF2, SMARCB1, SMARCE1, TRAF7, KLF4, POLR2A, BAP1, and members of the PI3K and Hedgehog signaling pathways. Initial associations between clinical features and genomic subgroups have been described, including location, grade, and histology. However, further investigation using an expanded collection of samples is needed to confirm previous findings, as well as elucidate relationships not evident in smaller discovery cohorts.

METHODS

Targeted sequencing of established meningioma driver genes was performed on a multiinstitution cohort of 3016 meningiomas for classification into mutually exclusive subgroups. Relevant clinical information was collected for all available cases and correlated with genomic subgroup. Nominal variables were analyzed using Fisher's exact tests, while ordinal and continuous variables were assessed using Kruskal-Wallis and 1-way ANOVA tests, respectively. Machine-learning approaches were used to predict genomic subgroup based on noninvasive clinical features.

RESULTS

Genomic subgroups were strongly associated with tumor locations, including correlation of HH tumors with midline location, and non-NF2 tumors in anterior skull base regions. NF2 meningiomas were significantly enriched in male patients, while KLF4 and POLR2A mutations were associated with female sex. Among histologies, the results confirmed previously identified relationships, and observed enrichment of microcystic features among "mutation unknown" samples. Additionally, KLF4-mutant meningiomas were associated with larger peritumoral brain edema, while SMARCB1 cases exhibited elevated Ki-67 index. Machine-learning methods revealed that observable, noninvasive patient features were largely predictive of each tumor's underlying driver mutation.

CONCLUSIONS

Using a rigorous and comprehensive approach, this study expands previously described correlations between genomic drivers and clinical features, enhancing our understanding of meningioma pathogenesis, and laying further groundwork for the use of targeted therapies. Importantly, the authors found that noninvasive patient variables exhibited a moderate predictive value of underlying genomic subgroup, which could improve with additional training data. With continued development, this framework may enable selection of appropriate precision medications without the need for invasive sampling procedures.