Prognostic Model That Predicts Benefits of Adjuvant Radiotherapy in Patients With High Grade Meningioma

Loss of H3K27me3 expression enriches in recurrent grade 1&2 meningiomas and maintains as a biomarker stratifying progression risk

PURPOSE

To determine if loss of H3K27me3 could predict higher risk of re-recurrence in recurrent meningiomas.

METHODS

A retrospective, single-center cohort study was performed for patients who underwent resection of recurrent grade 1 (N = 132) &2 (N = 32) meningiomas from 2009 to 2013. Association of H3K27me3 staining and clinical parameters was analyzed. Additionally, H3K27me3 staining was performed from 45 patients whose tumors recurred and were resected during the follow-up, to evaluate H3K27me3 change during tumor progression. Survival analysis was performed as well.

RESULTS

Loss of H3K27me3 expression was observed in 83 patients, comprising 63 grade 1 (47.7%) and 20 grade 2 patients (62.5%). Both grade 1 (p < 0.001) and grade 2 recurrent meningiomas (p < 0.001) had a higher frequency of H3K27me3 loss, compared to de novo meningiomas. 8 of 27 tumors with retained H3K27me3 lost H3K27me3 during re-recurrence (29.6%), while no gain of H3K27me3 was observed in progressive disease from 18 tumors with H3K27me3 loss. Loss of H3K27me3 expression was associated with an earlier re-recurrence in recurrent meningiomas grade 1 and 2 (p < 0.001), and was an independent prognostic factor for PFS in recurrent grade 1 meningiomas (p = 0.005).

CONCLUSION

Compared to primary meningiomas, recurrent meningiomas more predominantly had loss of H3K27me3 expression, and further loss can occur during the progression of recurrent tumors. Our results further demonstrated that loss of H3K27me3 predicted shorter PFS in recurrent grade 1 and grade 2 meningiomas. Our work thus supports clinical testing of H3K27me3 in recurrent meningiomas WHO grade 1 and 2.

Evaluating diagnostic accuracy and determining optimal diagnostic thresholds of different approaches to [68Ga]-DOTATATE PET/MRI analysis in patients with meningioma

Multiple approaches with [⁶⁸Ga]-DOTATATE, a somatostatin analog PET radiotracer, have demonstrated clinical utility in evaluation of meningioma but have not been compared directly. Our purpose was to compare diagnostic performance of different approaches to quantitative brain [⁶⁸Ga]-DOTATATE PET/MRI analysis in patients with suspected meningioma recurrence and to establish the optimal diagnostic threshold for each method. Patients with suspected meningioma were imaged prospectively with [⁶⁸Ga]-DOTATATE brain PET/MRI. Lesions were classified as meningiomas and post-treatment change (PTC), using follow-up pathology and MRI as reference standard. Lesions were reclassified using the following methods: absolute maximum SUV threshold (SUV), SUV ratio (SUVR) to superior sagittal sinus (SSS) (SUVRsss), SUVR to the pituitary gland (SUVRpit), and SUVR to the normal brain parenchyma (SUVRnorm). Diagnostic performance of the four methods was compared using contingency tables and McNemar’s test. Previously published pre-determined thresholds were assessed where applicable. The optimal thresholds for each method were identified using Youden’s J statistics. 166 meningiomas and 41 PTC lesions were identified across 62 patients. SUV, SUVRsss, SUVRpit, and SUVRnorm of meningioma were significantly higher than those of PTC (P < 0.0001). The optimal thresholds for SUV, SUVRsss, SUVRpit, and SUVRnorm were 4.7, 3.2, 0.3, and 62.6, respectively. At the optimal thresholds, SUV had the highest specificity (97.6%) and SUVRsss had the highest sensitivity (86.1%). An ROC analysis of SUV, SUVRsss, SUVRpit, and SUVRnorm revealed AUC of 0.932, 0.910, 0.915, and 0.800, respectively (P < 0.0001). Developing a diagnostic threshold is key to wider clinical translation of [⁶⁸Ga]-DOTATATE PET/MRI in meningioma evaluation. We found that the SUVRsss method may have the most robust combination of sensitivity and specificity in the diagnosis of meningioma in the post-treatment setting, with the optimal threshold of 3.2. Future studies validating our findings in different patient populations are needed to continue optimizing the diagnostic performance of [⁶⁸Ga]-DOTATATE PET/MRI in meningioma patients.

Trial registration: ClinicalTrials.gov Identifier: NCT04081701. Registered 9 September 2019. https://clinicaltrials.gov/ct2/show/NCT04081701.

Biology and Treatment of Meningiomas: A Reappraisal

Meningiomas are largely indolent tumors with a benign clinical course, but a minority exhibit aggressive behavior characterized by rapid growth, neurologic deficits, and increased mortality. Identifying high-risk patients requiring intervention is challenging, but recent insights into meningioma biology provide a useful guide for decision making. Standard of care for recurrent or biologically aggressive tumors consists of surgery and radiation therapy. Systemic therapies targeting vascular endothelial growth factor signaling and somatostatin analogues are potential options for those with refractory disease but display only modest activity. New paradigms in meningioma clinical trial design provide hope for improved options in the future.

TERT Alterations Predict Tumor Progression in De Novo High-Grade Meningiomas Following Adjuvant Radiotherapy

Background

Adjuvant radiotherapy (RT) is one of the most commonly used treatments for de novo high-grade meningiomas (HGMs) after surgery, but genetic determinants of clinical benefit are poorly characterized.

Objective

We describe efforts to integrate clinical genomics to discover predictive biomarkers that would inform adjuvant treatment decisions in de novo HGMs.

Methods

We undertook a retrospective analysis of 37 patients with de novo HGMs following RT. Clinical hybrid capture-based sequencing assay covering 184 genes was performed in all cases. Associations between tumor clinical/genomic characteristics and RT response were assessed. Overall survival (OS) and progression-free survival (PFS) curves were plotted using the Kaplan–Meier method.

Results

Among the 172 HGMs from a single institution, 42 cases (37 WHO grade 2 meningiomas and five WHO grade 3 meningiomas) were identified as de novo HGMs following RT. Only TERT mutations [62.5% C228T; 25% C250T; 12.5% copy number amplification (CN amp.)] were significantly associated with tumor progression after postoperative RT (adjusted p = 0.003). Potential different somatic interactions between TERT and other tested genes were not identified. Furthermore, TERT alterations (TERT-alt) were the predictor of tumor progression (Fisher’s exact tests, p = 0.003) and were associated with decreased PFS (log-rank test, p = 0.0114) in de novo HGMs after RT.

Conclusion

Our findings suggest that TERT-alt is associated with tumor progression and poor outcome of newly diagnosed HGM patients after postoperative RT.

Establishment and Validation of an Integrated Model to Predict Postoperative Recurrence in Patients With Atypical Meningioma

Background

This study aims to establish an integrated model based on clinical, laboratory, radiological, and pathological factors to predict the postoperative recurrence of atypical meningioma (AM).

Materials and Methods

A retrospective study of 183 patients with AM was conducted. Patients were randomly divided into a training cohort (n = 128) and an external validation cohort (n = 55). Univariable and multivariable Cox regression analyses, the least absolute shrinkage and selection operator (LASSO) regression analysis, time-dependent receiver operating characteristic (ROC) curve analysis, and evaluation of clinical usage were used to select variables for the final nomogram model.

Results

After multivariable Cox analysis, serum fibrinogen >2.95 g/L (hazard ratio (HR), 2.43; 95% confidence interval (CI), 1.05–5.63; p = 0.039), tumor located in skull base (HR, 6.59; 95% CI, 2.46-17.68; p < 0.001), Simpson grades III–IV (HR, 2.73; 95% CI, 1.01–7.34; p = 0.047), tumor diameter >4.91 cm (HR, 7.10; 95% CI, 2.52–19.95; p < 0.001), and mitotic level ≥4/high power field (HR, 2.80; 95% CI, 1.16–6.74; p = 0.021) were independently associated with AM recurrence. Mitotic level was excluded after LASSO analysis, and it did not improve the predictive performance and clinical usage of the model. Therefore, the other four factors were integrated into the nomogram model, which showed good discrimination abilities in training cohort (C-index, 0.822; 95% CI, 0.759–0.885) and validation cohort (C-index, 0.817; 95% CI, 0.716–0.918) and good match between the predicted and observed probability of recurrence-free survival.

Conclusion

Our study established an integrated model to predict the postoperative recurrence of AM.

MEF2C silencing downregulates NF2 and E-cadherin and enhances Erastin-induced ferroptosis in meningioma

BACKGROUND

Ferroptosis, a programmed cell death characterized by lipid peroxidation, is implicated in various diseases including cancer. Although cell density-dependent E-cadherin and Merlin/Neurofibromin (NF2) loss can modulate ferroptosis, the role of ferroptosis and its potential link to NF2 status and E-cadherin expression in meningioma remain unknown.

METHODS

Relationship between ferroptosis modulators expression and NF2 mutational status was examined in 35 meningiomas (10 NF2 loss and 25 NF2 wildtype). The impact of NF2 and E-cadherin on ferroptosis were examined by LDH release, lipid peroxidation and western blot assays in IOMM-Lee, CH157 and patient-derived meningioma cell models. Luciferase reporter and chromatin immunoprecipitation assays were used to assess the ability of MEF2C (myocyte enhancer factor 2C) to drive expression of NF2 and CDH1 (E-cadherin). Therapeutic efficacy of Erastin-induced ferroptosis was tested in xenograft mouse models.

RESULTS

Meningioma cells with NF2 inactivation were susceptible to Erastin-induced ferroptosis. Meningioma cells grown at higher density increased expression of E-Cadherin, which suppressed Erastin-induced ferroptosis. Maintaining NF2 and E-cadherin inhibited ferroptosis-related lipid peroxidation and meningioma cell death. MEF2C was found to drive the expression of both NF2 and E-cadherin. MEF2C silencing enhanced Erastin-induced ferroptotic meningioma cell death and lipid peroxidation levels in vitro, which was limited by forced expression of MEF2C targets, NF2 and E-Cadherin. In vivo, anti-meningioma effect of Erastin was augmented by MEF2C knockdown and was counteracted by NF2 or E-Cadherin.

CONCLUSIONS

NF2 loss and low E-cadherin create susceptibility to ferroptosis in meningioma. MEF2C could be a new molecular target in ferroptosis-inducing therapies for meningioma.