Clinical Significance of Molecular Alterations and Systemic Therapy for Meningiomas: Where Do We Stand?

A novel patient-derived meningioma spheroid model as a tool to study and treat epithelial-to-mesenchymal transition (EMT) in meningiomas

Meningiomas are the most common intracranial brain tumours. These tumours are heterogeneous and encompass a wide spectrum of clinical aggressivity. Treatment options are limited to surgery and radiotherapy and have a risk of post-operative morbidities and radiation neurotoxicity, reflecting the need for new therapies. Three-dimensional (3D) patient-derived cell culture models have been shown to closely recapitulate in vivo tumour biology, including microenvironmental interactions and have emerged as a robust tool for drug development. Here, we established a novel easy-to-use 3D patient-derived meningioma spheroid model using a scaffold-free approach. Patient-derived meningioma spheroids were characterised and compared to patient tissues and traditional monolayer cultures by histology, genomics, and transcriptomics studies. Patient-derived meningioma spheroids closely recapitulated morphological and molecular features of matched patient tissues, including patient histology, genomic alterations, and components of the immune microenvironment, such as a CD68 + and CD163 + positive macrophage cell population. Comprehensive transcriptomic profiling revealed an increase in epithelial-to-mesenchymal transition (EMT) in meningioma spheroids compared to traditional monolayer cultures, confirming this model as a tool to elucidate EMT in meningioma. Therefore, as proof of concept study, we developed a treatment strategy to target EMT in meningioma. We found that combination therapy using the MER tyrosine kinase (MERTK) inhibitor UNC2025 and the histone deacetylase (HDAC) inhibitor Trichostatin A (TSA) effectively decreased meningioma spheroid viability and proliferation. Furthermore, we demonstrated this combination therapy significantly increased the expression of the epithelial marker E-cadherin and had a repressive effect on WHO grade 2-derived spheroid invasion, which is suggestive of a partial reversal of EMT in meningioma spheroids.

Interdisciplinary Therapeutic Approaches to Atypical and Malignant Meningiomas

Meningiomas have the highest incidence among brain tumors. In contrast to benign tumors that constitute the majority of this tumor entity, the treatment of aggressive meningiomas (WHO Grade 2 and 3) is more challenging, requiring gross total removal of the tumor and the affected dura and adjuvant radiotherapy. Sometimes the location and/or the configuration of the tumor do not favor radical surgical resection without endangering the patient's clinical condition after surgery and pharmacological therapy has, until now, not been proven to be a reliable alternative. Discussion: In this narrative review, we discuss the current literature with respect to the management of meningiomas, discussing the importance of the grade of resection in the overall prognosis of the patient and in the planning of adjuvant therapy. Conclusions: According to the location and size of the tumor, radical resection should be taken into consideration. In patients with aggressive meningiomas, adjuvant radiotherapy should be performed after surgery. In cases of skull base meningiomas, a maximal, though safe, resection should take place before adjuvant therapy. An interdisciplinary approach is beneficial for patients with primary or recurrent meningioma.

Rhabdoid meningioma with a history of Budd-Chiari syndrome: a case report and review of the literature

Background

Rhabdoid meningioma and Budd-Chiari syndrome are both extremely rare, and there is no report describing the two diseases occurring in the same patient thus far. Herein, we showed an unusual case of rhabdoid meningioma with a history of Budd-Chiari syndrome.

Case presentation

The man was found to have abnormal liver function during physical examination in 2016 at 36 and was not paid attention to it. In 2019, he went to Beijing YouAn Hospital Affiliated to Capital Medical University for the decompensation of cirrhosis and was diagnosed with Budd-Chiari syndrome, subsequent angiography of the inferior vena cava combined with balloon dilatation were performed, the anticoagulation and hepatoprotective therapy were performed for a long time. When he turned 40 who had magnetic resonance imaging (MRI) that showed a left frontotemporal lobe space-occupying lesion, and postoperative pathological examination confirmed rhabdoid meningioma. He underwent surgery and postoperative adjuvant radiotherapy, but then he developed severe psychiatric symptoms and eventually succumbed to a lung infection two months after treatment.

Conclusions

Budd-Chiari syndrome and Rhabdoid meningiomas are both extremely rare diseases. To the best of our knowledge, there is no report that the two rare diseases occurred in the same patient, and this is the first case. However, whether there is any link between the two diseases is unclear, more researches are needed to confirm it in the future.

Meningiomas with CNS invasion

CNS invasion has been included as an independent criterion for the diagnosis of a high-grade (WHO and CNS grade 2 and 3) meningioma in the 2016 and more recently in the 2021 WHO classification. However, the prognostic role of brain invasion has recently been questioned. Also, surgical treatment for brain invasive meningiomas may pose specific challenges. We conducted a systematic review of the 2016-2022 literature on brain invasive meningiomas in Pubmed, Scopus, Web of Science and the Cochrane Library. The prognostic relevance of brain invasion as a stand-alone criterion is still unclear. Additional and larger studies using robust definitions of histological brain invasion and addressing the issue of sampling errors are clearly warranted. Although the necessity of molecular profiling in meningioma grading, prognostication and decision making in the future is obvious, specific markers for brain invasion are lacking for the time being. Advanced neuroimaging may predict CNS invasion preoperatively. The extent of resection (e.g., the Simpson grading) is an important predictor of tumor recurrence especially in higher grade meningiomas, but also - although likely to a lesser degree - in benign tumors, and therefore also in brain invasive meningiomas with and without other histological features of atypia or malignancy. Hence, surgery for brain invasive meningiomas should follow the principles of maximal but safe resections. There are some data to suggest that safety and functional outcomes in such cases may benefit from the armamentarium of surgical adjuncts commonly used for surgery of eloquent gliomas such as intraoperative monitoring, awake craniotomy, DTI tractography and further advanced intraoperative brain tumor visualization.

Paths of Evolution of Progressive Anaplastic Meningiomas: A Clinical and Molecular Pathology Study

Grade 3 meningiomas are rare malignant tumors that can originate de novo or from the progression of lower grade meningiomas. The molecular bases of anaplasia and progression are poorly known. We aimed to report an institutional series of grade 3 anaplastic meningiomas and to investigate the evolution of molecular profile in progressive cases. Clinical data and pathologic samples were retrospectively collected. VEGF, EGFR, EGFRvIII, PD-L1; and Sox2 expression; MGMT methylation status; and TERT promoter mutation were assessed in paired meningioma samples collected from the same patient before and after progression using immunohistochemistry and PCR. Young age, de novo cases, origin from grade 2 in progressive cases, good clinical status, and unilateral side, were associated with more favorable outcomes. In ten progressive meningiomas, by comparing molecular profile before and after progression, we identified two subgroups of patients, one defined by Sox2 increase, suggesting a stem-like, mesenchymal phenotype, and another defined by EGFRvIII gain, suggesting a committed progenitor, epithelial phenotype. Interestingly, cases with Sox2 increase had a significantly shortened survival compared to those with EGFRvIII gain. PD-L1 increase at progression was also associated with worse prognosis, portending immune escape. We thus identified the key drivers of meningioma progression, which can be exploited for personalized treatments.

Different Approaches to Study Molecular Blueprint and Biological Behavior of Brain Tumors: Editorial to the Special Issue "Advances in Molecular Genetics of Brain Tumors"

Cancer remains one of the leading causes of mortality worldwide [...].

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.

Clinical Management of Supratentorial Non-Skull Base Meningiomas

Supratentorial non-skull base meningiomas are the most common primary central nervous system tumor subtype. An understanding of their pathophysiology, imaging characteristics, and clinical management options will prove of substantial value to the multi-disciplinary team which may be involved in their care. Extensive review of the broad literature on the topic is conducted. Narrowing the scope to meningiomas located in the supratentorial non-skull base anatomic location highlights nuances specific to this tumor subtype. Advances in our understanding of the natural history of the disease and how findings from both molecular pathology and neuroimaging have impacted our understanding are discussed. Clinical management and the rationale underlying specific approaches including observation, surgery, radiation, and investigational systemic therapies is covered in detail. Future directions for probable advances in the near and intermediate term are reviewed.