Multiple Meningiomas as a Criterion for the Diagnosis of Neurofibromatosis Type 2 and Other Tumor Predisposition Syndromes

Meningioma: International Consortium on Meningiomas consensus review on scientific advances and treatment paradigms for clinicians, researchers, and patients

Meningiomas are the most common primary intracranial tumors in adults and are increasing in incidence due to the aging population and increased access to neuroimaging. While most exhibit nonmalignant behavior, a subset of meningiomas are biologically aggressive and are associated with treatment resistance, resulting in significant neurologic morbidity and even mortality. In recent years, meaningful advances in our understanding of the biology of these tumors have led to the incorporation of molecular biomarkers into their grading and prognostication. However, unlike other central nervous system (CNS) tumors, a unified molecular taxonomy for meningiomas has not yet been established and remains an overarching goal of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official World Health Organization (cIMPACT-NOW) working group. Additionally, clinical equipoise still remains on how specific meningioma cases and patient populations should be optimally managed. To address these existing gaps, members of the International Consortium on Meningiomas including field-leading experts, have prepared this comprehensive consensus narrative review directed toward clinicians, researchers, and patients. Included in this manuscript are detailed overviews of proposed molecular classifications, novel biomarkers, contemporary treatment strategies, trials on systemic therapies, health-related quality-of-life studies, and management strategies for unique meningioma patient populations. In each section, we discuss the current state of knowledge as well as ongoing clinical and research challenges to road map future directions for further investigation.

Update on Cancer Predisposition Syndromes and Surveillance Guidelines for Childhood Brain Tumors

Tumors of the central nervous system (CNS) comprise the second most common group of neoplasms in childhood. The incidence of germline predisposition among children with brain tumors continues to grow as our knowledge on disease etiology increases. Some children with brain tumors may present with nonmalignant phenotypic features of specific syndromes (e.g., nevoid basal cell carcinoma syndrome, neurofibromatosis type 1 and type 2, DICER1 syndrome, and constitutional mismatch-repair deficiency), while others may present with a strong family history of cancer (e.g., Li-Fraumeni syndrome) or with a rare tumor commonly found in the context of germline predisposition (e.g., rhabdoid tumor predisposition syndrome). Approximately 50% of patients with a brain tumor may be the first in a family identified to have a predisposition. The past decade has witnessed a rapid expansion in our molecular understanding of CNS tumors. A significant proportion of CNS tumors are now well characterized and known to harbor specific genetic changes that can be found in the germline. Additional novel predisposition syndromes are also being described. Identification of these germline syndromes in individual patients has not only enabled cascade testing of family members and early tumor surveillance but also increasingly affected cancer management in those patients. Therefore, the AACR Cancer Predisposition Working Group chose to highlight these advances in CNS tumor predisposition and summarize and/or generate surveillance recommendations for established and more recently emerging pediatric brain tumor predisposition syndromes.

A Novel Multi-Model High Spatial Resolution Method for Analysis of DCE MRI Data: Insights from Vestibular Schwannoma Responses to Antiangiogenic Therapy in Type II Neurofibromatosis

This study aimed to develop and evaluate a new DCE-MRI processing technique that combines LEGATOS, a dual-temporal resolution DCE-MRI technique, with multi-kinetic models. This technique enables high spatial resolution interrogation of flow and permeability effects, which is currently challenging to achieve. Twelve patients with neurofibromatosis type II-related vestibular schwannoma (20 tumours) undergoing bevacizumab therapy were imaged at 1.5 T both before and at 90 days following treatment. Using the new technique, whole-brain, high spatial resolution images of the contrast transfer coefficient (Ktrans), vascular fraction (vp), extravascular extracellular fraction (ve), capillary plasma flow (Fp), and the capillary permeability-surface area product (PS) could be obtained, and their predictive value was examined. Of the five microvascular parameters derived using the new method, baseline PS exhibited the strongest correlation with the baseline tumour volume (p = 0.03). Baseline ve showed the strongest correlation with the change in tumour volume, particularly the percentage tumour volume change at 90 days after treatment (p < 0.001), and PS demonstrated a larger reduction at 90 days after treatment (p = 0.0001) when compared to Ktrans or Fp alone. Both the capillary permeability-surface area product (PS) and the extravascular extracellular fraction (ve) significantly differentiated the 'responder' and 'non-responder' tumour groups at 90 days (p < 0.05 and p < 0.001, respectively). These results highlight that this novel DCE-MRI analysis approach can be used to evaluate tumour microvascular changes during treatment and the need for future larger clinical studies investigating its role in predicting antiangiogenic therapy response.

Sporadic multiple intracranial meningioma does not infer worse patient outcomes: results from a case control study

BACKGROUND

Sporadic multiple meningioma are uncommon. Population-based data suggests that these patients have a reduced overall survival when compared to patients with solitary meningioma. The aim of this study was to investigate the clinical outcomes in multiple and solitary meningioma.

METHODS

A single-center matched cohort study (2008-2018) was performed. Patients with synchronous multiple meningioma at presentation, with no history of prior intracranial radiation, concurrent hormone replacement therapy or features of NF2-schwannomatosis were included. Eligible patients were matched 1:1 to patients with solitary meningioma. Outcomes of interest were occurrence of an intervention, recurrence, new meningioma development and mortality.

RESULTS

Thirty-four patients harboring 76 meningioma at presentation were included. Mean age was 59.3 years (SD = 13.5). Thirty-one (91.2%) were female. The median number of meningioma per patient was 2 (range 2-6). Eighteen patients (52.9%) were symptomatic at presentation. Median overall follow-up was 80.6 months (IQR 44.1-99.6). Compared to patients with a sporadic meningioma, there was no difference in intervention rates (67.6% vs 70.6%, P = 0.792). Eight patients (34.8%) with a multiple meningioma had a WHO grade 2 meningioma compared to 7 (29.2%) with a solitary meningioma (P = 0.679). Median recurrence-free survival was 89 months (95% CI 76-104) with no difference between the two groups (P = 0.209). Mean overall survival was 132 months (95% CI 127-138) with no difference between the two groups (P = 0.860). One patient with multiple meningioma developed two further new meningioma 36 months following diagnosis.

CONCLUSION

Sporadic multiple meningioma may not have worse clinical outcomes. Management of patients with sporadic multiple meningioma should be tailored towards the symptomatic meningioma or high-risk asymptomatic meningioma.