Regression of a meningioma during paclitaxel and bevacizumab therapy for breast cancer

Medical Management of Meningiomas

Meningiomas represent the most common type of benign tumor of the extra-axial compartment. Although most meningiomas are benign World Health Organization (WHO) grade 1 lesions, the increasingly prevalent of WHO grade 2 lesion and occasional grade 3 lesions show worsened recurrence rates and morbidity. Multiple medical treatments have been evaluated but show limited efficacy. We review the status of medical management in meningiomas, highlighting successes and failures of various treatment options. We also explore newer studies evaluating the use of immunotherapy in management.

Docetaxel targets aggressive methylation profiles and serves as a radiosensitizer in high-risk meningiomas

BACKGROUND

Meningioma is the most common primary intracranial tumor in adults. A subset of these tumors recur and invade the brain, even after surgery and radiation, resulting in significant disability. There is currently no standard-of-care chemotherapy for meningiomas. As genomic DNA methylation profiling can prognostically stratify these lesions, we sought to determine whether any existing chemotherapies might be effective against meningiomas with high-risk methylation profiles.

METHODS

A previously published dataset of meningioma methylation profiles was used to screen for clinically significant CpG methylation events and associated cellular pathways. Based on these results, patient-derived meningioma cell lines were used to test candidate drugs in vitro and in vivo, including efficacy in conjunction with radiotherapy.

RESULTS

We identified 981 genes for which methylation of mapped CpG sites was related to progression-free survival in meningiomas. Associated molecular pathways were cross-referenced with FDA-approved cancer drugs, which nominated Docetaxel as a promising candidate for further preclinical analyses. Docetaxel arrested growth in 17 meningioma cell sources, representing all tumor grades, with a clinically favorable IC50 values ranging from 0.3 nM to 10.7 mM. The inhibitory effects of this medication scaled with tumor doubling time, with maximal benefit in fast-growing lesions. The combination of Docetaxel and radiation therapy increased markers of apoptosis and double-stranded DNA breaks, and extended the survival of mice engrafted with meningioma cells relative to either modality alone.

CONCLUSIONS

Global patterns of DNA methylation may be informative for the selection of chemotherapies against meningiomas, and existing drugs may enhance radiation sensitivity in high-risk cases.

The role of bevacizumab for treatment-refractory intracranial meningiomas: a single institution's experience and a systematic review of the literature

INTRODUCTION

Meningiomas account for over 30% of all primary brain tumors. While surgery can be curative for these tumors, several factors may lead to a higher likelihood of recurrence. For recurrent meningiomas, bevacizumab may be considered as a therapeutic agent, but literature regarding its efficacy is sparse. Thus, we present a systematic review of the literature and case series of patients from our institution with treatment-refractory meningiomas who received bevacizumab.

METHODS

Patients at our institution who were diagnosed with recurrent meningioma between January 2000 and September 2020 and received bevacizumab monotherapy were included in this study. Bevacizumab duration and dosages were noted, as well as progression-free survival (PFS) after the first bevacizumab injection. A systematic review of the literature was also performed.

RESULTS

Twenty-three patients at our institution with a median age of 55 years at initial diagnosis qualified for this study. When bevacizumab was administered, 2 patients had WHO grade I meningiomas, 10 patients had WHO grade II meningiomas, and 11 patients had WHO grade III meningiomas. Median PFS after the first bevacizumab injection was 7 months. Progression-free survival rate at 6 months was 57%. Two patients stopped bevacizumab due to hypertension and aphasia. Systematic review of the literature showed limited ability for bevacizumab to control tumor growth.

CONCLUSION

Bevacizumab is administered to patients with treatment-refractory meningiomas and, though its effectiveness is limited, outperforms other systemic therapies reported in the literature. Further studies are required to identify a successful patient profile for utilization of bevacizumab.

Everolimus and Octreotide for Patients with Recurrent Meningioma: Results from the Phase II CEVOREM Trial

PURPOSE

Aggressive meningiomas that progress after surgery/radiotherapy represent an unmet medical need. Strong and constant expression of SSTR2A receptors and activation of the Pi3K/Akt/mTOR pathway have been demonstrated in meningiomas. The combination of everolimus, an mTOR inhibitor, and octreotide, a somatostatin agonist, has shown additive antitumor effect in vitro. The phase II CEVOREM trial investigated the efficacy of this combination on recurrent meningiomas.

PATIENTS AND METHODS

Patients with documented recurrent tumor progression ineligible for further surgery/radiotherapy were eligible to receive octreotide (30 mg/d, day 1) and everolimus (10 mg/d, days 1-28). The primary endpoint was the 6-month progression-free survival rate (PFS6). The secondary endpoints were overall survival, response rate, tumor growth rate according to central review, and safety.

RESULTS

A total of 20 patients were enrolled, including 2 with World Health Organization (WHO) grade I tumors, 10 with WHO grade II tumors, and 8 with WHO grade III tumors; furthermore, 4 patients harbored NF2 germline mutation. The overall PFS6 was 55% [95% confidence interval (CI), 31.3%-73.5%], and overall 6- and 12-month survival rates were 90% (95% CI, 65.6%-97.4%) and 75% (95% CI, 50.0%-88.7%), respectively. A major decrease (>50%) was observed in the growth rate at 3 months in 78% of tumors. The median tumor growth rate decreased from 16.6%/3 months before inclusion to 0.02%/3 months at 3 months (P < 0.0002) and 0.48%/3 months at 6 months after treatment (P < 0.0003).

CONCLUSIONS

The combination of everolimus and octreotide was associated with clinical and radiological activity in aggressive meningiomas and warrants further studies. Decrease in the tumor volume growth rate should be considered a complementary and sensitive endpoint to select potentially effective drugs for recurrent meningiomas.

Vascularity of meningiomas

Information on the vascular supply to meningiomas is critical to the neurosurgeon. Most meningiomas are supplied by the external carotid artery, though many get pial contribution as well. Angiogenesis is critical for these neoplasms to grow. Vascular endothelial growth factor (VEGF) has been a popular target of research to decrease angiogenesis. Peritumoral brain edema (PTBE) is occasionally seen in meningiomas, which makes surgical resection more challenging. The exact cause of PTBE remains unclear, but a number of factors have been postulated to contribute. Assessment of the vascularity of meningiomas is best carried out with angiography, but noninvasive techniques are improving, diminishing the need for more invasive imaging. Embolization of tumors can be performed to minimize perioperative blood loss and potentially lower surgical morbidity. However, it has not been shown to improve outcomes, and procedural risks exist. Higher grade tumors commonly have higher vascularity. Higher vascular meningiomas are more likely to recur and have higher levels of VEGF. The vascularity of meningiomas remains a topic of interest and is the focus of many research projects.

Emerging Medical Treatments for Meningioma in the Molecular Era

Meningiomas are the most common type of primary central nervous system tumors. Approximately, 80% of meningiomas are classified by the World Health Organization (WHO) as grade I, and 20% of these tumors are grade II and III, considered high-grade meningiomas (HGMs). Clinical control of HGMs, as well as meningiomas that relapse after surgery, and radiation therapy is difficult, and novel therapeutic approaches are necessary. However, traditional chemotherapies, interferons, hormonal therapies, and other targeted therapies have so far failed to provide clinical benefit. During the last several years, next generation sequencing has dissected the genetic heterogeneity of meningioma and enriched our knowledge about distinct oncogenic pathways driving different subtypes of meningiomas, opening up a door to new personalized targeted therapies. Molecular classification of meningioma allows a new design of clinical trials that assign patients to corresponding targeted agents based on the tumor genetic subtypes. In this review, we will shed light on emerging medical treatments of meningiomas with a particular focus on the new targets identified with genomic sequencing that have led to clinical trials testing novel compounds. Moreover, we present recent development of patient-derived preclinical models that provide platforms for assessing targeted therapies as well as strategies with novel mechanism of action such as oncolytic viruses.

Role of bevacizumab for treatment-refractory meningiomas: A systematic analysis and literature review

Background

Meningiomas are the most prevalent primary tumor of the central nervous system (CNS), and although the majority of these neoplasms are classified as benign, nearly one fourth of the lesions display an aggressive profile characterized by pleomorphic histology, high recurrence rates, and overall resistance to standard treatment. Despite the ubiquitous nature of these tumors, no adjuvant therapeutic regimen has been identified which effectively controls disease recurrence and progression after surgery and radiation, leading to a dismal prognosis in this patient population. The primary focus of this research study is, hence, to assess the recently emerging use of bevacizumab, an anti-angiogenic agent, in the treatment of meningiomas. This systematic literature review analyzes the efficacy and safety of therapeutic bevacizumab for treatment-refractory meningiomas.

Methods

A systematic PubMed search was conducted according to PRISMA guidelines to identify all relevant reports investigating the anti-angiogenic agent bevacizumab in the treatment of intracranial meningiomas. The reported parameters from pertinent retrospective reviews, prospective studies, and case studies were volumetric reduction, radiographic response, clinical stability, overall survival (OS), and progression free survival (PFS) measured at 6 and 12 months postinitiation of treatment. Complications were cataloged based on the range and severity of the therapy-related toxicities.

Results

A total of 11 articles, 5 retrospective series, 2 prospective trials, and 4 case reports, reporting on a total of 92 patients, were included in this review. The use of bevacizumab therapy for intracranial meningiomas demonstrated median overall PFS of 16.8 months (range: 6.5-22 months) and PFS-6 of 73% (range: 44%-93%).

Conclusions

Therapeutic bevacizumab, either alone or with combination chemotherapies, for select patient populations with recurrent or progressive meningiomas, offers a treatment option that confers improved overall progression-free survival. To assess OS parameters, larger randomized controlled trials assessing the use of anti-angiogenic agents for recurrent/progressive meningiomas are warranted.

Isolated Extracranial Intraosseous Metastasis of an Intracranial Meningioma following Bevacizumab Therapy: Case Report and Review of the Literature

Meningiomas account for a significant proportion of all primary intracranial tumors; distant metastasis is quite rare. We report a patient with resected, atypical meningioma. The patient's clinical course over 5 years included two craniotomies, a course of radiation, and a shortened course of bevacizumab. Only 5 months after starting bevacizumab, the patient developed an isolated left clavicular pathological fracture attributable to metastatic anaplastic meningioma. This constitutes the first report of meningioma with isolated extracranial intraosseous metastasis in the modern English literature and highlights concerns associated with the use of anti-angiogenic agents in promoting more invasive tumor phenotypes upon disease recurrence.

ERRα mediates metabolic adaptations driving lapatinib resistance in breast cancer

Despite the initial benefits of treating HER2-amplified breast cancer patients with the tyrosine kinase inhibitor lapatinib, resistance inevitably develops. Here we report that lapatinib induces the degradation of the nuclear receptor ERRα, a master regulator of cellular metabolism, and that the expression of ERRα is restored in lapatinib-resistant breast cancer cells through reactivation of mTOR signalling. Re-expression of ERRα in resistant cells triggers metabolic adaptations favouring mitochondrial energy metabolism through increased glutamine metabolism, as well as ROS detoxification required for cell survival under therapeutic stress conditions. An ERRα inverse agonist counteracts these metabolic adaptations and overcomes lapatinib resistance in a HER2-induced mammary tumour mouse model. This work reveals a molecular mechanism by which ERRα-induced metabolic reprogramming promotes survival of lapatinib-resistant cancer cells and demonstrates the potential of ERRα inhibition as an effective adjuvant therapy in poor outcome HER2-positive breast cancer.

Medical Management of Meningiomas: Current Status, Failed Treatments, and Promising Horizons

Meningiomas are benign tumors of the central nervous system, with low recurrence risk for World Health Organization (WHO) grade I lesions but a high risk for WHO grade II and III lesions. Current standard treatments include maximum safe surgical resection when indicated and radiation. Only three systemic therapies alpha-interferon, somatostatin receptor agonists, and vascular endothelial growth factor inhibitors are currently recommended by the National Comprehensive Cancer Network for treatment of recurrent meningioma. This paper aims to review medical approaches in the treatment of meningiomas.

Peritumoral brain edema in intracranial meningiomas: the emergence of vascular endothelial growth factor-directed therapy

Meningioma is the second most common type of adult intracranial neoplasm. A substantial subset of patients present with peritumoral brain edema (PTBE), which can cause significant morbidity via mass effect, complicate surgical management, and impact the safety of stereotactic radiosurgery. Recent studies suggest a close relationship between vascular endothelial growth factor-A (VEGF-A) expression and PTBE development in meningiomas. The authors performed a systematic review of the literature on the pathogenesis of PTBE in meningiomas, the effectiveness of steroid therapy, the role played by VEGF-A, and the current clinical evidence for antiangiogenic therapy to treat peritumoral brain edema. Mounting evidence suggests VEGF-A is secreted directly by meningioma cells to induce angiogenesis and edemagenesis of tumoral as well as peritumoral brain tissue. The VEGF-A cascade results in recruitment of cerebral-pial vessels and disruption of the tumor-brain barrier, which appear to be requisite for VEGF-A to have an edemagenic effect. Results of preliminary clinical studies suggest VEGF-directed therapy has modest activity against recurrent and progressive meningioma growth but can alleviate PTBE in some patients. A comprehensive understanding of the VEGF-A pathway and its modulators may hold the key to an effective therapeutic approach to treating PTBE associated with meningiomas. Further clinical trials with larger patient cohorts and longer follow-up periods are warranted to confirm the efficacy of VEGF-directed therapy.

Historical benchmarks for medical therapy trials in surgery- and radiation-refractory meningioma: a RANO review

BACKGROUND

The outcomes of patients with surgery- and radiation-refractory meningiomas treated with medical therapies are poorly defined. Published reports are limited by small patient numbers, selection bias, inclusion of mixed histologic grades and stages of illness, and World Health Organization (WHO) criteria changes. This analysis seeks to define outcome benchmarks for future clinical trial design.

METHODS

A PubMed literature search was performed for all English language publications on medical therapy for meningioma. Reports were tabulated and analyzed for number of patients, histologic grade, prior therapy, overall survival, progression-free survival (PFS), and radiographic response.

RESULTS

Forty-seven publications were identified and divided by histology and prior therapies, including only those that treated patients who were surgery and radiation refractory for further analysis. This included a variety of agents (hydroxyurea, temozolomide, irinotecan, interferon-α, mifepristone, octreotide analogues, megestrol acetate, bevacizumab, imatinib, erlotinib, and gefitinib) from retrospective, pilot, and phase II studies, exploratory arms of other studies, and a single phase III study. The only outcome extractable from all studies was the PFS 6-month rate, and a weighted average was calculated separately for WHO grade I meningioma and combined WHO grade II/III meningioma. For WHO I meningioma, the weighted average PFS-6 was 29% (95% confidence interval [CI]: 20.3%-37.7%). For WHO II/III meningioma, the weighted average PFS-6 was 26% (95% CI: 19.3%-32.7%).

CONCLUSIONS

This comprehensive review confirms the poor outcomes of medical therapy for surgery- and radiation-refractory meningioma. We recommend the above PFS-6 benchmarks for future trial design.

Emerging association between androgen deprivation therapy and male meningioma: significant expression of luteinizing hormone-releasing hormone receptor in male meningioma

BACKGROUND

There is emerging data suggesting a potential risk for meningioma growth stimulation in patients on luteinizing hormone-releasing hormone (LHRH) analogs for prostate cancer. We examined the expression of LHRH receptor (LHRH-R), progesterone receptor (PR) and Ki67 labeling index (LI) in specimens from male meningioma (MM) and female meningioma (FM) patients.

METHODS

A total of 24 MM and 24 FM paraffin blocks were retrieved from our institution between 1991 and 2008. Sections from the paraffin blocks were stained with mouse monoclonal antibodies against LHRH-R, PR and Ki67. All male patients had no previous history of prostate cancer (PCa) or previous history of hormone therapy.

RESULTS

LHRH-R positivity was extensive in 92% of MM and 88% of FM samples, with both showing strong intensity (67% and 79%, respectively). PR was positive in 20 of 24 (83%) MM and 23 of 24 (96%) FM samples. MM is less likely to exhibit Ki67 LI >4% compared with FM.

CONCLUSIONS

The majority of MM and FM samples were strongly positive for LHRH-R expression and PR expression. The emerging association of androgen deprivation therapy and meningioma growth should be recognized in urological practice. Caution should be taken when considering LHRH agonist administration for patients with PCa and concurrent meningioma or previous history of meningioma.

Drug review: Safety and efficacy of bevacizumab for glioblastoma and other brain tumors

Glioblastoma is a highly vascular tumor that expresses vascular endothelial growth factor, a key regulator of angiogenesis and tumor blood vessel permeability. Bevacizumab is a monoclonal antibody that inhibits vascular endothelial growth factor and the growth of gliomas. Bevacizumab monotherapy has proven effective for recurrent glioblastoma, and it extended progression-free survival and improved patient quality of life in various clinical trials. Some patients who receive bevacizumab experience improvements in neurological symptoms and steroid dose reductions. Bevacizumab induces a dramatic and rapid radiological response, but non-enhancing lesions are often detected on magnetic resonance imaging without enhancing lesions. Rebound phenomena such as rapid tumor regrowth are occasionally observed after the discontinuation of bevacizumab therapy. Therefore, Response Assessment in Neuro-Oncology criteria were recently devised to evaluate the efficacy and radiological response of bevacizumab treatment. Hypertension and proteinuria are characteristic adverse events associated with bevacizumab therapy. In addition, many fatal adverse events such as intracranial hemorrhage and venous thromboembolism are reported in patients treated with bevacizumab. However, these events are also associated with glioma itself, and careful attention needs to be paid to these events. Bevacizumab is used to treat various diseases including radiation necrosis and recurrent brain tumors such as brain metastases, schwannoma and meningioma, but additional clinical trials are necessary. The efficacy and current problems associated with bevacizumab in the treatment of glioblastoma and other brain tumors are reviewed.