The Clinical Outcome of Hydroxyurea Chemotherapy after Incomplete Resection of Atypical Meningiomas

The Impact of Molecular and Genetic Analysis on the Treatment of Patients with Atypical Meningiomas

Meningiomas represent approximately 40% of all primary tumors of the central nervous system (CNS) and, based on the latest World Health Organization (WHO) guidelines, are classified into three grades and fifteen subtypes. The optimal treatment comprises gross total tumor resection. The WHO grade and the extent of tumor resection assessed by the Simpson grading system are the most important predictors of recurrence. Atypical meningiomas, a grade 2 meningioma, which represent almost a fifth of all meningiomas, have a recurrence rate of around 50%. Currently, different histopathologic, cytogenetic, and molecular genetic alterations have been associated with different meningioma phenotypes; however, the data are insufficient to enable the development of specific treatment plans. The optimal treatment, in terms of adjuvant radiotherapy and postoperative systemic therapy in atypical meningiomas, remains controversial, with inconclusive evidence in the literature and existing studies. We review the recent literature to identify studies investigating relevant atypical meningioma biomarkers and their clinical application and effects on treatment options.

Hydration of N-Hydroxyurea from Ab Initio Molecular Dynamics Simulations

N-Hydroxyurea (HU) is an important chemotherapeutic agent used as a first-line treatment in conditions such as sickle cell disease and β-thalassemia, among others. To date, its properties as a hydrated molecule in the blood plasma or cytoplasm are dramatically understudied, although they may be crucial to the binding of HU to the radical catalytic site of ribonucleotide reductase, its molecular target. The purpose of this work is the comprehensive exploration of HU hydration. The topic is studied using ab initio molecular dynamic (AIMD) simulations that apply a first principles representation of the electron density of the system. This allows for the calculation of infrared spectra, which may be decomposed spatially to better capture the spectral signatures of solute-solvent interactions. The studied molecule is found to be strongly hydrated and tightly bound to the first shell water molecules. The analysis of the distance-dependent spectra of HU shows that the E and Z conformers spectrally affect, on average, 3.4 and 2.5 of the closest H2O molecules, respectively, in spheres of radii of 3.7 Å and 3.5 Å, respectively. The distance-dependent spectra corresponding to these cutoff radii show increased absorbance in the red-shifted part of the water OH stretching vibration band, indicating local enhancement of the solvent's hydrogen bond network. The radially resolved IR spectra also demonstrate that HU effortlessly incorporates into the hydrogen bond network of water and has an enhancing effect on this network. Metadynamics simulations based on AIMD methodology provide a picture of the conformational equilibria of HU in solution. Contrary to previous investigations of an isolated HU molecule in the gas phase, the Z conformer of HU is found here to be more stable by 17.4 kJ·mol-1 than the E conformer, pointing at the crucial role that hydration plays in determining the conformational stability of solutes. The potential energy surface for the OH group rotation in HU indicates that there is no intramolecular hydrogen bond in Z-HU in water, in stark contrast to the isolated solute in the gas phase. Instead, the preferred orientation of the hydroxyl group is perpendicular to the molecular plane of the solute. In view of the known chaotropic effect of urea and its N-alkyl-substituted derivatives, N-hydroxyurea emerges as a unique urea derivative that exhibits a kosmotropic ordering of nearby water. This property may be of crucial importance for its binding to the catalytic site of ribonucleotide reductase with a concomitant displacement of a water molecule.

Novel Advances in Treatment of Meningiomas: Prognostic and Therapeutic Implications

Meningiomas are the most frequent histotypes of tumors of the central nervous system. Their incidence is approximately 35% of all primary brain tumors. Although they have the status of benign lesions, meningiomas are often associated with a decreased quality of life due to focal neurological deficits that may be related. The optimal treatment is total resection. Histological grading is the most important prognostic factor. Recently, molecular alterations have been identified that are specifically related to particular phenotypes and, probably, are also responsible for grading, site, and prognostic trend. Meningiomas recur in 10-25% of cases. In these cases, and in patients with atypical or anaplastic meningiomas, the methods of approach are relatively insufficient. To date, data on the molecular biology, genetics, and epigenetics of meningiomas are insufficient. To achieve an optimal treatment strategy, it is necessary to identify the mechanisms that regulate tumor formation and progression. Combination therapies affecting multiple molecular targets are currently opening up and have significant promise as adjuvant therapeutic options. We review the most recent literature to identify studies investigating recent therapeutic treatments recently used for meningiomas.

Novel Medical Therapies in Meningiomas

Meningiomas are the most common primary brain tumor in adults and have been historically managed with surgery and radiation therapy. However, in patients with inoperable, recurrent or high-grade tumors, medical therapy is often needed. Traditional chemotherapy and hormone therapy have been largely ineffective. However, with improved understanding of the molecular drivers in meningioma, there has been increasing interest in targeted molecular and immune therapies. In this chapter, we will discuss recent advances in meningioma genetics and biology and review current clinical trials with targeted molecular treatment and other novel therapies.

Clinical presentation, diagnostic findings and outcome of dogs undergoing surgical resection for intracranial meningioma: 101 dogs

Background

Meningioma is the most common primary brain neoplasm in dogs. Further information is required regarding the expected long-term prognosis of dogs following the surgical resection of an intracranial meningioma together with the influence of adjunctive therapies. Whilst there have been several studies reporting the long-term outcome of intracranial meningioma resection following surgery alone, surgery with the use of an ultrasonic aspirator, surgery combined with radiotherapy and surgery combined with the addition of hydroxyurea, it is currently unclear which type of adjunctive therapy is associated with the most favourable outcomes. The objective of this study is to describe the presentation and outcome of dogs undergoing surgery for the resection of an intracranial meningioma and the effect of clinical factors, adjunctive therapies and meningioma histopathological subtype on the long-term outcome.

Results

A hundred and one dogs that had intracranial surgery for meningioma resection were investigated from four referral centres. 94% of dogs survived to hospital discharge with a median survival time of 386 days. Approximately 50% of dogs survived for less than a year, 25% survived between 1 and 2 years, 15% survived between 2 and 3 years and 10% survived for greater than 3 years following discharge from hospital. One or more adjunctive therapies were used in 75 dogs and the analysis of the data did not reveal a clear benefit of a specific type of adjunctive therapy. Those dogs that had a transfrontal approach had a significantly reduced survival time (MST 184 days) compared to those dogs that had a rostrotentorial approach (MST 646 days; p < 0.05). There was no association between meningioma subtype and survival time.

Conclusions

This study did not identify a clear benefit of a specific type of adjunctive therapy on the survival time. Dogs that had a transfrontal approach had a significantly reduced survival time. Intracranial surgery for meningioma resection offers an excellent prognosis for survival to discharge from hospital with a median long term survival time of 386 days.

Histopathological predictors of progression-free survival in atypical meningioma: a single-center retrospective cohort and meta-analysis

To determine the prognostic significance of histopathological features included in the diagnostic criteria of atypical meningioma for progression-free survival (PFS). We performed a retrospective cohort study and meta-analysis. Brain invasion, mitotic index, spontaneous necrosis, sheeting, prominent nucleoli, high cellularity, and small cells were the histopathological features of interest. The data from 25 studies involving 3590 patients including our cohort (n = 262) were included. The pooled HR of mitotic index at a cutoff value of 4 showed no statical significance in the gross analysis (pooled HR, 1.09; 95% CI 0.61-1.96; p = 0.7699). Furthermore, it failed to prognosticate PFS in other pooled analyses. For brain invasion, no consistent association with the progression was found in each pooled analysis according to the included studies. Among the remaining five atypical features, spontaneous necrosis, sheeting, and prominent nucleoli showed a significant correlation with PFS in the gross analysis. In the analysis that pooled the HRs from the multivariate analyses, only spontaneous necrosis had significant association with PFS. The available evidence supports that the current cutoff value of mitotic index for diagnosing atypical meningioma might be improper to have prognostic value. The prognostic significance of brain invasion also needs further evaluation.

Low-grade intracranial meningioma with bilateral pulmonary metastases incidentally detected postpartum: a case report and review of the literature

Introduction

Meningiomas are the most commonly encountered intracranial tumors, usually showing indolent behavior. Extra-axial spreading and distant metastases are seldom detected in these tumors, and lung metastasis from a low-grade meningioma is a rare event.

Case presentation

This case report aimed to present the clinical, imaging, and pathological features of a 37-year-old Caucasian pregnant woman with bilateral lung metastases incidentally detected during preoperative workup ahead of surgery for a primary intracranial meningioma. The possible metastatic routes and risk factors of dissemination to the pulmonary circulation were discussed as well.

Conclusion

Metastasis must be considered in patients with intracranial meningiomas accompanied by venous sinus invasion and extension through the calvarium. Thorough paraclinical investigations are suggested in such cases.

The PP2A subunit PR130 is a key regulator of cell development and oncogenic transformation

Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase. This enzyme is involved in a plethora of cellular processes, including apoptosis, autophagy, cell proliferation, and DNA repair. Remarkably, PP2A can act as a context-dependent tumor suppressor or promoter. Active PP2A complexes consist of structural (PP2A-A), regulatory (PP2A-B), and catalytic (PP2A-C) subunits. The regulatory subunits define the substrate specificity and the subcellular localization of the holoenzyme. Here we condense the increasing evidence that the PP2A B-type subunit PR130 is a critical regulator of cell identity and oncogenic transformation. We summarize knowledge on the biological functions of PR130 in normal and transformed cells, targets of the PP2A-PR130 complex, and how diverse extra- and intracellular stimuli control the expression and activity of PR130. We additionally review the impact of PP2A-PR130 on cardiac functions, neuronal processes, and anti-viral defense and how this might affect cancer development and therapy.

Differentially Expressed MicroRNAs in Radioresistant and Radiosensitive Atypical Meningioma: A Clinical Study in Chinese Patients

Background: For atypical meningiomas (AMs), the combination of gross total resection (GTR) and adjuvant radiotherapy (ART) is still a controversial therapeutic strategy to improve prognosis. This study analyzed the factors influencing the prognosis on AM patients treated with GTR + ART by investigating both clinical characteristics and the change in microRNA (miRNA) expression.

Materials and Methods: Adult AM patients who were admitted to the Tiantan hospital from 2008 to 2015 and underwent GTR + ART were included. Patients who suffered recurrence within 3 years after operation were considered radioresistant, while the others were considered radiosensitive. Clinical characterizations were compared between these two groups. The microRNA (miRNA) expression was detected via miRNA microarray in 10 patients, five from the radiosensitive group and from the radioresistant group.

Results: A total of 55 cases were included in this study. No significant difference was found in the clinical characteristics (gender, age, tumor location, tumor size, peritumoral brain edema, and Ki-67 index) between radiosensitive and radioresistant patients. We found seven significantly upregulated miRNAs (miR-4286, miR-4695-5p, miR-6732-5p, miR-6855-5p, miR-7977, miR-6765-3p, miR-6787-5p) and seven significantly downregulated miRNAs (miR-1275, miR-30c-1-3p, miR-4449, miR-4539, miR-4684-3p, miR-6129, miR-6891-5p) in patients resistant to radiotherapy. The differentially expressed miRNAs were enriched mostly in the fatty acid metabolic pathways (hsa00061, hsa01212) and transforming growth factor beta signaling pathway (hsa04350).

Conclusion: For AM patients treated with GTR + ART, the changes in miRNA expression discovered in this study may be a potential predictor of individual sensitivity to adjuvant radiotherapy. Further research is needed regarding the predictive power and mechanism by which these miRNAs influence prognosis.

DNA inhibitors for the treatment of brain tumors

Introduction: The worldwide incidence of central nervous system (CNS) primary tumors is increasing. Most of the chemotherapeutic agents used for treating these cancer types induce DNA damage, and their activity is affected by the functional status of repair systems involved in the detection or correction of DNA lesions. Unfortunately, treatment of malignant high-grade tumors is still an unmet medical need.Areas covered: We summarize the action mechanisms of the main DNA inhibitors used for the treatment of brain tumors. In addition, studies on new agents or drug combinations investigated for this indication are reviewed, focusing our attention on clinical trials that in the last 3 years have been completed, terminated or are still recruiting patients.Expert opinion: Much still needs to be done to render aggressive CNS tumors curable or at least to transform them from lethal to chronic diseases, as it is possible for other cancer types. Drugs with improved penetration in the CNS, toxicity profile, and activity against primary and recurrent tumors are eagerly needed. Targeted agents with innovative mechanisms of action and ability to harness the cells of the tumor microenvironment against cancer cells represent a promising approach for improving the clinical outcome of CNS tumors.

Recent Advances in Meningioma Immunogenetics

Meningiomas are relatively common, and typically benign intracranial tumors, which in many cases can be cured by surgical resection. However, less prevalent, high grade meningiomas, grow quickly, and recur frequently despite treatment, leading to poor patient outcomes. Across tumor grades, subjective guidelines for histological analysis can preclude accurate diagnosis, and an insufficient understanding of recurrence risk can cloud the choice of optimal treatment. Improved diagnostic and prognostic markers capable of discerning between the 15 heterogeneous WHO recognized meningioma subtypes are necessary to improve disease management and identify new targeted drug treatments. In this review, we show the advances in molecular profiling and immunophenotyping of meningiomas, which may lead to the development of new personalized therapeutic strategies.

En Plaque Meningiomas: A Narrative Review

Background  En plaque meningiomas are a rare subtype of meningiomas that are frequently encountered in the spheno-orbital region. Characterized by a hyperostotic and dural invasive architecture, these tumors present unique diagnostic and treatment considerations. Objective  The authors conduct a narrative literature review of clinical reports of en plaque meningiomas to summarize the epidemiology, clinical presentation, diagnostic criteria, and treatment considerations in treating en plaque meningiomas. Additionally, the authors present a case from their own experience to illustrate its complexity and unique features. Methods  A literature search was conducted using the MEDLINE database using the following terminology in various combinations: meningioma , meningeal neoplasms, en plaque , skull base , spheno-orbital, and sphenoid wing . Only literature published in English between 1938 and 2018 was reviewed. All case series were specifically reviewed for sufficient data on treatment outcomes, and all literature was analyzed for reports of misdiagnosed cases. Conclusion  En plaque meningiomas may present with a variety of symptoms according to their location and degree of bone invasion, requiring a careful diagnostic and treatment approach. While early and aggressive surgical resection is generally accepted as the optimal goal of treatment, these lesions require an individualized approach, with further investigation needed regarding the role of new therapies.

Biopsy proven metastatic meningioma: A case report and review of the literature

Meningiomas are the most common type of benign tumor found in the brain and are typically benign, slow-growing lesions. The current standard of care consists of surgical resection and subsequent postoperative radiotherapy to prevent local recurrence. Because of their indolent nature, meningiomas are rarely found to spread extracranially and develop distant metastases. We present the clinical, imaging, and pathologic features of a patient who had meningioma with multiple local recurrences, who was incidentally found to have metastatic disease in the lungs. In addition, we discuss details of this case in the context of the previously reported literature.

Initial management of meningiomas: Analysis of the National Cancer Database

BACKGROUND

Meningiomas are the most common central nervous system tumor. We describe current trends in treatment and survival using the largest cancer dataset in the United States.

METHODS

We analyzed the National Cancer Database from 2004 to 2014, for all patients with diagnosis of meningioma.

RESULTS

201,765 cases were analyzed. Patients were most commonly White (81.9%) females (73.2%) with a median age of 64 years. Fifty percent of patients were diagnosed by imaging. Patients were reported as grade I (24.9%), grade II (5.0%), grade III (0.7%), or unknown WHO grade (69.4%). Patients diagnosed by imaging were older, received treatment in community facilities, had higher Charlson-Deyo score, and a lower rate of private insurance. Watchful waiting was the most common treatment modality (46.7%), followed by surgery only (40%). Grade II and III patients were more likely to receive therapy. Watchful waiting increased from 35.2% in 2004 to 51.4% in 2014. Younger age, male gender, private insurance, and treatment in academic facilities were determinants for receipt of surgery and/or radiation. Median survival was 12.6 years, higher in histologically confirmed cases (13.1 years). Older patients, Blacks, males, those that received radiation plus surgery, and were treated in community facilities had an increased risk of mortality.

CONCLUSIONS

Over half of patients were diagnosed by imaging, suggesting a higher role of clinical determinants over histological confirmation in treatment decisions. Watchful waiting as initial management is increasing. Our survival analysis favored histological confirmation. Patients receiving radiation and surgery had an increased risk of mortality.