Metastasis to and from the central nervous system--the 'relatively protected site'

Myeloid Cells Induce Infiltration and Activation of B Cells and CD4+ T Follicular Helper Cells to Sensitize Brain Metastases to Combination Immunotherapy

Brain metastasis is a poor prognostic factor in patients with cancer. Despite showing efficacy in many extracranial tumors, immunotherapy with anti-PD-1 mAb or anti-CTLA4 mAb seems to be less effective against intracranial tumors. Promisingly, recent clinical studies have reported that combination therapy with anti-PD-1 and anti-CTLA4 mAbs has a potent antitumor effect on brain metastasis, highlighting the need to elucidate the detailed mechanisms controlling the intracranial tumor microenvironment (TME) to develop effective immunotherapeutic strategies. In this study, we analyzed the tumor-infiltrating lymphocytes in murine models of brain metastasis that responded to anti-CTLA4 and anti-PD-1 mAbs. Activated CD4+ T follicular helper (TFH) cells with high CTLA4 expression characteristically infiltrated the intracranial TME, which were activated by combination anti-CTLA4 and anti-PD-1 treatment. The loss of TFH cells suppressed the additive effect of CTLA4 blockade on anti-PD-1 mAb. B-cell-activating factor belonging to the TNF family (BAFF) and a proliferation-inducing ligand (APRIL) produced by abundant myeloid cells, particularly CD80hiCD206lo proinflammatory M1-like macrophages, in the intracranial TME induced B-cell and TFH-cell infiltration and activation. Furthermore, the intracranial TME of patients with non-small cell lung cancer featured TFH- and B-cell infiltration as tertiary lymphoid structures. Together, these findings provide insights into the immune cell cross-talk in the intracranial TME that facilitates an additive antitumor effect of CTLA4 blockade with anti-PD-1 treatment, supporting the potential of a combination immunotherapeutic strategy for brain metastases. Significance: B-cell and CD4+ T follicular helper cell activation via BAFF/APRIL from abundant myeloid cells in the intracranial tumor microenvironment enables a combinatorial effect of CTLA4 and PD-1 blockade in brain metastases.

Mesenchymal-Type Genetic Mutations Are Likely Prerequisite for Glioblastoma Multiforme to Metastasize Outside the Central Nervous System: An Original Case Series and Systematic Review of the Literature

BACKGROUND

Glioblastoma multiforme (GBM) is the most aggressive and prevalent type of malignant brain tumor, yet it metastasizes outside the central nervous system (CNS) in only 0.4% of cases. Little is known about what enables this subset of GBMs to take root outside the CNS, but genetic mutations likely play a role.

METHODS

We conducted a PRISMA-compliant systematic review of metastatic GBM wherein we reviewed 3579 search results and 1080 abstracts, analyzing data from 139 studies and 211 unique patients. In addition, we describe 4 cases of patients with pathologically confirmed GBM metastases outside the CNS treated at our institution.

RESULTS

We found that metastases were discovered near previous surgical sites in at least 36.9% of cases. Other sites of metastasis included bone (47.9%), lung (25.6%), lymph nodes (25.1%), scalp (19.2%), and liver (14.2%). On average, metastases were diagnosed 12.1 months after the most recent resection, and the mean survival from discovery was 5.7 months. In our patients, primary GBM lesions showed mutations in NF1, TERT, TP53, CDK4, and RB1/PTEN genes. Unique to the metastatic lesions were amplifications in genes such as p53 and PDGFRA/KIT, as well as increased vimentin and Ki-67 expression.

CONCLUSIONS

There is strong evidence that GBMs acquire novel mutations to survive outside the CNS. In some cases, tumor cells likely mutate after seeding scalp tissue during surgery, and in others, they mutate and spread without surgery. Future studies and genetic profiling of primary and metastatic lesions may help uncover the mechanisms of spread.

Exposed Phosphatidylserine as a Biomarker for Clear Identification of Breast Cancer Brain Metastases in Mouse Models

Brain metastasis is the most common intracranial malignancy in adults. The prognosis is extremely poor, partly because most patients have more than one brain lesion, and the currently available therapies are nonspecific or inaccessible to those occult metastases due to an impermeable blood-tumor barrier (BTB). Phosphatidylserine (PS) is externalized on the surface of viable endothelial cells (ECs) in tumor blood vessels. In this study, we have applied a PS-targeting antibody to assess brain metastases in mouse models. Fluorescence microscopic imaging revealed that extensive PS exposure was found exclusively on vascular ECs of brain metastases. The highly sensitive and specific binding of the PS antibody enables individual metastases, even micrometastases containing an intact BTB, to be clearly delineated. Furthermore, the conjugation of the PS antibody with a fluorescence dye, IRDye 800CW, or a radioisotope, 125I, allowed the clear visualization of individual brain metastases by optical imaging and autoradiography, respectively. In conclusion, we demonstrated a novel strategy for targeting brain metastases based on our finding that abundant PS exposure occurs on blood vessels of brain metastases but not on normal brain, which may be useful for the development of imaging and targeted therapeutics for brain metastases.

A comparative study of whole brain radiotherapy with concomitant thalidomide versus whole brain radiotherapy alone in brain metastases

BACKGROUND

Brain metastasis increases morbidity and mortality in cancer patients. This study was undertaken to compare tumor response and treatment-related toxicities in patients treated with orally administered thalidomide concomitantly with whole brain radiotherapy to whole brain radiotherapy alone in brain metastases.

METHODS

This randomized control trial was conducted in radiation oncology department, RIMS among 42 patients of brain metastases distributed in two study arms during the period August 2018 to July 2020. Twenty patients in Arm-A received whole brain radiotherapy to a dose of 3,750 cGy in 15 fractions with concomitant oral thalidomide 200 mg daily in first week and 400 mg/day from second week of radiation onward till the end of radiotherapy, whereas 20 patients of Arm-B received whole brain radiation of 3,750 cGy in 15 fractions alone.

RESULTS

Patient characteristics were comparable. Median central nervous system progression free survival was 2 months for Arm-A and 3 months for Arm-B, whereas median overall survival study was 4 months for Arm-A and 3 months for Arm-B. Overall response rate in Arm-A was 56% and in Arm-B was 44%. Treatment-related toxicities were more in arm-A but were manageable.

CONCLUSION

Addition of thalidomide to whole brain radiotherapy makes no significant difference. Though not statistically significant, but still, Arm-A had shown some percentage benefits. Further studies with larger sample sizes should be done.

Extracranial metastasis of brain glioblastoma outside CNS: Pathogenesis revisited

BACKGROUND

The most prevalent malignant tumor of the CNS in adults is glioblastoma. Despite undergoing surgery and chemoradiotherapy, the prognosis remains unfavorable, with a median survival period ranging between 15 and 20 months. The incidence of glioblastoma metastasis outside CNS is uncommon with only 0.4%-2% reported rate, compared to other tumors that exhibit a 10% incidence rate of metastasis to the brain. On average, it takes about 11 months from the time of initial diagnosis for the tumor to spread beyond CNS. Consequently, the prognosis for metastatic glioblastoma is grim, with a 6-month survival rate following diagnosis.

FINDINGS

The rarity of extracranial metastasis is attributed to the blood-brain barrier and lack of a lymphatic drainage system, although rare cases of hematogenous spread and direct implantation have been reported. The possible mechanisms remain unclear and require further investigation. Risk factors have been widely described, including previous craniotomy or biopsies, ventricular shunting, young age, radiation therapy, prolonged survival time, and tumor recurrence. Due to the lack of understanding about extracranial metastasis of glioblastoma pathogenesis, no effective treatment exists to date. Aggressive chemotherapies are not recommended for metastatic glioblastoma as their side effects may worsen the patient prognosis.

CONCLUSION

The optimal treatment for extracranial metastasis of glioblastoma requires further investigation with a wide inclusion of patients. This review discusses the possible causes, factors, and underlying mechanisms of glioblastoma metastasis to different organs.

Brain metastases of sarcoma: a rare phenomenon in rare tumours

The usual site for distant metastases of sarcoma is lungs, while brain metastasis (BM) occurs much less frequently and usually late in the disease progression. Despite the advancement in cancer treatment, the outcome for patients with brain metastasis is poor, and their lifespan is short. The frequency of BM in sarcoma seems to be affected by the location and histology of the primary tumour. Sarcoma subtypes with a high propensity for brain metastasis are ASPS, leiomyosarcoma and osteosarcoma. There are no clear guidelines for the treatment of sarcoma brain metastasis. However, therapeutic options include surgery, radiotherapy and chemotherapy, and are often combined. Targeted therapies are a promising treatment option for sarcoma but require investigation in patients with BM. The following review presents the data on sarcoma brain metastasis incidence, treatment and prognosis.

How to handle brain tumors after esophagectomy with curative intent: A single center 20-year experience

BACKGROUND

Brain metastases after esophagectomy are rare. Moreover, a diagnostic uncertainty remains as pathology is rarely obtained and radiological features can show similarities to primary brain tumors. Our aim was to demonstrate the diagnostic uncertainty and identify risk factors associated with brain tumors (BT) after esophagectomy with curative intent.

METHODS

All patients who underwent an esophagectomy with curative intent from 2000 to 2019 were reviewed. Diagnostics and characteristics of BT were analyzed. Multivariable logistic and cox regression were performed to determine factors associated with development of BT and survival, respectively.

RESULTS

In total, 2131 patients underwent esophagectomy with curative intent, of which 72 patients (3.4%) developed BT. Pathological diagnosis was obtained in 26 patients (1.2%), of which 2 patients were diagnosed with glioblastoma. On multivariate analysis, radiotherapy (OR, 7.71; 95%CI: 2.66-22.34, p < 0.001) was associated with an increased risk of BT and early-stage tumors (OR, 0.29; 95%CI: 0.10-0.90, p = 0.004) with a decreased risk of BT. Median overall survival was 7.4 months (95%CI: 4.80-9.96). BT treated with curative intent (surgery or stereotactic radiation) had a significantly better median overall survival (16 months; 95%CI: 11.3-20.7) compared to those without (3.7 months; 95%CI: 0.9-6.6, p < 0.001) CONCLUSIONS: Advanced stage tumors and radiotherapy seem related to the development of brain tumors after esophagectomy with curative intent. However, an important diagnostic uncertainty remains in these patients as pathological diagnosis is only obtained in a minority of cases. Tissue confirmation can be useful to inform a patient-tailored multimodality treatment strategy in select patient.

CCKAR is a biomarker for prognosis and asynchronous brain metastasis of non-small cell lung cancer

Background

Non-small cell lung cancer (NSCLC) is the most common histological type of lung cancer, and brain metastasis (BM) is the most lethal complication of NSCLC. The predictive biomarkers and risk factors of asynchronous BM are still unknown.

Materials and methods

A total of 203 patients with NSCLC were enrolled into our cohort and followed up. The clinicopathological factors such as tumor size, T stage, lymphatic invasion, metastasis and asynchronous BM were investigated. CCKAR expression in NSCLC and resected BM was assessed by IHC, and CCKAR mRNAs in NSCLC and para-tumor tissues were estimated by qRT-PCR. The correlations between CCKAR expression, BM and other clinicopathological factors were assessed by chi-square test, and prognostic significance of CCKAR was estimated by univariate and multivariate analyses.

Results

CCKAR was highly expressed in NSCLC tissues compared with para-tumor tissues. CCKAR expression in NSCLC was significantly associated with asynchronous BM. The BM percentages for NSCLC patients with low and high CCKAR were surprisingly 5.2% and 66.6%, respectively. CCKAR expression and BM were unfavorable factors predicting unfavorable outcome of NSCLC. Moreover, CCKAR expression in NSCLC was an independent risk factor of asynchronous BM.

Conclusions

CCKAR is a prognostic biomarker of NSCLC. CCKAR expression in NSCLC is positively associated with asynchronous BM, and is a risk factor of asynchronous BM from NSCLC.

WDR5 is a prognostic biomarker of brain metastasis from non-small cell lung cancer

Background

Lung cancer (LC) is the most frequent caner type and causes the most cancer-related death. Brain metastases (BM) are the deadliest complications of lung cancer, and the prognostic biomarkers of BM are urgently needed.

Materials and methods

In our study, we established an inception cohort including 122 patients with asynchronous BM from NSCLC, and further selected 70 patients who received surgical resection, which compromised the validation cohort. With immunohistochemistry, we investigated the expression of WDR5 in the cohort. By chi-square method, the correlations between WDR5 and clinicopathological factors were analyzed. The prognostic indicators were analyzed with the univariate analysis, and independent prognostic factors were identified by multivariate analysis with Cox-regression model.

Results

WDR5 is frequently expressed in the cytoplasm of BM from NSCLC. Patients with low or high expression of WDR5 account for 60% and 40% respectively. High expression of WDR5 indicates poor prognosis of BM from NSCLC (P=0.001). In addition to WDR5, KPS is also a prognostic factor of BM, and high KPS predicts favorable prognosis (P=0.006). WDR5 is an independent prognostic biomarker for poor prognosis of BM from NSCLC, with the cancer-related odds as 2.48.

Conclusions

High expression of WDR5 can predict the poor prognosis of BM, and WDR5 is an independent prognostic biomarker of BM from NSCLC. Patients with WDR5 overexpression are more high-risk to suffer BM-related death and should receive more intense post-operational supervision.

Risk factors of extraneural spreading in astrocytomas and oligodendrogliomas in donors with gliomas: A systematic review

BACKGROUND

Patients with a history of primary brain tumors can be eligible for organ donation under extended criteria. The risk assessment of tumor transmission via organ transplant in primary brain tumors is primarily based on the assessment of tumor histotype and grade. Previous surgeries, chemo-/radiotherapy, and ventriculo-peritoneal shunt placement can lead to a disruption of the blood-brain barrier, concurring to an increase in the transmission risk.

AIM

To investigate the role of tumor transmission risk factors in donors with oligodendrogliomas and astrocytomas.

METHODS

We searched PubMed and EMBASE databases for studies reporting extraneural spreading of oligodendrogliomas and astrocytomas and extracted clinical-pathological data on the primary tumor histotype and grade, the elapsed time from the diagnosis to the onset of metastases, sites and number of metastases, prior surgeries, prior radiotherapy and/or chemotherapy, ventriculo-atrial or ventriculo-peritoneal shunt placement, and the presence of isocitrate dehydrogenase 1/2 mutation and 1p/19q codeletion. Statistical analysis was performed using R software. Statistical correlation between chemotherapy or radiotherapy and the presence of multiple extra-central nervous system metastases was analyzed using χ 2 and Fischer exact test. The Kaplan-Meier method was used to evaluate the presence of a correlation between the metastasis-free time and: (1) Localization of metastases; (2) The occurrence of intracranial recurrences; and (3) The occurrence of multiple metastases.

RESULTS

Data on a total of 157 patients were retrieved. The time from the initial diagnosis to metastatic spread ranged from 0 to 325 mo in patients with oligodendrogliomas and 0 to 267 mo in those with astrocytomas. Respectively, 19% and 39% of patients with oligodendroglioma and astrocytoma did not receive any adjuvant therapy. The most frequent metastatic sites were bone, bone marrow, and lymph nodes. The lungs and the liver were the most commonly involved visceral sites. There was no significant correlation between the occurrence of multiple metastases and the administration of adjuvant chemo-/radiotherapy. Patients who developed intracranial recurrences/metastases had a significantly longer extraneural metastasis-free time compared to those who developed extraneural metastases in the absence of any intra- central nervous system spread.

CONCLUSION

A long follow-up time does not exclude the presence of extraneural metastases. Therefore, targeted imaging of bones and cervical lymph nodes may improve safety in the management of these donors.

TP53 Mutation and Extraneural Metastasis of Glioblastoma: Insights From an Institutional Experience and Comprehensive Literature Review

Extraneural metastases of glioblastoma (GBM), although rare, are becoming an increasingly recognized occurrence. Currently, the biological mechanism underlying this rare occurrence is not understood. To explore the potential genomic drivers of extraneural metastasis in GBM, we present the molecular features of 4 extraneural metastatic GBMs, along with a comprehensive review and analysis of previously reported cases that had available molecular characterization. In addition to our 4 cases, 42 patients from 35 publications are reviewed. To compare the molecular profiles between GBM cases with extraneural metastasis and the general GBM population, genomic data from GBM samples in The Cancer Genome Atlas (TCGA) database were also analyzed. We found that 64.5% (20/31) of the cases with extraneural metastasis that were tested for TP53 changes had at least 1 TP53 pathogenic variant detected in either 1 or both primary and metastatic tumors. In contrast, TP53 mutation was significantly less frequent in the unselected GBM from TCGA (22.6%, 56/248) (P=0.000). In addition, O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation was more common in unselected TCGA GBM cases (48.6%, 170/350) than in cases with extraneural metastasis (31.8%, 7/22), although not statistically significant. Although isocitrate dehydrogenase (IDH) mutation is a rare occurrence in high-grade astrocytomas, IDH-mutant grade 4 astrocytomas are at least as likely to metastasize as IDH wild-type GBMs; 3 metastatic cases definitively harbored an IDH1 (p.R132H) mutation in our analysis. Our findings not only provide potential biomarkers for earlier screening of extraneural metastasis, but could also suggest clues to understanding biological mechanisms underlying GBM metastasis, and for the development of therapeutic modalities.

Cytology of Extraneural Metastases of Nonhematolymphoid Primary Central Nervous System Tumors: Six Cases with Histopathological Correlation and Literature Update

INTRODUCTION

Extraneural/-cranial metastases (ENM) of primary central nervous system (CNS) tumors are rare and may be diagnostically challenging. We describe the cytomorphological and pertinent clinical features of ENM in a case series assessed by fine-needle aspiration (FNA). A search of the laboratory information systems of 2 tertiary care centers in Toronto (2000-2015) was performed. Cases with direct extracranial/-spinal extension of CNS neoplasms were excluded. Microscopic slides of FNA and surgical specimens were reviewed. Demographic and clinicopathological data were retrieved.

CASE PRESENTATION

Six cases were identified with the original diagnoses of glioblastoma, glioblastoma with primitive neuroectodermal tumor-like components, anaplastic ependymoma, myxopapillary ependymoma, atypical meningioma, and hemangiopericytoma. Median patient age at first diagnosis was 44 years (range 22-56). The time interval between initial diagnosis and first metastatic disease manifestation was 3 months to 19 years. All FNA diagnoses were rendered correctly. In 4 cases, immunohistochemistry was used to support the diagnosis. All cases had prior surgical intervention at the primary tumor site. In 4 cases, the ENM location was the ipsilateral parotid or buccal area. Two primary tumors in midline location developed ENM in the scapular area.

DISCUSSION/CONCLUSION

ENM are a rare manifestation of a range of different primary CNS tumors and may involve the ipsilateral head and neck mimicking clinically a salivary gland neoplasm. FNA can rapidly discriminate ENM from other, potentially more indolent conditions. Awareness of the clinical history is paramount to avoid diagnostic confusion.

HOXB9 enhances the ability of lung cancer cells to penetrate the blood-brain barrier

Even after multimodal therapy, the prognosis is dismal for patients with brain metastases from non-small cell lung cancer (NSCLC). Although the blood-brain barrier (BBB) limits tumor cell penetration into the brain parenchyma, some nevertheless colonize brain tissue through mechanisms that are not fully clear. Here we show that homeobox B9 (HOXB9), which is commonly overexpressed in NSCLC, promotes epithelial-to-mesenchymal transition (EMT) and tumor migration and invasion. Animal experiments showed that HOXB9 expression correlates positively with the brain metastatic potential of human NSCLC cells, while brain metastatic cells derived through in vivo selection showed greater HOXB9 expression than their cells of origin. Comparable results were obtained after immunohistochemical analysis of clinical primary NSCLC and matched brain metastasis samples obtained after surgery. Using an in vitro BBB model, knockdown and overexpression experiments showed that HOXB9-dependent expression of MMP9 in NSCLC cells leads to reduced expression of junctional proteins in cultured human vascular endothelial cells and enhanced transmigration of tumor cells. These data indicate that HOXB9 enables NSCLC cells to break away from the primary tumor by inducing EMT, and promotes brain metastasis by driving MMP9 production and degradation of intercellular adhesion proteins in endothelial cells comprising the BBB.

Solitary vertebral metastatic glioblastoma in the absence of primary brain tumor relapse: a case report and literature review

BACKGROUND

Metastatic glioblastoma presenting as a solitary osteolytic cervical vertebral mass without primary brain tumor relapse is extremely rare with only 1 reported case in the literature. Because of its rarity, it can be easily overlooked and misdiagnosed, posing a diagnostic dilemma.

CASE PRESENTATION

A 51-year-old man with right temporal glioblastoma was initially treated by tumor resection, radiotherapy and chemotherapy. Eighteen months after surgery, he was readmitted with complaints of neck pain for 2 weeks. Follow-up magnetic resonance imaging (MRI) and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed a solitary FDG-avid osteolytic lesion in the 4th cervical vertebral body without other abnormal FDG-uptake in the body and in the absence of local recurrence at the resection cavity. Because of the sudden worsening situation and intractable neck pain, the patient underwent tumor resection. Postoperatively, the pain was obviously reduced and the situation was improved. Interestingly, the immunohistochemical findings of glial fibrillary acidic protein (GFAP) indicated the characteristic of metastatic glioblastoma, despite that the histopathological findings of Hematoxylin & Eosin (H&E) staining was suspicious of osteoclastoma. According to the clinical history, imaging findings, pathological and immunohistochemical results, a final diagnosis of solitary vertebral metastasis from glioblastoma without central nervous system (CNS) relapse was confirmed. Then, the patient received radiotherapy on spine and adjuvant chemotherapy with temozolomide. However, he died suddenly 2 months after the tumor resection, nearly 21 months after the initial diagnosis.

CONCLUSION

We emphasize that metastatic glioblastoma should be considered in the differential diagnosis of a solitary FDG-avid osteolytic vertebral mass on PET/CT. And the diagnosis of extracranial metastasis (ECM) from glioblastoma can be achieved through clinical history, imaging findings, pathological examination, and immunohistochemical staining with GFAP.

Extensive systemic metastases from primary central nervous system haemangiopericytoma

Primary intracranial tumours rarely metastasise outside of the central nervous system (CNS). This report describes a rare case of recurrent meningeal haemangiopericytoma with extensive systemic metastases, which eventually resulted in a fatal outcome. We discuss some prevailing theories as to the rarity of extracranial metastases from primary CNS haemangiopericytoma, and elucidate the epidemiology, imaging features, differential diagnosis, treatment, and prognosis of this unusual but surprisingly aggressive meningeal tumour. Besides aggressive treatment for local tumour control, patients with primary CNS haemangiopericytoma require long-term post-treatment surveillance to detect systemic metastases.

Extraneural metastatic paediatric glioblastoma: Case report and literature review

The incidence of paediatric glioblastoma is uncommon in comparison to their adult counterpart. Even more infrequent are extraneural metastases in glioblastoma. A previously well 14-year-old female presented with progressive right hemiparesis secondary to a left fronto-temporal lobe glioblastoma (WHO IV). She underwent successful gross total resection for her brain tumour. Prior to commencement of her adjuvant treatment, she developed tumour recurrence associated with intra-lesional haemorrhage. Although she underwent a second surgery, the patient developed bilateral malignant pleural effusion secondary to extraneural pulmonary metastases. Early awareness of its existence enables prompt diagnosis for this devastating disease. The authors emphasize the urgent need for international collaborations to work together for children affected by this challenging brain tumour.

Development and validation of a five-gene model to predict postoperative brain metastasis in operable lung adenocarcinoma

One of the most common sites of extra-thoracic distant metastasis of nonsmall-cell lung cancer is the brain. Our study was performed to discover genes associated with postoperative brain metastasis in operable lung adenocarcinoma (LUAD). RNA seq was performed in specimens of primary LUAD from seven patients with brain metastases and 45 patients without recurrence. Immunohistochemical (IHC) assays of the differentially expressed genes were conducted in 272 surgical-resected LUAD specimens. LASSO Cox regression was used to filter genes related to brain metastasis and construct brain metastasis score (BMS). GSE31210 and GSE50081 were used as validation datasets of the model. Gene Set Enrichment Analysis was performed in patients stratified by risk of brain metastasis in the TCGA database. Through the initial screening, eight genes (CDK1, KPNA2, KIF11, ASPM, CEP55, HJURP, TYMS and TTK) were selected for IHC analyses. The BMS based on protein expression levels of five genes (TYMS, CDK1, HJURP, CEP55 and KIF11) was highly predictive of brain metastasis in our cohort (12-month AUC: 0.791, 36-month AUC: 0.766, 60-month AUC: 0.812). The validation of BMS on overall survival of GSE31210 and GSE50081 also showed excellent predictive value (GSE31210, 12-month AUC: 0.682, 36-month AUC: 0.713, 60-month AUC: 0.762; GSE50081, 12-month AUC: 0.706, 36-month AUC: 0.700, 60-month AUC: 0.724). Further analyses showed high BMS was associated with pathways of cell cycle and DNA repair. A five-gene predictive model exhibits potential clinical utility for the prediction of postoperative brain metastasis and the individual management of patients with LUAD after radical resection.

[Spinal cord metastasis of anaplastic oligodendroglioma of the brain without recurrence of primary tumor. Ccase report and literature review]

Spinal cord metastases of brain gliomas are rare. However, incidence of these tumors has been increasing recently. The vast majority of neurosurgeons and oncologists recognize spinal cord metastasis of malignant brain glioma followed by symptoms of transverse spinal cord lesion as non-curable terminal stage of malignant process. In this paper, we report a rare clinical case of metastatic spinal cord lesion in a patient after previous surgery for anaplastic oligodendroglioma of the right frontal lobe. There were no signs of local recurrence of the primary tumor. Active surgical strategy followed by radio- and chemotherapy significantly improved the patient's quality of life. Postoperative follow-up is 6 months by the moment of writing the manuscript, no clinical signs of progression are observed.

Advances in the management of brain metastases from cancer of unknown primary

Cancer of unknown primary accounts for 3-5% of all cancers for which an adequate investigation does not identify the primary tumor. The particular subset of brain metastasis in cancer of unknown primary (BMCUP) is a clinical challenge that lacks standardized diagnostic and therapeutic options. It is diagnosed predominantly in male patients in the sixth decade of age with complaints of headache, neurological dysfunction, cognitive and behavioral disturbances and seizures. The therapeutic approach to patients with BMCUP relies on local control and systemic treatment. Surgery or stereotactic radiosurgery and/or whole brain radiation therapy seems to be the cornerstone of the treatment approach to BMCUP. Systemic therapy remains essential as cancers of unknown primary are conceptually metastatic tumors. The benefits of chemotherapy were disappointing whereas those of targeted therapies and immune checkpoint inhibitors remain to be evaluated. In this Review, we address the advances in the diagnosis and treatment of BMCUP.

Incidence of metastatic disease and survival among patients with newly diagnosed primary CNS tumors in the United States from 2004-2013

Background: Population-based estimates of the incidence and prognosis of metastatic disease at the initial diagnosis of primary central nervous system (CNS) tumors are currently lacking.

Methods: A total of 43,455 patients diagnosed with a primary CNS tumor were enrolled to evaluate metastatic rates utilizing the data from the Surveillance, Epidemiology, and End Results (SEER) program. We used multivariate logistic regression to analyze the risk factors associated with the presence of metastasis at the first visit of patients with metastatic medulloblastoma (MB), atypical teratoid/rhabdoid tumor (ATRT), glioblastoma multiforme (GBM), or pilocytic astrocytoma (PA). Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer-specific death (CSD) of patients with these four CNS tumors were analyzed using multivariate Cox regression.

Results: In patients with primary CNS embryonal tumors, the metastatic rates of patients with MB and ATRT were 14.51% and 19.25%, respectively. The metastatic rate for MB patients aged 0 to 18 years was 16.69%. In the patients with glioma, the metastatic rates of patients with PA and GBM were 1.55% and 1.39%, respectively. On multivariate logistic regression among patients with glioma, GBM (vs PA; OR, 2.12; 95% CI, 1.37 to 3.30; P=0.001) was associated with greater odds of having metastatic disease at diagnosis. On multivariate logistic regression among patients with GBM, MB, or ATRT, MB (vs GBM; OR, 4.66; 95% CI, 2.81 to 7.72; P<0.001) and ATRT (vs GBM; OR, 5.65; 95% CI, 3.27 to 9.75; P<0.001) were associated with greater odds of having metastatic disease at diagnosis. In the multivariate Cox proportional hazards model for CSD among patients with metastatic GBM or MB at diagnosis, gross total resection/total lobectomy (vs partial resection/partial lobectomy) was not related to a decreased or an increased risk of CSD. In patients with metastatic ATRT, compared to no surgery, gross total resection/total lobectomy or partial resection/partial lobectomy was not associated with a decreased risk of CSD.

Conclusions: The findings in this study provide a population-based estimate of the incidence and prognosis of metastatic disease at the initial diagnosis of primary CNS tumors. These survival outcomes are relevant because they will help to prioritize future research directions to improve the treatment strategies of these metastatic CNS tumors.

Somatic mutation landscape of a meningioma and its pulmonary metastasis

Background

Extracranial metastasis (ENM) of meningiomas is extremely rare, and typically occurs several years after a primary tumor is diagnosed. However, the genetic changes underlying ENM events have not yet been investigated.

Case presentation

A 58-year-old male patient was sent to the emergency room of our hospital because of a sudden fall. Magnetic resonance imaging detected a mass at the right frontal sagittal sinus. He underwent tumor resection and recovered well, but post-operative computed tomography revealed three lumps on the right side of his chest. Thoracic surgery was performed to remove two of the lumps. Pathological findings revealed that the brain and lung tumors were grade I meningiomas. The patient received no additional radiation or chemotherapy post-surgery, and there was no sign of tumor recurrence in the brain or progression of the remaining lump in the chest 1 year after surgery. We performed whole exome sequencing of the patient’s blood, primary brain tumor, and lung metastatic tumor tissues to identify somatic genetic alterations that had occurred during ENM. This revealed that a frameshift deletion of the neurofibromin 2 gene likely drove formation of the meningioma. Surprisingly, we found that the brain tumor was relatively homogeneous and contained only one dominant clone; both the pulmonary metastasis and the original brain tumor were derived from the same clone, and no obvious additional driver mutations were detected in the metastatic tumor.

Conclusion

Although ENM of meningiomas is very rare, brain tumor cells appear to be more adaptable to tissue microenvironments outside of the central nervous system than was commonly thought.

Glycosylation Changes in Brain Cancer

Protein glycosylation is a posttranslational modification that affects more than half of all known proteins. Glycans covalently bound to biomolecules modulate their functions by both direct interactions, such as the recognition of glycan structures by binding partners, and indirect mechanisms that contribute to the control of protein conformation, stability, and turnover. The focus of this Review is the discussion of aberrant glycosylation related to brain cancer. Altered sialylation and fucosylation of N- and O-glycans play a role in the development and progression of brain cancer. Additionally, aberrant O-glycan expression has been implicated in brain cancer. This Review also addresses the clinical potential and applications of aberrant glycosylation for the detection and treatment of brain cancer. The viable roles glycans may play in the development of brain cancer therapeutics are addressed as well as cancer-glycoproteomics and personalized medicine. Glycoprotein alterations are considered as a hallmark of cancer while high expression in body fluids represents an opportunity for cancer assessment.

Cerebellar metastases – may surgery play a role in the presence of multiple lesions?

Brain metastases are the most common form of malignancy presence in the CNS having a more frequent appearance than primary brain tumors. Although secondary cerebellar tumors represent only 15% of all intracranial metastases, they are quite frequent among primary oncological patients and pose a challenge for all of the medical caretakers starting with the neurosurgeon. Among those, a small percent of patients have multiple cerebellar lesions and the therapeutic challenge turns into a medical controversy, especially when it comes to surgical treatment taking into consideration that the life expectancy is lower than one year. A key asset which we have on our side is the anatomical vicinity these lesions occur, this leading us to take into consideration eliminating as many lesions in one single operative time as possible without changing the position of the head during surgery. Based on a retrospective study which concluded that patients with resection of all lesions tend to have a longer life expectancy, and on modern concepts of risks and benefits of oncological surgery and surgery in general, we followed up on three patients presenting posterior and even multiple posterior fossa metastases, taking into consideration individual comorbidities, tumor aspects and the possibility/opportunity of surgical treatment. It turned out that surgery is a safe and effective treatment option and should not be considered harmful or aggressive especially because all of the patients which were under study had a favorable post-operative prognostic and an improved quality of life. We emphasize furthermore the importance of complete lesion resection in as few interventions as possible followed up by radiotherapy/chemotherapy as a key in prolonging these patients life expectancy taking into consideration that the outcome is directly related to the number of lesions rather to the location or volume of them.

Extracranial bone metastases from recurrent anaplastic astrocytoma on FDG PET/CT: A case report a care-compliant article

OBJECTIVE

Extracranial bone metastases from astrocytoma are rare and frequently detected as part of multiorgan metastases. It is extremely rare for astrocytoma to have extracranial bone metastases alone. The importance of whole-body fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging in evaluating extracranial metastasis (ECMs) has not been described effectively due to the rarity of this event. The purpose of our case report is to emphasize the role of FDG PET/CT in the assessment of tumor recurrence and extracranial bone metastases from anaplastic astrocytoma.

METHODS AND MATERIALS

A 25-year-old woman was firstly admitted with a 4-month history of progressive blurred vision, and 2-month history of intermittent headache. Presurgical MRI imaging revealed a large mass in the left trigone of lateral ventricle. Subsequently, she underwent tumor resection, radiotherapy and chemotherapy. A final pathological diagnosis of anaplastic astrocytoma (WHO III) was made. Nearly 12 months after the surgery, the follow-up brain MR imaging revealed a contrast-enhanced lesion in the site of operative region. Whole-body FDG PET/CT imaging was performed to evaluate the situation.

RESULTS

Postoperative brain FDG PET/CT showed an abnormal focal FDG uptake corresponding to the contrast-enhanced lesion in the operative area, suggesting a tumor recurrence. Whole-body FDG PET/CT also showed multiple FDG-avid osteosclerotic lesions in the body. It was highly suggestive of extracranial bone metastases. A subsequent open bone biopsy of FDG-avid lesion in right iliac crest was performed. Histopathological and immunohistochemical findings indicated characteristic of glioma. The patient died 1 month later, nearly 13 months after the initial diagnosis.

CONCLUSIONS

ECMs from anaplastic astrocytoma are extremely rare but they do occur. Whole-body FDG PET/CT imaging with inclusion of brain was valuable in differentiating tumor recurrence from radiation necrosis and in detecting uncommon extracranial bone metastases from anaplastic astrocytoma, which were closely related to prognosis of this disease.

[Recommendations for the organ donation from patients with brain or medullary primitive tumors on behalf of the Association of the Neuro-oncologists of French Expression (ANOCEF) and the Club of Neuro-oncology of the French Society of Neurosurgery]

Requests of organs to be transplanted increase. As a matter of urgency, it is not always easy to decide if a patient carrier of a brain tumor can be candidate in the donation. After a review of the literature, the members of the Association of the Neuro-oncologists of French Expression (ANOCEF) and the Club of Neuro-oncology of the French Society of Neurosurgery propose consensual recommendations in case of donor carrier of primitive tumor intra-cranial or intra-medullary. A contact with the neuro-oncologist/neurosurgeon will allow to discuss the indication in case of glioma of grade I/II/III, according to the grade, the current status (absence of progressive disease), the number of surgeries and of lines of treatment. The taking is disadvised in case of glioma of grade IV (glioblastoma), of lymphoma or meningioma of grade III. No contraindication for the meningiomas of grade I, and individual discussion for the meningiomas of grade II. It is advisable to remain careful in case of hemangiopericytoma and of meningeal solitary fibrous tumor. The patients in first complete remission of a medulloblastoma or intra-cranial primitive germinoma seem good candidates for the taking of organ if the follow-up is of at least 10 years (3 years for non germinomas). In every case, a multidisciplinary discussion is desirable when it is materially possible.

The Thr300Ala variant of ATG16L1 is associated with decreased risk of brain metastasis in patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) often metastasizes to the brain, but identifying which patients will develop brain metastases (BM) is difficult. Macroautophagy/autophagy is critical for cancer initiation and progression. We hypothesized that genetic variants of autophagy-related genes may affect brain metastases (BM) in NSCLC patients. We genotyped 16 single nucleotide polymorphisms (SNPs) in 7 autophagy-related (ATG) genes (ATG3, ATG5, ATG7, ATG10, ATG12, ATG16L1, and MAP1LC3/LC3) by using DNA from blood samples of 323 NSCLC patients. Further, we evaluated the potential associations of these genes with subsequent BM development. Lung cancer cell lines stably transfected with ATG16L1: rs2241880 (T300A) were established. Mouse models of brain metastasis were developed using cells transfected with ATG16L1-300T or ATG16L1-300A. ATG10: rs10036653 and ATG16L1: rs2241880 were significantly associated with a decreased risk of BM (respective hazard ratios [HRs]=0.596, 95% confidence interval [CI] 0.398-0.894, P = 0.012; and HR = 0. 655, 95% CI 0.438-0.978, P = 0.039, respectively). ATG12: rs26532 was significantly associated with an increased risk of BM (HR=1.644, 95% CI 1.049-2.576, P = 0.030). Invasion and migration assays indicated that transfection with ATG16L1-300T (vs. 300A) stimulated the migration of A549 cells. An in vivo metastasis assay revealed that transfection with ATG16L1-300T (vs. 300A) significantly increased brain metastasis. Our results indicate that genetic variations in autophagy-related genes can predict BM and that genome analysis would facilitate stratification of patients for BM prevention trials.

Osteosclerosis Secondary to Metastatic Oligodendroglioma

This paper reviews a case of metastatic 1p/19q codeleted oligodendrioglioma causing diffuse osteosclerosis and pain. Primary central nervous system (CNS) tumors rarely metastasize outside the CNS, and metastatic oligodendroglioma is rarer still. The patient in this study had relief of pain after being treated with temozolomide. We discuss this rare presentation and potential treatment options, and review the literature in regards to metastatic oligodendrogliomas.

Emerging circulating biomarkers in glioblastoma: promises and challenges

Glioblastoma (GBM) is the most common and devastating primary malignant brain tumor in adults. The past few years have seen major progress in our understanding of the molecular basis of GBM. These advances, which have contributed to the development of novel targeted therapies, will change the paradigms in GBM therapy from disease-based to individually tailored molecular target-based treatment. No validated circulating biomarkers have yet been integrated into clinical practice for GBM. There is thus a critical need to implement minimally invasive clinical tests enabling molecular stratification and prognosis assessment, as well as the prediction and monitoring of treatment response. After examination of data from recent studies exploring several categories of tumor-associated biomarkers (circulating tumor cells, extracellular vesicles, nucleic acids and oncometabolites) identified in the blood, cerebrospinal fluid and urine, this article discusses the challenges and prospects for the development of circulating biomarkers in GBM.

Brain Metastases from Solid Tumors: an Institutional Study from South India

BACKGROUND

Brain metastases are the most common intra-cranial neoplasms. The incidence is on a rise due to advanced imaging techniques.

AIMS

The objective of the study was to analyse the clinical and demographic profile of patients with brain metastases from primary solid tumors.

MATERIALS AND METHODS

This is a retrospective single institutional study covering 130 consecutive patients with brain metastases from January 2007 to August 2014.

RESULTS

Some 64.6% of the patients were females. The majority were in the sixth decade of life. The site of the primary tumor was the lungs in 50.8% of the cases. The overall median time from the diagnosis of the primary malignancy to detection of brain metastases was 21.4 months. Survival was found to be significantly improved in patients with solitary brain lesions when compared to patients with multiple brain metastases, and in patients undergoing surgical excision with or without cranial irradiation when compared to whole brain irradiation alone. The majority of the cases belonged to the recursive partitioning analysis class II group. Whole brain radiation therapy was delivered to 79% of the patients.

CONCLUSIONS

Most of the patients with brain metastases in the study belonged to recursive partitioning analysis classes II or III, and hence had poor prognosis. Most of the patients in the Indian context either do not satisfy the indications for surgical excision or are incapable of bearing the high cost associated with stereotactic radiosurgery. Treatment should be tailored on an individual basis to all these patients.

Brain metastases in patients diagnosed with a solid primary cancer during childhood: experience from a single referral cancer center

OBJECT

Metastasis to the brain is frequent in adult cancer patients but rare among children. Advances in primary tumor treatment and the associated prolonged survival are said to have increased the frequency of brain metastasis in children. The authors present a series of cases of brain metastases in children diagnosed with a solid primary cancer, evaluate brain metastasis trends, and describe tumor type, patterns of occurrence, and prognosis.

METHODS

Patients with brain metastases whose primary cancer was diagnosed during childhood were identified in the 1990-2012 Tumor Registry at The University of Texas M.D. Anderson Cancer Center. A review of their hospital records provided demographic data, history, and clinical data, including primary cancer sites, number and location of brain metastases, sites of extracranial metastases, treatments, and outcomes.

RESULTS

Fifty-four pediatric patients (1.4%) had a brain metastasis from a solid primary tumor. Sarcomas were the most common (54%), followed by melanoma (15%). The patients' median ages at diagnosis of the primary cancer and the brain metastasis were 11.37 years and 15.03 years, respectively. The primary cancer was localized at diagnosis in 48% of patients and disseminated regionally in only 14%. The primary tumor and brain metastasis presented synchronously in 15% of patients, and other extracranial metastases were present when the primary cancer was diagnosed. The remaining patients were diagnosed with brain metastasis after initiation of primary cancer treatment, with a median presentation interval of 17 months after primary cancer diagnosis (range 2-77 months). At the time of diagnosis, the brain metastasis was the first site of systemic metastasis in only 4 (8%) of the 51 patients for whom data were available. Up to 70% of patients had lung metastases when brain metastases were found. Symptoms led to the brain metastasis diagnosis in 65% of cases. Brain metastases were single in 60% of cases and multiple in 35%; 6% had only leptomeningeal disease. The median Kaplan-Meier estimates of survival after diagnoses of primary cancer and brain metastasis were 29 months (95% CI 24-34 months) and 9 months (95% CI 6-11 months), respectively. Untreated patients survived for a median of 0.9 months after brain metastasis diagnosis (95% CI 0.3-1.5 months). Those receiving treatment survived for a median of 8 months after initiation of therapy (95% CI 6-11 months).

CONCLUSIONS

The results of this study challenge the current notion of an increased incidence of brain metastases among children with a solid primary cancer. The earlier diagnosis of the primary cancer, prior to its dissemination to distant sites (especially the brain), and initiation of presumably more effective treatments may support such an observation. However, although the actual number of cases may not be increasing, the prognosis after the diagnosis of a brain metastasis remains poor regardless of the management strategy.

Metastasis in central nervous system: Clinicopathological study with review of literature in a tertiary care center in South India

BACKGROUND

Secondary central nervous system (CNS) tumors are common in Western countries, but in Indian literature, scant data are available. With the advent of newer imaging techniques, the confirmatory histopathological diagnosis has become comparatively easier. Hereby, we have analyzed our data from a single tertiary care center in south India.

MATERIALS AND METHODS

In this retrospective study from January 2000 to December 2010, histopathologically diagnosed secondary CNS tumors were reviewed along with clinical, imaging, and relevant immunohistochemical findings. Meningeal, lymphoproliferative, and myeloproliferative tumors and autopsy data were not included in the study group.

RESULTS

There were 40 secondary CNS tumors. Male to female ratio was 2.3:1. Age range was wide (28-75 years). Majority of cases were seen in the fourth and fifth decade. Imaging-wise, (computed tomography and magnetic resonance imaging) majority were single lesions (n = 34, 85%). Most commonly, these single lesions were present in the cerebral hemisphere (n = 20, 50%) followed by cerebellum (n = 10, 25%). Adenocarcinoma accounted for maximum number of cases (n = 25, 62.5%) with lungs being the most common primary.

CONCLUSION

We have noted 25% metastatic adenocarcinomas in cerebellar location, which is higher when compared with available world literature. However, we also encountered a good number of cases (30%) due to unknown primary. Though histopathological examination with use of immunohistochemical markers can reliably distinguish primary from secondary CNS tumors in addition to available clinical and imaging data, particularly in developing countries, still a better work-up with an array of immunohistochemical markers and newer imaging modalities is desirable.

Occipital anaplastic oligodendroglioma with multiple organ metastases after a short clinical course: a case report and literature review

Background

It is generally believed that malignant gliomas never metastasize outside the central nervous system (CNS). However, the notion that oligodendrogliomas (OGDs) cells cannot spread outside CNS is being challenged.

Methods

We described in detail the clinical story of one patient with anaplastic OGD, which metastasized to lymph nodes, bone marrowand bones Genetic analyses included detection of 1p and 19q chromosomal arms, methylation status of MGMT promoter, and PTEN exon mutations. A search of worldwide literature was conducted for reports of metastatic OGDs using NCBI-PubMed, with the keywords “extracranial”, “extraneural”, “oligodendroglioma”, “oligodendrogliomas”, “metastatic”, “metastasis”, and “metastases”, in different combinations.

Results

An open biopsy of the infiltrated bones in our patient revealed that malignant cells had replaced the patient’s marrow. Moreover, the diagnosis of multiple-organ metastases of anaplastic OGD was confirmed based on immunohistochemical staining. Genetic analyses showed that the tumors originated from previously resected brain lesions. None of the lesions had 1p and 19q deletions, but hypermethylation of MGMT promoter, and the G → A transversion at codon 234 of PTEN exon 2 were detected. Literatures review yielded 60 reports of metastatic OGDs from 1951 to the present, which with our patient makes 61 cases. Concerning these 61 patients, there were 110 infiltrated sites correlated closely with primary OGDs. The most frequent metastatic sites were bone and bone marrow (n = 47; 42.7%), lymph nodes (n = 22; 20.0%), liver (n = 7; 6.4%), scalp (n = 6; 5.5%), lung (n = 6; 5.5%), pleura (n = 4; 3.6%), chest wall (n = 3; 2.7%), iliopsoas muscle (n = 2; 1.8%), soft tissue (n = 2; 1.8%), and parotid gland (n = 2; 1.8%).

Conclusions

Extracranial metastases in anaplastic OGD are very rare but they do occur; bone and bone marrow may be the most common sites. Detection of certain molecular markers such as deletion of 1p and 19q chromosomal arms, hypermethylation of MGMT promoter, and characteristic PTEN exon mutations may help differentiate subtypes which are more prone to extracranial metastases.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8749838611478560.

Toward 3D biomimetic models to understand the behavior of glioblastoma multiforme cells

Glioblastoma multiforme (GBM) tumors are one of the most deadly forms of human cancer and despite improved treatments, median survival time for the majority of patients is a dismal 12-15 months. A hallmark of these aggressive tumors is their unique ability to diffusively infiltrate normal brain tissue. To understand this behavior and successfully target the mechanisms underlying tumor progression, it is crucial to develop robust experimental ex vivo disease models. This review discusses current two-dimensional (2D) experimental models, as well as animal-based models used to examine GBM cell migration, including their advantages and disadvantages. Recent attempts to develop three-dimensional (3D) tissue engineering-inspired models and their utility in unraveling the role of microenvironment on tumor cell behaviors are also highlighted. Further, the use of 3D models to bridge the gap between 2D and animal models is explored. Finally, the broad utility of such models in the context of brain cancer research is examined.

Associations between single-nucleotide polymorphisms in the PI3K-PTEN-AKT-mTOR pathway and increased risk of brain metastasis in patients with non-small cell lung cancer

PURPOSE

Non-small cell lung cancer (NSCLC) metastasizes fairly often to the brain, but identifying which patients will develop brain metastases is problematic. The phosphoinositide 3-kinase (PI3K)-AKT-mTOR signaling pathway is important in the control of cell growth, tumorigenesis, and cell invasion. We hypothesized that genotype variants in this pathway could predict brain metastasis in patients with NSCLC.

METHODS

We genotyped 16 single-nucleotide polymorphisms (SNP) in five core genes (PIK3CA, PTEN, AKT1, AKT2, and FRAP1) by using DNA from blood samples of 317 patients with NSCLC, and evaluated potential associations with the subsequent development of brain metastasis, the cumulative incidence of which was estimated with Kaplan-Meier analysis. Multivariate Cox regression analysis was used to analyze correlations between genotype variants and the occurrence of brain metastasis.

RESULTS

In analysis of individual SNPs, the GT/GG genotype of AKT1: rs2498804, CT/TT genotype of AKT1: rs2494732, and AG/AA genotype of PIK3CA: rs2699887 were associated with higher risk of brain metastasis at 24-month follow-up [respective HRs, 1.860, 95% confidence interval (CI) 1.199-2.885, P = 0.006; HR 1.902, 95% CI 1.259-2.875, P = 0.002; and HR 1.933, 95% CI 1.168-3.200, P = 0.010]. We further found that these SNPs had a cumulative effect on brain metastasis risk, with that risk being highest for patients carrying both of these unfavorable genotypes (P = 0.003).

CONCLUSIONS

Confirmation of our findings, the first to indicate that genetic variations in PI3K-AKT-mTOR can predict brain metastasis, in prospective studies would facilitate stratification of patients for brain metastasis prevention trials.

Breast metastases from oligodendroglioma: an unusual extraneural spread in two young women and a review of the literature

BACKGROUND

Extraneural dissemination of oligodendroglioma is rare. Cases of breast metastases have never been described in the literature.

CASE REPORTS

We report the first two cases of young women with initial diagnosis of anaplastic oligodendroglioma who experienced mammary gland metastases and a review of the literature.

RESULTS

Immunohistochemical analysis performed on material from both primary and metastatic sites did not allow to draw any conclusion on possible etiopathogenetic hypothesis. A review of literature yielded 35 cases of extracranial metastatic oligodendroglioma from 1989 to 2012.

CONCLUSION

Though rare, extracranial dissemination from oligodendroglioma may occur not only in long surviving heavily pre-treated patients. The review of literature and these two cases suggest that spread is primarily to bone and then from bone to other organs through hematogenous route mostly due to leptomeningeal or dura mater invasion. Chemotherapy regimens similar to those commonly used for non metastatic oligodendroglioma are recommended for patients with good performance status.

Leukemia-like onset of bone marrow metastasis from anaplastic oligodendroglioma after 17 years of dormancy: an autopsy case report

Extraneural metastases from primary brain tumors are extremely rare. We present an autopsy case that displayed a very late and unique pattern of metastasis from an anaplastic oligodendroglioma. The patient was a 74-year-old woman who was disease free for 17 years after resection of the primary oligodendroglioma. She was subsequently admitted to a hospital for heart failure where her bone marrow was found to be completely infiltrated with tumor cells, eventually resulting in disseminated intravascular coagulation. The onset was like leukemia, but the "blast-like" cells were different from leukemic cells, and the diagnosis was difficult until autopsy. After her death, a review of her past medical history and comprehensive analysis of her primary brain tumor and aspiration biopsy/autopsy bone marrow samples with glial immunohistochemical markers, fluorescence in situ hybridization examination, and immunohistochemical/sequencing analyses of mutant IDH1 revealed the accurate diagnosis. The metastatic tumor in her bone marrow was finally diagnosed as bone metastasis from the primary anaplastic oligodendroglioma. Although metastatic oligodendroglioma is very rare, it should be noted that this condition displays a propensity for bone and bone marrow and can present with features similar to those of leukemia after a long latency period.

Longitudinal MRI evaluation of intracranial development and vascular characteristics of breast cancer brain metastases in a mouse model

Longitudinal MRI was applied to monitor intracranial initiation and development of brain metastases and assess tumor vascular volume and permeability in a mouse model of breast cancer brain metastases. Using a 9.4T system, high resolution anatomic MRI and dynamic susceptibility contrast (DSC) perfusion MRI were acquired at different time points after an intracardiac injection of brain-tropic breast cancer MDA-MB231BR-EGFP cells. Three weeks post injection, multifocal brain metastases were first observed with hyperintensity on T₂-weighted images, but isointensity on T₁-weighted post contrast images, indicating that blood-tumor-barrier (BTB) at early stage of brain metastases was impermeable. Follow-up MRI revealed intracranial tumor growth and increased number of metastases that distributed throughout the whole brain. At the last scan on week 5, T₁-weighted post contrast images detected BTB disruption in 160 (34%) of a total of 464 brain metastases. Enhancement in some of the metastases was only seen in partial regions of the tumor, suggesting intratumoral heterogeneity of BTB disruption. DSC MRI measurements of relative cerebral blood volume (rCBV) showed that rCBV of brain metastases was significantly lower (mean  = 0.89±0.03) than that of contralateral normal brain (mean  = 1.00±0.03; p<0.005). Intriguingly, longitudinal measurements revealed that rCBV of individual metastases at early stage was similar to, but became significantly lower than that of contralateral normal brain with tumor growth (p<0.05). The rCBV data were concordant with histological analysis of microvascular density (MVD). Moreover, comprehensive analysis suggested no significant correlation among tumor size, rCBV and BTB permeability. In conclusion, longitudinal MRI provides non-invasive in vivo assessments of spatial and temporal development of brain metastases and their vascular volume and permeability. The characteristic rCBV of brain metastases may have a diagnostic value.

Probing the mechanical properties of brain cancer cells using a microfluidic cell squeezer device

Despite being invasive within surrounding brain tissues and the central nervous system, little is known about the mechanical properties of brain tumor cells in comparison with benign cells. Here, we present the first measurements of the peak pressure drop due to the passage of benign and cancerous brain cells through confined microchannels in a "microfluidic cell squeezer" device, as well as the elongation, speed, and entry time of the cells in confined channels. We find that cancerous and benign brain cells cannot be differentiated based on speeds or elongation. We have found that the entry time into a narrow constriction is a more sensitive indicator of the differences between malignant and healthy glial cells than pressure drops. Importantly, we also find that brain tumor cells take a longer time to squeeze through a constriction and migrate more slowly than benign cells in two dimensional wound healing assays. Based on these observations, we arrive at the surprising conclusion that the prevailing notion of extraneural cancer cells being more mechanically compliant than benign cells may not apply to brain cancer cells.

The role of brevican in glioma: promoting tumor cell motility in vitro and in vivo

BACKGROUND

Malignant glioma is a common primary tumor of the central nervous system. Brevican, an abundant extracellular matrix component in the adult brain, plays a critical role in the process of glioma. The mechanisms for the highly invasive behavior of gliomas are still poorly understood. The aim of this study was to examine whether brevican is a predictor of glioma and its roles in glioma cell motility.

METHODS

In this study, immunohistochemistry staining for brevican expression was performed in malignant gliomas and benign controls. We also explored the effects of brevican on cell adhesion and migration in brevican-overexpressed cells. Knockdown of brevican expression was achieved by stable transfection of U251 cells transduced with a construct encoding a short hairpin DNA directed against the brevican gene, which correspondingly, down-regulated the proliferation, invasion and spread of brevican-expressing cells. Moreover, the role of brevican in the growth and progression of glioma was demonstrated by in vivo studies.

RESULTS

Our results provide evidence for the molecular and cellular mechanisms that may underlie the motility-promoting role of brevican in the progression of glioma. The role of brevican as a target for immunotherapy might be taken into consideration in future studies.

CONCLUSIONS

This study suggests that expression of brevican is associated with glioma cell adhesion, motility and tumor growth, and also is related to glioma cell differentiation, therefore it may be a marker for malignance degree of glioma.

SNPs in the TGF-β signaling pathway are associated with increased risk of brain metastasis in patients with non-small-cell lung cancer

Purpose

Brain metastasis (BM) from non-small cell lung cancer (NSCLC) is relatively common, but identifying which patients will develop brain metastasis has been problematic. We hypothesized that genotype variants in the TGF-β signaling pathway could be a predictive biomarker of brain metastasis.

Patients and Methods

We genotyped 33 SNPs from 13 genes in the TGF-β signaling pathway and evaluated their associations with brain metastasis risk by using DNA from blood samples from 161 patients with NSCLC. Kaplan-Meier analysis was used to assess brain metastasis risk; Cox hazard analyses were used to evaluate the effects of various patient and disease characteristics on the risk of brain metastasis.

Results

The median age of the 116 men and 45 women in the study was 58 years; 62 (39%) had stage IIIB or IV disease. Within 24 months after initial diagnosis of lung cancer, brain metastasis was found in 60 patients (37%). Of these 60 patients, 16 had presented with BM at diagnosis. Multivariate analysis showed the GG genotype of SMAD6: rs12913975 and TT genotype of INHBC: rs4760259 to be associated with a significantly higher risk of brain metastasis at 24 months follow-up (hazard ratio [HR] 2.540, 95% confidence interval [CI] 1.204–5.359, P = 0.014; and HR 1.885, 95% CI 1.086–3.273, P = 0.024), compared with the GA or CT/CC genotypes, respectively. When we analyzed combined subgroups, these rates showed higher for those having both the GG genotype of SMAD6: rs12913975 and the TT genotype of INHBC: rs4760259 (HR 2.353, 95% CI 1.390–3.985, P = 0.001).

Conclusions

We found the GG genotype of SMAD6: rs12913975 and TT genotype of INHBC: rs4760259 to be associated with risk of brain metastasis in patients with NSCLC. This finding, if confirmed, can help to identify patients at high risk of brain metastasis.

Skeletal spread of an anaplastic astrocytoma (WHO grade III) and preservation of histopathological properties within metastases

BACKGROUND

The incidence of extraneural metastases of glioma is low. Metastases occur at different sites and, infrequently, as diffuse bone marrow infiltration. Direct contact of a glioma with extrameningeal tissues might be a reason for extraneural metastases. However, the role of haematogenous spread remains unclear.

METHODS

We report on a young patient who suffered from a left frontal anaplastic WHO grade III astrocytoma, which was treated with gross total resection and irradiation (60 Gy). No local relapse occurred during the following course, but a diffuse infiltration of the bone marrow was diagnosed 12 months after the initial diagnosis. The patient died 6 months later, as a result of hypercalcaemia and pancytopenia. The histopathological properties of the tumour and its bone metastases were analysed, as well as the mutations of the isocitrate dehydrogenase 1 gene (IDH1). To study the route of tumour dissemination, the peripheral blood of the patient was analysed for circulating tumour cells (CTCs).

RESULTS

This study describes a rare case of an extraneurally metastasised WHO grade III anaplastic astrocytoma. The occurrence of bone marrow infiltration coinciding with the finding of a stable intracranial tumour is a notably unusual situation. The properties of the primary tumour were maintained within the metastases in our patient. No CTCs were found in the peripheral blood at one random time point after the diagnosis of bone metastases.

CONCLUSIONS

Despite young patient age, a stable intracranial course with a single location and mutations in the IDH1 gene, the patient's overall survival was short at 18 months after diagnosis. This finding illustrates the therapeutic dilemma in patients with bone marrow involvement complicating the use of alkylating agents, such as temozolomide. Repeated and systematic blood sampling in a large cohort of patients is needed for the detection of CTCs in glioma patients with systemic tumour spread. Future studies investigating how intrinsic factors in glioma cell biology cause rare metastases in these tumours are needed.

Extraneural metastasis of glioblastoma multiforme presenting as an unusual neck mass

Glioblastoma multiforme (GBM) is the most aggressive intracranial tumor and it commonly spreads by direct extension and infiltration into the adjacent brain tissue and along the white matter tract. The metastatic spread of GBM outside of the central nervous system (CNS) is rare. The possible mechanisms of extraneural metastasis of the GBM have been suggested. They include the lymphatic spread, the venous invasion and the direct invasion through dura and bone. We experienced a 46-year-old man who had extraneural metastasis of the GBM on his left neck. The patient was treated with surgery for 5 times, radiotherapy and chemotherapy. He had survived 6 years since first diagnosed. Although the exact mechanism of the extraneural metastasis is not well understood, this present case shows the possibility of extraneural metastasis of the GBM, especially in patients with long survival.

Skin spread from an intracranial glioblastoma: case report and review of the literature

Extracranial metastases secondary to intracranial neoplasm are extremely rare. The incidence of extraneural metastases of brain tumours is estimated to be less than 0.4%. The authors report a case of postoperative intracranial glioblastoma spreading to the skin in an adult patient. In this case, the radiological images and surgical findings suggest that the potential dissemination mechanism is as a result of infiltration through the surgical wound site. The primary tumour-upon coming into contact with the dura and the skin-mimicked the characteristics of both tissues. This case supports the theory of risk of spread through the durotomy site, although this phenomenon is extremely rare. Both the specific pathogenic mechanisms as well as the ideal and effective management have not been established yet and require further investigation.