Stable glioma incidence and increased patient survival over the past two decades in Norway: a nationwide registry-based cohort study

BACKGROUND

Surveillance of incidence and survival of central nervous system tumors is essential to monitor disease burden and epidemiological changes, and to allocate health care resources. Here, we describe glioma incidence and survival trends by histopathology group, age, and sex in the Norwegian population.

MATERIAL AND METHODS

We included patients with a histologically verified glioma reported to the Cancer Registry of Norway from 2002 to 2021 (N = 7,048). Population size and expected mortality were obtained from Statistics Norway. Cases were followed from diagnosis until death, emigration, or 31 December 2022, whichever came first. We calculated age-standardized incidence rates (ASIR) per 100,000 person-years and age-standardized relative survival (RS).  Results: The ASIR for histologically verified gliomas was 7.4 (95% CI: 7.3-7.6) and was higher for males (8.8; 95% CI: 8.5-9.1) than females (6.1; 95% CI: 5.9-6.4). Overall incidence was stable over time. Glioblastoma was the most frequent tumor entity (ASIR = 4.2; 95% CI: 4.1-4.4). Overall, glioma patients had a 1-year RS of 63.6% (95% CI: 62.5-64.8%), and a 5-year RS of 32.8% (95% CI: 31.6-33.9%). Females had slightly better survival than males. For most entities, 1- and 5-year RS improved over time (5-year RS for all gliomas 29.0% (2006) and 33.1% (2021), p < 0.001). Across all tumor types, the RS declined with increasing age at diagnosis.

INTERPRETATION

The incidence of gliomas has been stable while patient survival has increased over the past 20 years in Norway. As gliomas represent a heterogeneous group of primary CNS tumors, regular reporting from cancer registries at the histopathology group level is important to monitor disease burden and allocate health care resources in a population.

Inhibition of extracellular vesicle-derived miR-146a-5p decreases progression of melanoma brain metastasis via Notch pathway dysregulation in astrocytes

Melanoma has the highest propensity of all cancers to metastasize to the brain with a large percentage of late-stage patients developing metastases in the central nervous system (CNS). It is well known that metastasis establishment, cell survival, and progression are affected by tumour-host cell interactions where changes in the host cellular compartments likely play an important role. In this context, miRNAs transferred by tumour derived extracellular vesicles (EVs) have previously been shown to create a favourable tumour microenvironment. Here, we show that miR-146a-5p is highly expressed in human melanoma brain metastasis (MBM) EVs, both in MBM cell lines as well as in biopsies, thereby modulating the brain metastatic niche. Mechanistically, miR-146a-5p was transferred to astrocytes via EV delivery and inhibited NUMB in the Notch signalling pathway. This resulted in activation of tumour-promoting cytokines (IL-6, IL-8, MCP-1 and CXCL1). Brain metastases were significantly reduced following miR-146a-5p knockdown. Corroborating these findings, miR-146a-5p inhibition led to a reduction of IL-6, IL-8, MCP-1 and CXCL1 in astrocytes. Following molecular docking analysis, deserpidine was identified as a functional miR-146a-5p inhibitor, both in vitro and in vivo. Our results highlight the pro-metastatic function of miR-146a-5p in EVs and identifies deserpidine for targeted adjuvant treatment.

Glioblastom hos voksne

Glioblastoma is the most common form of primary brain cancer in adults, and the disease has a serious prognosis. Although great progress has been made in molecular characteristics, no major breakthroughs in treatment have been achieved for many years. In this article we present a clinical review of current diagnostics and treatment, as well as the challenges and opportunities inherent in developing improved and more personalised treatment.

Surgical treatment and outcome of chronic subdural hematoma: a comparative study between Ethiopia and Norway

BACKGROUND

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. Here, we studied differences in demographics, treatment, and outcome for CSDH patients in low-income (Ethiopia) and high-income (Norway) countries and assessed potential outcome determinants.

METHODS

We included patients from Addis Ababa University Hospitals (AAUH) and Haukeland University Hospital (HUH) who had surgery for CSDH (2013-2017). Patients were included prospectively in Ethiopia and retrospectively in Norway.

RESULTS

We enrolled 314 patients from AAUH and 284 patients from HUH, with a median age of 60 and 75 years, respectively. Trauma history was more common in AAUH (72%) than in HUH patients (64.1%). More patients at HUH (45.1%) used anticoagulants/antiplatelets than at AAUH (3.2%). Comorbidities were more frequent in HUH (77.5%) than in AAUH patients (30.3%). Burr hole craniostomy under local anesthesia and postoperative drainage was the standard treatment in both countries. Postoperative CT scanning was more common at HUH (99.3%) than at AAUH (5.2%). Reoperations were more frequent at HUH (10.9%) than at AAUH (6.1%), and in both countries, mostly due to hematoma recurrence. Medical complications were more common at HUH (6.7%) than at AAUH (1.3%). The 1-year mortality rate at HUH was 7% and at AAUH 3.5%. At the end of follow-up (> 3 years), the Glasgow Outcome Scale Extended (GOSE) score was 8 in 82.9% of AAUH and 46.8% of HUH patients.

CONCLUSION

The surgical treatment was similar at AAUH and HUH. The poorer outcome in Norway could largely be explained by age, comorbidity, medication, and complication rates.

Effect of Spinal Cord Burst Stimulation vs Placebo Stimulation on Disability in Patients With Chronic Radicular Pain After Lumbar Spine Surgery: A Randomized Clinical Trial

IMPORTANCE

The use of spinal cord stimulation for chronic pain after lumbar spine surgery is increasing, yet rigorous evidence of its efficacy is lacking.

OBJECTIVE

To investigate the efficacy of spinal cord burst stimulation, which involves the placement of an implantable pulse generator connected to electrodes with leads that travel into the epidural space posterior to the spinal cord dorsal columns, in patients with chronic radiculopathy after surgery for degenerative lumbar spine disorders.

DESIGN, SETTING, AND PARTICIPANTS

This placebo-controlled, crossover, randomized clinical trial in 50 patients was conducted at St Olavs University Hospital in Norway, with study enrollment from September 5, 2018, through April 28, 2021. The date of final follow-up was May 20, 2022.

INTERVENTIONS

Patients underwent two 3-month periods with spinal cord burst stimulation and two 3-month periods with placebo stimulation in a randomized order. Burst stimulation consisted of closely spaced, high-frequency electrical stimuli delivered to the spinal cord. The stimulus consisted of a 40-Hz burst mode of constant-current stimuli with 4 spikes per burst and an amplitude corresponding to 50% to 70% of the paresthesia perception threshold.

MAIN OUTCOMES AND MEASURES

The primary outcome was difference in change from baseline in the self-reported Oswestry Disability Index (ODI; range, 0 points [no disability] to 100 points [maximum disability]; the minimal clinically important difference was 10 points) score between periods with burst stimulation and placebo stimulation. The secondary outcomes were leg and back pain, quality of life, physical activity levels, and adverse events.

RESULTS

Among 50 patients who were randomized (mean age, 52.2 [SD, 9.9] years; 27 [54%] were women), 47 (94%) had at least 1 follow-up ODI score and 42 (84%) completed all stimulation randomization periods and ODI measurements. The mean ODI score at baseline was 44.7 points and the mean changes in ODI score were -10.6 points for the burst stimulation periods and -9.3 points for the placebo stimulation periods, resulting in a mean between-group difference of -1.3 points (95% CI, -3.9 to 1.3 points; P = .32). None of the prespecified secondary outcomes showed a significant difference. Nine patients (18%) experienced adverse events, including 4 (8%) who required surgical revision of the implanted system.

CONCLUSIONS AND RELEVANCE

Among patients with chronic radicular pain after lumbar spine surgery, spinal cord burst stimulation, compared with placebo stimulation, after placement of a spinal cord stimulator resulted in no significant difference in the change from baseline in self-reported back pain-related disability.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03546738.

P10.13.B Repurposing neuroleptics to treat brain metastases: Clozapine as a novel therapy for melanoma brain metastases

Background

Around half of advanced melanoma patients develop brain metastases (BM) and survival is still measured in months. Current treatments, although increasingly effective, are not sufficient for this patient group, necessitating development of new therapeutic options. Drugs targeting BM specifically are a scarcity. However, utilizing drug repurposing, i.e. novel uses of drugs already approved for other medical conditions, may broaden available therapy options. Medications used to treat psychosis can penetrate an intact blood-brain barrier and it has been shown that patients with schizophrenia have lower incidences of certain cancer types than the rest of the population. Still, little is known on antitumor effects of neuroleptics on BM. We have preliminary data showing that the antipsychotic drug clozapine effectively inhibits growth of human melanoma brain metastasis (MBM) cell lines in vitro.

Material and Methods

We used the H1, H2, H3 and H10 MBM cell lines, as well as normal human astrocytes (NHA). Monolayer viability and IncuCyte studies were performed to determine IC50 doses. Cell migration was measured by a scratch wound assay. Apoptosis was studied by flow cytometry. Colony formation assays were performed using 2D clonogenic assays and 3D soft agar models. A protein array was used to find signaling proteins potentially affected by clozapine. The effect of clozapine on the normal brain was assessed, using a novel brain organoid model developed from fetal rat brains.

Results

A viability screening using 6 different neuroleptics showed that clozapine was most effective in inhibiting MBM cell viability, while NHA tolerated the same doses. MBM cells exhibited a dose-dependent inhibition of cell proliferation, migration, clonogenic formation and 3D growth. Flow cytometry demonstrated that apoptosis was a major mechanism of cytotoxicity. The protein array showed that CCL3, IL8 and VEGF were downstream targets of clozapine. These results are currently being confirmed by western blots. Doses significantly above MBM IC50 doses did not affect viability of brain organoids. Currently, a partnership with the Dept. of Chemistry (UiB) has been initiated to develop and test novel clozapine derivates, to find a more effective derivative with a larger therapeutic window and lesser side effects.

Conclusion

Clozapine shows promise as a novel agent for use in cancer therapy due its favorable tolerability, small molecular size and established clinical safety.

P12.09.B Extracellular vesicle derived-miR-146a increases melanoma brain metastasis progression via Notch signalling pathway dysregulation

Background

Melanoma has the highest tropism of any cancer to metastasize to the brain, and 40% of late-stage patients develop brain metastasis. Invasion, survival, and progression of tumors is dependent on the support of the surrounding microenvironment; therefore, modulation of neighboring cells is a key factor in metastasis. Extracellular vesicles (EVs) are important in cell-to-cell signalling, shuttling proteins, RNA and DNA to alter the surroundings into a favorable tumor microenvironment. Our aims were to investigate the role of melanoma brain metastasis (MBM) derived EVs in MBM development to find possible contributing mechanisms to cancer progression for eventual therapeutic targeting.

Material and Methods

MBM-EVs isolated via sequential ultracentrifugation were injected into mice as a pre-treatment prior to intracardial injection of MBM cells. EVs were co-cultured with normal human astrocytes (NHA) to investigate phenotypic changes. MiRNA sequencing was performed on EVs collected from MBM cells and compared to NHA and melanocytes to determine a candidate miRNA for targeting. In situ hybridization was utilized to evaluate the level of miRNA in clinical patient MBM samples. Functional in vivo validation was performed by injecting miRNA knockout MBM cells into mice. Sequencing of NHA in the presence or absence of target miRNA mimic was used to determine downstream targets.

Results

Mice primed with EVs had a significant increase in MBM tumor burden, compared to non-primed mice. Co-culture with MBM-EVs resulted in NHA activation in vitro, with increased proliferation, invasion, cytokine production, and upregulation of GFAP. MiR-146a was highly upregulated in MBM EVs, and miR-146a mimics activated NHA. Patient samples had a significant increase in miR-146a expression, compared to healthy brain controls. MiR-146a knockdown in MBM mice models reduced MBM burden and prolonged animal survival. Sequencing of NHA determined NUMB, an inhibitor of the Notch signalling pathway, as a target of miR-146a. Numb and other downstream Notch proteins expression was significantly altered in NHA in the presence of both MBM-EVs and miR-146a.

Conclusion

In conclusion, EVs are important regulators of MBM and establish tumor-supporting reactive astrocytes by delivery of miR-146a. MiR-146a alters Notch signalling in astrocytes via inhibition of the tumor suppressor gene NUMB. Elevated miR-146a levels in patients suggests a potential clinical intervention is possible via miR-146a targeting.

Is intracranial volume a risk factor for IDH-mutant low-grade glioma? A case-control study

Purpose

Risk of cancer has been associated with body or organ size in several studies. We sought to investigate the relationship between intracranial volume (ICV) (as a proxy for lifetime maximum brain size) and risk of IDH-mutant low-grade glioma.

Methods

In a multicenter case–control study based on population-based data, we included 154 patients with IDH-mutant WHO grade 2 glioma and 995 healthy controls. ICV in both groups was calculated from 3D MRI brain scans using an automated reverse brain mask method, and then compared using a binomial logistic regression model.

Results

We found a non-linear association between ICV and risk of glioma with increasing risk above and below a threshold of 1394 ml (p < 0.001). After adjusting for ICV, sex was not a risk factor for glioma.

Conclusion

Intracranial volume may be a risk factor for IDH-mutant low-grade glioma, but the relationship seems to be non-linear with increased risk both above and below a threshold in intracranial volume.

Prospective Study of Surgery for Traumatic Brain Injury in Addis Ababa, Ethiopia: Surgical Procedures, Complications, and Postoperative Outcomes

BACKGROUND

Traumatic brain injury (TBI) is an important cause of trauma-related mortality and morbidity in Ethiopia. There are significant resource limitations along the entire continuum of care, and little is known about the neurosurgical activity and patient outcomes.

METHODS

All surgically treated TBI patients at the 4 teaching hospitals in Addis Ababa, Ethiopia were prospectively registered from October 2012 to December 2016. Data registration included surgical procedures, complications, reoperations, discharge outcomes, and mortality.

RESULTS

A total of 1087 patients were included. The most common procedures were elevation of depressed skull fractures (49.5%) and craniotomies (47.9%). Epidural hematoma was the most frequent indication for a craniotomy (74.7%). Most (77.7%) patients were operated within 24 hours of admission. The median hospital stay for depressed skull fracture operations or craniotomies was 4 days. Decompressive craniectomy was only done in 10 patients. Postoperative complications were seen in 17% of patients, and only 3% were reoperated. Cerebrospinal fluid leak was the most common complication (7.9%). The overall mortality was 8.2%. Diagnosis, admission Glasgow Coma Scale (GCS) score, surgical procedure, and complications were significant predictors of discharge GCS score (P < 0.01). Age, admission GCS score, and length of hospital stay were significantly associated with mortality (P ≤ 0.005).

CONCLUSIONS

The injury panorama, surgical activity, and outcome are significantly influenced by patient selection due to deficits within both prehospital and hospital care. Still, the neurosurgical services benefit a large number of patients in the greater Addis region and are qualitatively comparable with reports from high-income countries.

Prospective Study of Surgery for Traumatic Brain Injury in Addis Ababa, Ethiopia: Trauma Causes, Injury Types, and Clinical Presentation

BACKGROUND

Traumatic brain injury (TBI) is a public health problem in Ethiopia. More knowledge about the epidemiology and neurosurgical management of TBI patients is needed to identify possible focus areas for quality improvement and preventive efforts.

METHODS

This prospective cross-sectional study (2012-2016) was performed at the 4 teaching hospitals in Addis Ababa, Ethiopia. All surgically treated TBI patients were included, and data on clinical presentation, injury types, and trauma causes were collected.

RESULTS

We included 1087 patients (mean age 29 years; 8.7% females; 17.1% <18 years old). Only 15.5% of TBIs were classified as severe (Glasgow Coma Scale score 3-8). Depressed skull fracture (44.9%) and epidural hematoma (39%) were the most frequent injuries. Very few patients had polytrauma (3.1%). Assault was the most common injury mechanism (69.9%) followed by road traffic accidents (15.8%) and falls (8.1%). More than 80% of patients came from within 200 km of the hospitals, but the median time to admission was 24 hours. Most assault victims (80.4%) were injured >50 km from the hospitals, whereas 46% of road traffic accident victims came from the urban area. Delayed admission was associated with higher Glasgow Coma Scale scores and nonsevere TBI (P < 0.01).

CONCLUSIONS

The injury panorama, delayed admission, and small number of operations performed for severe TBI are linked to a substantial patient selection bias both before and after hospital admission. Our results also suggest that there should be a geographical framework for tailored guidelines, preventive efforts, and development of prehospital and hospital services.

Improved Drug Delivery to Brain Metastases by Peptide-Mediated Permeabilization of the Blood-Brain Barrier

Patients with melanoma have a high risk of developing brain metastasis, which is associated with a dismal prognosis. During early stages of metastasis development, the blood-brain barrier (BBB) is likely intact, which inhibits sufficient drug delivery into the metastatic lesions. We investigated the ability of the peptide, K16ApoE, to permeabilize the BBB for improved treatment with targeted therapies preclinically. Dynamic contrast enhanced MRI (DCE-MRI) was carried out on NOD/SCID mice to study the therapeutic window of peptide-mediated BBB permeabilization. Further, both in vivo and in vitro assays were used to determine K16ApoE toxicity and to obtain mechanistic insight into its action on the BBB. The therapeutic impact of K16ApoE on metastases was evaluated combined with the mitogen-activated protein kinase pathway inhibitor dabrafenib, targeting BRAF mutated melanoma cells, which is otherwise known not to cross the intact BBB. Our results from the DCE-MRI experiments showed effective K16ApoE-mediated BBB permeabilization lasting for up to 1 hour. Mechanistic studies showed a dose-dependent effect of K16ApoE caused by induction of endocytosis. At concentrations above IC₅₀, the peptide additionally showed nonspecific disturbances on plasma membranes. Combined treatment with K16ApoE and dabrafenib reduced the brain metastatic burden in mice and increased animal survival, and PET/CT showed that the peptide also facilitated the delivery of compounds with molecular weights as large as 150 kDa into the brain. To conclude, we demonstrate a transient permeabilization of the BBB, caused by K16ApoE, that facilitates enhanced drug delivery into the brain. This improves the efficacy of drugs that otherwise do not cross the intact BBB.

THER-11. PEPTIDE-MEDIATED PERMEABILIZATION OF THE BLOOD-BRAIN BARRIER IMPROVES DRUG DELIVERY TO BRAIN METASTASIS

BACKGROUND: Melanoma patients have a high risk of developing brain metastases, which is associated with a poor prognosis. The blood-brain barrier (BBB) inhibits sufficient drug delivery into metastatic lesions. We investigated the ability of a synthetic peptide (K16ApoE) to permeabilize the BBB for more effective drug treatment. METHODS: DCE-MRI was performed to study the therapeutic window of BBB opening facilitated by K16ApoE. In vivoand in vitroassays were used to determine K16ApoE toxicity and also to obtain mechanistic insight into its action on the BBB. The therapeutic impact of K16ApoE on melanoma metastases was determined together with dabrafenib, which is otherwise known not to cross an intact BBB. RESULTS: DCE-MRI exhibited an effective K16ApoE-mediated BBB opening for up to 1h. Mechanistic studies displayed a dose-dependent effect of K16ApoE caused by induction of endocytosis. At higher concentrations, the peptide also showed unspecific disturbances on plasma membranes. Combined treatment with K16ApoE and dabrafenib reduced the brain metastatic burden in mice compared to dabrafenib. We also showed by PET/CT that the peptide facilitated the delivery of compounds up to 150 kDa into the brain. CONCLUSIONS: We demonstrate a transient opening of the BBB, caused by K16ApoE, that facilitates improved drug-delivery into the brain. This improves the efficacy of drugs that otherwise do not cross the intact BBB.

Inhibition of mitochondrial respiration prevents BRAF-mutant melanoma brain metastasis

Melanoma patients carry a high risk of developing brain metastases, and improvements in survival are still measured in weeks or months. Durable disease control within the brain is impeded by poor drug penetration across the blood-brain barrier, as well as intrinsic and acquired drug resistance. Augmented mitochondrial respiration is a key resistance mechanism in BRAF-mutant melanomas but, as we show in this study, this dependence on mitochondrial respiration may also be exploited therapeutically. We first used high-throughput pharmacogenomic profiling to identify potentially repurposable compounds against BRAF-mutant melanoma brain metastases. One of the compounds identified was β-sitosterol, a well-tolerated and brain-penetrable phytosterol. Here we show that β-sitosterol attenuates melanoma cell growth in vitro and also inhibits brain metastasis formation in vivo. Functional analyses indicated that the therapeutic potential of β-sitosterol was linked to mitochondrial interference. Mechanistically, β-sitosterol effectively reduced mitochondrial respiratory capacity, mediated by an inhibition of mitochondrial complex I. The net result of this action was increased oxidative stress that led to apoptosis. This effect was only seen in tumor cells, and not in normal cells. Large-scale analyses of human melanoma brain metastases indicated a significant role of mitochondrial complex I compared to brain metastases from other cancers. Finally, we observed completely abrogated BRAF inhibitor resistance when vemurafenib was combined with either β-sitosterol or a functional knockdown of mitochondrial complex I. In conclusion, based on its favorable tolerability, excellent brain bioavailability, and capacity to inhibit mitochondrial respiration, β-sitosterol represents a promising adjuvant to BRAF inhibitor therapy in patients with, or at risk for, melanoma brain metastases.

Thioridazine inhibits autophagy and sensitizes glioblastoma cells to temozolomide

Glioblastoma multiforme (GBM) has a poor prognosis with an overall survival of 14-15 months after surgery, radiation and chemotherapy using temozolomide (TMZ). A major problem is that the tumors acquire resistance to therapy. In an effort to improve the therapeutic efficacy of TMZ, we performed a genome-wide RNA interference (RNAi) synthetic lethality screen to establish a functional gene signature for TMZ sensitivity in human GBM cells. We then queried the Connectivity Map database to search for drugs that would induce corresponding changes in gene expression. By this approach we identified several potential pharmacological sensitizers to TMZ, where the most potent drug was the established antipsychotic agent Thioridazine, which significantly improved TMZ sensitivity while not demonstrating any significant toxicity alone. Mechanistically, we show that the specific chemosensitizing effect of Thioridazine is mediated by impairing autophagy, thereby preventing adaptive metabolic alterations associated with TMZ resistance. Moreover, we demonstrate that Thioridazine inhibits late-stage autophagy by impairing fusion between autophagosomes and lysosomes. Finally, Thioridazine in combination with TMZ significantly inhibits brain tumor growth in vivo, demonstrating the potential clinical benefits of compounds targeting the autophagy-lysosome pathway. Our study emphasizes the feasibility of exploiting drug repurposing for the design of novel therapeutic strategies for GBM.

Melanoma brain metastasis is independent of lactate dehydrogenase A expression

BACKGROUND

The key metabolic enzyme lactate dehydrogenase A (LDHA) is overexpressed in many cancers, and several preclinical studies have shown encouraging results of targeted inhibition. However, the mechanistic importance of LDHA in melanoma is largely unknown and hitherto unexplored in brain metastasis.

METHODS

We investigated the spatial, temporal, and functional features of LDHA expression in melanoma brain metastasis across multiple in vitro assays, in a robust and predictive animal model employing MRI and PET imaging, and in a unique cohort of 80 operated patients. We further assessed the genomic and proteomic landscapes of LDHA in different cancers, particularly melanomas.

RESULTS

LDHA expression was especially strong in early and small brain metastases in vivo and related to intratumoral hypoxia in late and large brain metastases in vivo and in patients. However, LDHA expression in human brain metastases was not associated with the number of tumors, BRAF(V600E) status, or survival. Moreover, LDHA depletion by small hairpin RNA interference did not affect cell proliferation or 3D tumorsphere growth in vitro or brain metastasis formation or survival in vivo. Integrated analyses of the genomic and proteomic landscapes of LDHA indicated that LDHA is present but not imperative for tumor progression within the CNS, or predictive of survival in melanoma patients.

CONCLUSIONS

In a large patient cohort and in a robust animal model, we show that although LDHA expression varies biphasically during melanoma brain metastasis formation, tumor progression and survival seem to be functionally independent of LDHA.

Abstract 4036: Drug repurposing to treat melanoma brain metastases

Despite recent therapeutic advances in the management of patients with metastatic melanoma, brain metastases remain an intractable problem. It has proven difficult to identify and target single genes or pathways critical to brain metastasis formation. In this work we set out to explore a more global and preventive treatment approach to melanoma brain metastases within an established xenograft model of human melanoma. Mice were injected intracardially under ultrasound guidance and followed for six weeks with whole-body BLI and brain MRI. Tumor-bearing brains, adrenals, ovaries, and femurs were harvested and enzymatically dissociated before three tumor cell samples from each organ were flow-sorted and subjected to RNA sequencing. We developed a combined workflow of several independent computational and statistical analyses based on differential expression, and defined a brain metastasis gene signature of 54 upregulated and 54 downregulated genes. We then queried the Connectivity Map database using our 108-gene signature for candidate drugs, i.e. drugs that induce an opposite gene expression profile in various cancer cell lines. Three of the top ten drugs, already in use for other clinical conditions, showed significant efficacy in monolayer proliferation assays and colony forming assays with two brain-tropic melanoma cell lines and one brain-tropic lung cancer cell line. To examine these results in vivo, we used a highly standardized and predictive model system with automated MRI-based quantification of nanoparticle-labeled cells in the mouse brain following intracardiac injection of human melanoma cells. Treatment was started shortly after verification of comparable tumor cell exposure in the mouse brains and animals were monitored with whole-body BLI and brain MRI. Preliminary results showed promising therapeutic effects with respect to brain metastatic burden and survival, as well as acceptable toxicity profiles. We are currently validating these results on a larger scale in vivo, in other models, as well as applying systems biology and network modeling approaches to explore the fundamental mechanisms of action. Together, our results demonstrate a previously unrecognized potential for drug repurposing in the treatment of patients at risk of developing melanoma brain metastases or with clinically occult micrometastatic disease. Finding new uses for old drugs can greatly expedite translation to clinical practice; thus, further investigations are warranted to determine the safety, tolerability, and efficacy of these therapies.

Citation Format: Terje Sundstrøm, Jobin K. Varughese, Francisco Azuaje, Kjell Petersen, Clifford G. Tepper, Elizabeth Ingham, Lisa Even, Sarah Tam, Kai Ove Skaftnesmo, Morten Lund-Johansen, Rolf Bjerkvig, Katherine W. Ferrara, Frits A. Thorsen. Drug repurposing to treat melanoma brain metastases. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4036. doi:10.1158/1538-7445.AM2014-4036

Prehospital use of cervical collars in trauma patients: a critical review

The cervical collar has been routinely used for trauma patients for more than 30 years and is a hallmark of state-of-the-art prehospital trauma care. However, the existing evidence for this practice is limited: Randomized, controlled trials are largely missing, and there are uncertain effects on mortality, neurological injury, and spinal stability. Even more concerning, there is a growing body of evidence and opinion against the use of collars. It has been argued that collars cause more harm than good, and that we should simply stop using them. In this critical review, we discuss the pros and cons of collar use in trauma patients and reflect on how we can move our clinical practice forward. Conclusively, we propose a safe, effective strategy for prehospital spinal immobilization that does not include routine use of collars.

Severe traumatic brain injury in Norway: impact of age on outcome

OBJECTIVE

The aim of this study was to investigate the influence of age on mortality and 3-month outcome in a Norwegian cohort of patients with severe traumatic brain injury (TBI).

METHODS

Norwegian residents ≥ 16 years of age who were admitted with a severe TBI to the country's 4 major trauma centres in 2009 and 2010 were included, as were adults (16- 64 years) and elderly patients (≥ 65 years).

RESULTS

Half of the adult subjects and 84% of the elderly subjects were injured by falls. One-third of the adults and half of the elderly subjects were admitted to a local hospital before being transported to a regional trauma hospital. Subdural haematomas were more frequent in the elderly subjects. One-quarter of adults and two-thirds of the elderly subjects died within 3 months. At 3 months, 41% of the adult survivors were still in-patients, mainly in rehabilitation units (92%). Of the surviving elderly subjects, 14% were in-patients and none were in rehabilitation units. There was no difference in functional level for survivors at the 3-month follow-up.

CONCLUSION

Old age is associated with fall-induced severe TBI and high mortality rates. Less intensive treatment strategies were applied to elderly patients in the present study despite high rates of haemorrhage. Few surviving elderly patients received rehabilitation at 3 months post-injury.

Multimodal imaging enables early detection and characterization of changes in tumor permeability of brain metastases

Our goal was to develop strategies to quantify the accumulation of model therapeutics in small brain metastases using multimodal imaging, in order to enhance the potential for successful treatment. Human melanoma cells were injected into the left cardiac ventricle of immunodeficient mice. Bioluminescent, MR and PET imaging were applied to evaluate the limits of detection and potential for contrast agent extravasation in small brain metastases. A pharmacokinetic model was applied to estimate vascular permeability. Bioluminescent imaging after injecting d-luciferin (molecular weight (MW) 320 D) suggested that tumor cell extravasation had already occurred at week 1, which was confirmed by histology. 7T T1w MRI at week 4 was able to detect non-leaky 100 μm sized lesions and leaky tumors with diameters down to 200 μm after contrast injection at week 5. PET imaging showed that (18)F-FLT (MW 244 Da) accumulated in the brain at week 4. Gadolinium-based MRI tracers (MW 559 Da and 2.066 kDa) extravasated after 5 weeks (tumor diameter 600 μm), and the lower MW agent cleared more rapidly from the tumor (mean apparent permeabilities 2.27 × 10(-5)cm/s versus 1.12 × 10(-5)cm/s). PET imaging further demonstrated tumor permeability to (64)Cu-BSA (MW 65.55 kDa) at week 6 (tumor diameter 700 μm). In conclusion, high field T1w MRI without contrast may improve the detection limit of small brain metastases, allowing for earlier diagnosis of patients, although the smallest lesions detected with T1w MRI were permeable only to d-luciferin and the amphipathic small molecule (18)F-FLT. Different-sized MR and PET contrast agents demonstrated the gradual increase in leakiness of the blood tumor barrier during metastatic progression, which could guide clinicians in choosing tailored treatment strategies.

Abstract 2699: Organ-specific signatures of melanoma metastasis

We have previously reported on a reproducible and predictive animal model that can be used to elucidate the enigmatic biology of melanoma metastasis, a key prerequisite for therapeutic advances. Here, we have used this model to investigate the molecular drivers responsible for metastasis formation in different organs, with a special emphasis on brain-specific features. A human melanoma brain metastasis cell line (H1) was developed in our laboratory, transduced with the genes for green fluorescent protein and luciferase, and injected into the left cardiac ventricle of seven immunodeficient mice. Whole-body bioluminescence imaging (BLI) and brain magnetic resonance imaging was performed weekly to follow the development of metastases. The animals invariably developed both intracranial and extracranial tumors. At about seven weeks, the animals were euthanized and organ involvement was examined in detail by ex vivo BLI. The brain, femurs, adrenals, and ovaries from five random animals were enzymatically dissociated using organ-tailored protocols. Sample yield was validated by fluorescence microscopy prior to fluorescence-activated cell sorting of tumor cells. Three tumor cell samples from the brain, femurs, adrenals, and ovaries of different mice were then analyzed using next-generation RNA-sequencing (NGS) technology. We also performed baseline NGS on the H1 cell line before injection. Taken together, bioinformatics analysis revealed unique molecular signatures of organ-specific metastasis, validating some previously reported metastasis drivers and introducing other genomic features critical to the detrimental momentum of metastatic melanoma.

Citation Format: Terje Sundstrøm, Lars Prestegarden, Clifford Tepper, Elizabeth Ingham, Lisa Even, Sarah Johnson, Kai Ove Skaftnesmo, Morten Lund-Johansen, Rolf Bjerkvig, Katherine Ferrara, Frits Thorsen. Organ-specific signatures of melanoma metastasis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2699. doi:10.1158/1538-7445.AM2013-2699

Abstract A39: Multimodal imaging of blood-brain barrier disruption during brain metastatic progression in a relevant experimental mouse model

Introduction: Efficient drug delivery to brain metastases is difficult due to an often intact blood-brain barrier (BBB) around smaller lesions, and very few therapeutic drugs penetrate an intact BBB. Relevant experimental brain metastatic models are needed to study biological mechanisms and therapeutic responses of early brain lesions in relation to the BBB. Previous studies injecting small molecules such as sodium fluorescein (MW 376D) have indicated that the BBB is disrupted in experimental brain metastasis larger than 0.25 mm (1). However, little is known regarding at which time point in experimental brain metastasis development the BBB is disrupted, and to what extent larger sized molecules at that time are able to penetrate tumor tissue. We addressed these issues by performing multimodal imaging studies, after injecting contrast agents of various sizes into an established melanoma brain metastasis model (2, 3).

Materials and Methods: All studies were approved by the UCD Animal Care and Use Committee. As in (3), we injected 5X105 human melanoma brain metastasis cells harboring the Luciferase and GFP genes, intracardially into 32 NOD/SCID mice. All animals were followed by bioluminescence imaging (BLI) weekly for 6 weeks. MRI (Bruker Biospec 70/30, RARE sequence, RARE factor=2, TE/TR/ST=9 ms/750 ms/1mm, FOV=2x2 cm, Matrix=256x256, NA=4) was performed at weeks 3, 4, 5 and 6 after tumor cell inoculation, before and after i.v. injections of either Gd-HPDO3A (Prohance, MW 559D, 0.5 μmol/g, 20 mice) or a newly synthetized Gadolinium contrast agent with 3 Gd(III) chelates, termed C3, (MW 2kD, 0.167 μmol/g, 5 mice). 64Cu-Albumin (MW 66.5kD) and 18F-FLT (MW 244D) was also injected i.v. prior to PET imaging at weeks 4 and 6.

Results and Discussion: BLI visualized tumor cell spread in all animal brains 15mins after injections, and a gradual increase in tumor burden between weeks 1 to 6. T1w MRI at week 3 did not show any tumors, however BLI confirmed presence of metastasis. MRI detected tumors at week 4, and the mean, total number of tumors increased from 26 tumors at week 4, to 89 tumors at week 6. There was an exponential increase in tumor burden from week 4 to 6. The number of leaky tumors also increased exponentially, with mean diameters increasing from around 600 μm to around 700 μm. The smallest leaky tumors detectable by MRI were ~200 μm (week 5). The number of non-leaky tumors peaked at 5 weeks, and their mean diameters increased from 260 μm to 450 μm. Metastatic tumor cell proliferation was shown by 18F-FLT, which accumulated in the animal brains at weeks 4 and 6. 64Cu-Albumin PET also showed leakage of albumin into the metastatic lesions at week 6.

Conclusions: Our study shows that T1w 7T MRI can detect leaky brain metastases down to ~200 μm in diameter. Molecules up to 2kD in size may penetrate brain tumor tissue early in tumor development. Our PET study indicates that larger molecules such as albumin may leak out of the metastatic lesions later in tumor development.

References

(1) Fidler IJ et al. Lancet Oncol 3:53-57, 2002.

(2) Sundstrøm T et al, Cancer Res 2012 (In Press).

(3) Wang J et al. Neuropathol Appl Neurobiol 37:189-205, 2011.

Citation Format: Frits Thorsen, Brett Fite, Lisa Mahakian, Victoria Harrison, Sarah Johnson, Elizabeth Ingham, Shengping Qin, Jai W. Seo, Thomas Meade, Terje Sundstrøm, Katherine W. Ferrara. Multimodal imaging of blood-brain barrier disruption during brain metastatic progression in a relevant experimental mouse model. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr A39.

Organisation of traumatic head injury management in the Nordic countries

OBJECTIVE

The aim of this study is to map and evaluate the available resources and the premises of traumatic head injury management in the Nordic countries, before the implementation of a Nordic adaption of the Brain Trauma Foundation guidelines for prehospital management.

METHODS

The study is a synthesis of two cross-sectional surveys. Questionnaires were used to collect data on the annual number of acute head injury operations, the infrastructure, the level of education, the use of trauma protocols and the management of traumatic head injury at Nordic hospitals.

RESULTS

The proportion of acute head injury operations performed outside a neurosurgical department was 0% in Denmark, 16% in Finland, 19% in Norway and 33% in Sweden. Eighty-four per cent of Nordic hospitals had written protocols for the assessment and treatment of trauma patients and 78% had regular training in trauma management; 67% had specific protocols for the treatment of traumatic head injury. Computed tomography (CT) was available in 93% of the hospitals, and 59% of the hospitals could link CT scans to the regional neurosurgical department.

CONCLUSIONS

Most Nordic hospitals are well prepared to manage patients with acute traumatic head injury. A substantial proportion of the operations are performed at local and central hospitals without neurosurgical expertise, despite an efficient pre and interhospital transport system. The Nordic adaption of the Brain Trauma Foundation guidelines recommends that this practice is terminated.

Five-year incidence of surgery for idiopathic normal pressure hydrocephalus in Norway

OBJECTIVES

We have previously determined the incidence and prevalence of idiopathic normal pressure hydrocephalus (iNPH) in the county of Vestfold in Norway. This study aimed at determining the incidence of surgeries for iNPH.

MATERIALS AND METHODS

Information about age, sex, operation year and operation type was collected retrospectively for all patients hospitalized from 2002 to 2006 with any diagnosis of iNPH and operated with insertion of a ventriculo-peritoneal or ventriculoatrial shunt system, or with endoscopic third ventriculostomy in any of Norway's five regional neurosurgical centers.

RESULTS

Two hundred fifty-two patients were operated during the 5-year period, making the total incidence 1.09/100,000/year. The yearly incidence ranged from a minimum of 0.84/100,000 in 2006 to a maximum of 1.47/100,000 in 2004. The incidence was highest in the age group 70-79 years. There were little regional differences regarding incidence, sex, and age and operation type.

CONCLUSIONS

The data suggest that too few patients are being offered surgical treatment for iNPH in Norway.

[Scandinavian guidelines for prehospital management of severe traumatic brain injury]

Head trauma is the cause the death for many young persons. The number of fatalities can be reduced through systematic management. Prevention of secondary brain injury combined with the fastest possible transport to a neurosurgical unit, have been shown to effectively reduce mortality and morbidity. Evidence-based guidelines already exist that focus on all steps in the process. In the present article members of the Scandinavian Neurotrauma Committee present recommendations on prehospital management of traumatic brain injury adapted to the infrastructure of the Nordic region.

[Scandinavian guidelines on the pre-hospital management of traumatic brain injury]

Head trauma causes the death of many young persons. The number of fatalities can be reduced through systematic management. Preventing secondary brain injury together with the fastest possible transport to a neurosurgical unit has been shown to be effective in reducing mortality and morbidity. Evidence-based guidelines already exist that focus on all steps in the management. This article, which was written by members of the Scandinavian Neurotrauma Committee, presents recommendations on the pre-hospital management of traumatic brain injury adapted to the infrastructure of Scandinavia.

Head injury mortality in the Nordic countries

Traumatic brain injury (TBI) is a major cause of morbidity and mortality in Western countries. Effective management planning for these patients requires knowledge of TBI epidemiology. The purpose of this study was to describe and analyze the development of TBI mortality in the Nordic countries during the period 1987-2001. Data on TBI deaths were retrieved from the national official statistical agencies according to specified diagnostic codes. We also collected data on the number of operations for acute TBI in the year 2000 from all Nordic hospitals admitting trauma patients. Finland had about twice as high a TBI mortality rate as the other countries. Similarly, the Finnish incidence of acute TBI operations was nearly twice that of the other countries. The median TBI death rate for Finland was 21.2 per 100,000 per year, and for Denmark, Norway, and Sweden 11.5, 10.4, and 9.5, respectively. There were more male than female deaths in all countries. The mortality rate from extracranial injuries was relatively equal between the countries. We observed a sizeable reduction in TBI mortality rates for all countries, except in Finland. Younger age groups had the most pronounced decrease in TBI mortality rates. The oldest age group had the least favorable development of TBI mortality rates, and the mean age of TBI casualties increased substantially during the study period. This study demonstrates considerable differences in and between the Nordic countries regarding TBI mortality. Preventive measures and implementation of regional guidelines are needed to assure a positive development in the future.

[Deaths from traumatic brain injury in the Nordic countries, 1987-2000]

BACKGROUND

Traumatic brain injury (TBI) is the major cause of death among young adults in western countries. In the context of a joint Nordic initiative regarding future management of patients with severe TBI, it was of interest to look into the magnitude of the problem and the most recent developments.

MATERIAL AND METHODS

We have conducted a survey of the epidemiological aspects of TBI deaths in Denmark, Finland, Norway and Sweden for the period 1987-2000. Data were retrieved from the official statistical agencies in the four countries. We have also collected data on the number of operations for acute TBI in the year 2000 from all Nordic hospitals admitting trauma patients.

RESULTS

There were almost twice as many deaths from TBI in Finland as in the other Nordic countries. The median mortality rate in Finland was 21.2 per 100,000 per year. The corresponding figures for Denmark were 12.8, Norway 10.5 and Sweden 9.8. Finland also had almost twice as many operations for acute TBI with 10.0 per 100,000 per year, versus 5.1 in Denmark, 4.8 in Norway and 5.7 in Sweden. The mortality rate was about three times higher among males than among females. All countries except Finland had a significant reduction in TBI deaths during the study period. The mortality rate from injuries other than TBI was more or less the same in all four countries.

INTERPRETATION

Our findings imply that there are twice as many severe TBIs and related deaths in Finland compared with the other Nordic countries.