Cardiovascular events and venous thromboembolism after primary malignant or non-malignant brain tumour diagnosis: a population matched cohort study in Wales (United Kingdom)

BACKGROUND

Elevated standardised mortality ratio of cardiovascular diseases (CVD) in patients with brain tumours may result from differences in the CVD incidences and cardiovascular risk factors. We compared the risk of CVD among patients with a primary malignant or non-malignant brain tumour to a matched general population cohort, accounting for other co-morbidities.

METHODS

Using data from the Secured Anonymised Information Linkage (SAIL) Databank in Wales (United Kingdom), we identified all adults aged ≥ 18 years in the primary care database with first diagnosis of malignant or non-malignant brain tumour identified in the cancer registry in 2000-2014 and a matched cohort (case-to-control ratio 1:5) by age, sex and primary care provider from the general population without any cancer diagnosis. Outcomes included fatal and non-fatal major vascular events (stroke, ischaemic heart disease, aortic and peripheral vascular diseases) and venous thromboembolism (VTE). We used multivariable Cox models adjusted for clinical risk factors to compare risks, stratified by tumour behaviour (malignant or non-malignant) and follow-up period.

RESULTS

There were 2869 and 3931 people diagnosed with malignant or non-malignant brain tumours, respectively, between 2000 and 2014 in Wales. They were matched to 33,785 controls. Within the first year of tumour diagnosis, malignant tumour was associated with a higher risk of VTE (hazard ratio [HR] 21.58, 95% confidence interval 16.12-28.88) and stroke (HR 3.32, 2.44-4.53). After the first year, the risks of VTE (HR 2.20, 1.52-3.18) and stroke (HR 1.45, 1.00-2.10) remained higher than controls. Patients with non-malignant tumours had higher risks of VTE (HR 3.72, 2.73-5.06), stroke (HR 4.06, 3.35-4.93) and aortic and peripheral arterial disease (HR 2.09, 1.26-3.48) within the first year of diagnosis compared with their controls.

CONCLUSIONS

The elevated CVD and VTE risks suggested risk reduction may be a strategy to improve life quality and survival in people with a brain tumour.

Cauda equina syndrome

Aims

Patients with cauda equina syndrome (CES) require emergency imaging and surgical decompression. The severity and type of symptoms may influence the timing of imaging and surgery, and help predict the patient's prognosis. Categories of CES attempt to group patients for management and prognostication purposes. We aimed in this study to assess the inter-rater reliability of dividing patients with CES into categories to assess whether they can be reliably applied in clinical practice and in research.

Methods

A literature review was undertaken to identify published descriptions of categories of CES. A total of 100 real anonymized clinical vignettes of patients diagnosed with CES from the Understanding Cauda Equina Syndrome (UCES) study were reviewed by consultant spinal surgeons, neurosurgical registrars, and medical students. All were provided with published category definitions and asked to decide whether each patient had 'suspected CES'; 'early CES'; 'incomplete CES'; or 'CES with urinary retention'. Inter-rater agreement was assessed for all categories, for all raters, and for each group of raters using Fleiss's kappa.

Results

Each of the 100 participants were rated by four medical students, five neurosurgical registrars, and four consultant spinal surgeons. No groups achieved reasonable inter-rater agreement for any of the categories. CES with retention versus all other categories had the highest inter-rater agreement (kappa 0.34 (95% confidence interval 0.27 to 0.31); minimal agreement). There was no improvement in inter-rater agreement with clinical experience. Across all categories, registrars agreed with each other most often (kappa 0.41), followed by medical students (kappa 0.39). Consultant spinal surgeons had the lowest inter-rater agreement (kappa 0.17).

Conclusion

Inter-rater agreement for categorizing CES is low among clinicians who regularly manage these patients. CES categories should be used with caution in clinical practice and research studies, as groups may be heterogenous and not comparable.

Variation in postoperative outcomes of patients with intracranial tumors: insights from a prospective international cohort study during the COVID-19 pandemic

BACKGROUND

This study assessed the international variation in surgical neuro-oncology practice and 30-day outcomes of patients who had surgery for an intracranial tumor during the COVID-19 pandemic.

METHODS

We prospectively included adults aged ≥18 years who underwent surgery for a malignant or benign intracranial tumor across 55 international hospitals from 26 countries. Each participating hospital recorded cases for 3 consecutive months from the start of the pandemic. We categorized patients' location by World Bank income groups (high [HIC], upper-middle [UMIC], and low- and lower-middle [LLMIC]). Main outcomes were a change from routine management, SARS-CoV-2 infection, and 30-day mortality. We used a Bayesian multilevel logistic regression stratified by hospitals and adjusted for key confounders to estimate the association between income groups and mortality.

RESULTS

Among 1016 patients, the number of patients in each income group was 765 (75.3%) in HIC, 142 (14.0%) in UMIC, and 109 (10.7%) in LLMIC. The management of 200 (19.8%) patients changed from usual care, most commonly delayed surgery. Within 30 days after surgery, 14 (1.4%) patients had a COVID-19 diagnosis and 39 (3.8%) patients died. In the multivariable model, LLMIC was associated with increased mortality (odds ratio 2.83, 95% credible interval 1.37-5.74) compared to HIC.

CONCLUSIONS

The first wave of the pandemic had a significant impact on surgical decision-making. While the incidence of SARS-CoV-2 infection within 30 days after surgery was low, there was a disparity in mortality between countries and this warrants further examination to identify any modifiable factors.

Prospective, multicentre study of screening, investigation and management of hyponatraemia after subarachnoid haemorrhage in the UK and Ireland

BACKGROUND

Hyponatraemia often occurs after subarachnoid haemorrhage (SAH). However, its clinical significance and optimal management are uncertain. We audited the screening, investigation and management of hyponatraemia after SAH.

METHODS

We prospectively identified consecutive patients with spontaneous SAH admitted to neurosurgical units in the United Kingdom or Ireland. We reviewed medical records daily from admission to discharge, 21 days or death and extracted all measurements of serum sodium to identify hyponatraemia (<135 mmol/L). Main outcomes were death/dependency at discharge or 21 days and admission duration >10 days. Associations of hyponatraemia with outcome were assessed using logistic regression with adjustment for predictors of outcome after SAH and admission duration. We assessed hyponatraemia-free survival using multivariable Cox regression.

RESULTS

175/407 (43%) patients admitted to 24 neurosurgical units developed hyponatraemia. 5976 serum sodium measurements were made. Serum osmolality, urine osmolality and urine sodium were measured in 30/166 (18%) hyponatraemic patients with complete data. The most frequently target daily fluid intake was >3 L and this did not differ during hyponatraemic or non-hyponatraemic episodes. 26% (n/N=42/164) patients with hyponatraemia received sodium supplementation. 133 (35%) patients were dead or dependent within the study period and 240 (68%) patients had hospital admission for over 10 days. In the multivariable analyses, hyponatraemia was associated with less dependency (adjusted OR (aOR)=0.35 (95% CI 0.17 to 0.69)) but longer admissions (aOR=3.2 (1.8 to 5.7)). World Federation of Neurosurgical Societies grade I-III, modified Fisher 2-4 and posterior circulation aneurysms were associated with greater hazards of hyponatraemia.

CONCLUSIONS

In this comprehensive multicentre prospective-adjusted analysis of patients with SAH, hyponatraemia was investigated inconsistently and, for most patients, was not associated with changes in management or clinical outcome. This work establishes a basis for the development of evidence-based SAH-specific guidance for targeted screening, investigation and management of high-risk patients to minimise the impact of hyponatraemia on admission duration and to improve consistency of patient care.

Reporting of PPI and the MCID in phase III/IV randomised controlled trials-a systematic review

BACKGROUND

Patient and public involvement (PPI) in clinical trial design contributes to ensuring the research objectives and outcome measures are relevant to patients. The minimal clinically important difference (MCID) in the primary outcome influences trial design and feasibility and should be predicated on PPI. We aimed to determine current practice of reporting PPI and the MCID in phase III/IV randomised controlled trials (RCTs).

METHODS

Following a search of Medline, Embase, and the Cochrane Central Register of Controlled Trials, we included primary publications of phase III/IV RCTs, in English, inclusive of any medical specialty or type of intervention, that reported a health-related outcome. We excluded protocols and secondary publications of RCTs. We extracted RCT characteristics, the use of PPI, and use of the MCID.

RESULTS

Between 1 July 2019 and 13 January 2020, 123 phase III/IV RCTs matched our eligibility criteria. Ninety percent evaluated a medical rather than surgical intervention. Oncology accounted for 21% of all included RCTs. Only 2.4% (n = 3) and 1.6% (n = 2) RCTs described PPI and the MCID respectively.

CONCLUSIONS

PPI and the MCID are poorly reported, so it is uncertain how these contributed to trial design. Improvement in the reporting of these items would increase confidence that results are relevant and clinically significant to patients, contributing to improving the overall trial design.

TRIAL REGISTRATION

Not registered.

Development of prediction models for one-year brain tumour survival using machine learning: a comparison of accuracy and interpretability

BACKGROUND AND OBJECTIVE

Prediction of survival in patients diagnosed with a brain tumour is challenging because of heterogeneous tumour behaviours and treatment response. Advances in machine learning have led to the development of clinical prognostic models, but due to the lack of model interpretability, integration into clinical practice is almost non-existent. In this retrospective study, we compare five classification models with varying degrees of interpretability for the prediction of brain tumour survival greater than one year following diagnosis.

METHODS

1028 patients aged ≥16 years with a brain tumour diagnosis between April 2012 and April 2020 were included in our study. Three intrinsically interpretable 'glass box' classifiers (Bayesian Rule Lists [BRL], Explainable Boosting Machine [EBM], and Logistic Regression [LR]), and two 'black box' classifiers (Random Forest [RF] and Support Vector Machine [SVM]) were trained on electronic patients records for the prediction of one-year survival. All models were evaluated using balanced accuracy (BAC), F1-score, sensitivity, specificity, and receiver operating characteristics. Black box model interpretability and misclassified predictions were quantified using SHapley Additive exPlanations (SHAP) values and model feature importance was evaluated by clinical experts.

RESULTS

The RF model achieved the highest BAC of 78.9%, closely followed by SVM (77.7%), LR (77.5%) and EBM (77.1%). Across all models, age, diagnosis (tumour type), functional features, and first treatment were top contributors to the prediction of one year survival. We used EBM and SHAP to explain model misclassifications and investigated the role of feature interactions in prognosis.

CONCLUSION

Interpretable models are a natural choice for the domain of predictive medicine. Intrinsically interpretable models, such as EBMs, may provide an advantage over traditional clinical assessment of brain tumour prognosis by weighting potential risk factors and their interactions that may be unknown to clinicians. An agreement between model predictions and clinical knowledge is essential for establishing trust in the models decision making process, as well as trust that the model will make accurate predictions when applied to new data.

A survey on clinical natural language processing in the United Kingdom from 2007 to 2022

Much of the knowledge and information needed for enabling high-quality clinical research is stored in free-text format. Natural language processing (NLP) has been used to extract information from these sources at scale for several decades. This paper aims to present a comprehensive review of clinical NLP for the past 15 years in the UK to identify the community, depict its evolution, analyse methodologies and applications, and identify the main barriers. We collect a dataset of clinical NLP projects (n = 94; £ = 41.97 m) funded by UK funders or the European Union's funding programmes. Additionally, we extract details on 9 funders, 137 organisations, 139 persons and 431 research papers. Networks are created from timestamped data interlinking all entities, and network analysis is subsequently applied to generate insights. 431 publications are identified as part of a literature review, of which 107 are eligible for final analysis. Results show, not surprisingly, clinical NLP in the UK has increased substantially in the last 15 years: the total budget in the period of 2019-2022 was 80 times that of 2007-2010. However, the effort is required to deepen areas such as disease (sub-)phenotyping and broaden application domains. There is also a need to improve links between academia and industry and enable deployments in real-world settings for the realisation of clinical NLP's great potential in care delivery. The major barriers include research and development access to hospital data, lack of capable computational resources in the right places, the scarcity of labelled data and barriers to sharing of pretrained models.

Impact of tumour characteristics and cancer treatment on cerebrovascular mortality after glioma diagnosis: Evidence from a population-based cancer registry

Objective

We aimed to examine brain tumour grade, a marker of biological aggressiveness, tumour size and cancer treatment are associated with cerebrovascular mortality among patients with malignant glioma, the most common and aggressive type of brain tumour.

Methods

We conducted a retrospective, observational cohort study using the US National Cancer Institute's state and regional population-based cancer registries. We identified adult patients with glioma in 2000 to 2018 (N=72,916). The primary outcome was death from cerebrovascular disease. Cox regression modelling was used to estimate the associations with cerebrovascular mortality of tumour grade, tumour size and treatment (surgery, radiotherapy, chemotherapy), calculating hazard ratios (HR) adjusted for these factors as well as for age, sex, race, marital status and calendar year.

Results

Higher grade (Grade IV vs Grade II: HR=2.47, 95% CI=1.69-3.61, p<0.001) and larger brain tumours (size 3 to <6 cm: HR=1.40, 95% CI=1.03 -1.89, p<0.05; size ≥ 6 cm: HR=1.47, 95% CI=1.02-2.13, p<0.05 compared to size < 3cm) were associated with increased cerebrovascular mortality. Cancer treatment was associated with decreased risk (surgery: HR= 0.60, p<0.001; chemotherapy: HR=0.42, p<0.001; radiation: HR= 0.69, p<0.05). However, among patents surviving five years or more from cancer diagnosis radiotherapy was associated with higher risk of cerebrovascular mortality (HR 2.73, 95% CI 1.49-4.99, p<0.01).

Conclusion

More aggressive tumour characteristics are associated with increased cerebrovascular mortality. Radiotherapy increased risk of cerebrovascular mortality five-year after cancer diagnosis. Further research is needed to better understand the long-term cardiovascular consequences of radiation therapy, and whether the consequent risk can be mitigated.

Extent of MGMT Promoter Methylation Modifies the Effect of Temozolomide on Overall Survival in Patients with Glioblastoma: A Regional Cohort Study

AIMS

MGMT methylation in glioblastoma predicts response to temozolomide but dichotomizing methylation status may mask the true prognostic value of quantitative MGMT methylation. This study evaluated whether extent of MGMT methylation interacts with the effect of temozolomide on overall survival.

METHOD

We included consecutive glioblastoma patients aged ≥16 years diagnosed (April 2012–May 2020) at a neuro-oncology center. All patients had quantitative MGMT methylation measured using pyrosequencing. Those with MGMT methylated tumors were stratified into high and low methylation groups based on a cut-off using Youden index on 2-year survival. Our accelerated failure time survival models included extent of MGMT methylation, age, postoperative Karnofsky performance score, extent of resection, temozolomide regimen, and radiotherapy.

RESULTS

There were 414 patients. Optimal cut-off point using Youden index was 25.9% MGMT methylation. The number of patients in the unmethylated, low and high methylation groups was 223 (53.9%), 81 (19.6%), and 110 (26.6%), respectively. In the adjusted model, high (hazard ratio [HR] 0.60, 95% confidence intervals [CI] 0.46– 0.79, P=0.005) and low (HR 0.67, 95% CI 0.50–0.89, P&lt;0.001) methylation groups had better survival compared to unmethylated group. There was no evidence for interaction between MGMT methylation and completed temozolomide regimen (interaction term for low methylation P=0.097; high methylation P=0.071). This suggests no strong effect of MGMT status on survival in patients completing temozolomide regimen. In patients not completing the temozolomide regimen, higher MGMT methylation predicted better survival (interaction terms P&lt;0.001).

CONCLUSION

Quantitative MGMT methylation may provide additional prognostic value. This is important when assessing clinical and research therapies.

Cardiovascular Events After Primary Malignant and Non-Malignant Brain Tumour Diagnosis: A Population Matched Cohort Study in Wales (United Kingdom)

AIMS

It is uncertain whether the elevated cardiovascular diseases (CVD) risks in patients with brain tumours is due to differences in the distribution of risk factors. We compared CVD risks among patients with a primary brain tumour to a matched general population cohort.

METHOD

Using data from the Secured Anonymised Information Linkage (SAIL) Databank in Wales, we identified adults aged ≥18 years with a diagnosis of brain tumour identified in the cancer registry between 2000-2014, and a matched cohort (case-to-control ratio 1:5) by age, sex and primary care provider from the general population. Outcomes included fatal and non-fatal major vascular events and venous thromboembolism (VTE). We used multivariable Cox models adjusted for clinical risk factors to compare risks.

RESULTS

There were 2,869 and 3,931 people diagnosed with malignant and non-malignant brain tumours, respectively, in Wales. They were matched to 33,785 controls. Within the first year of tumour diagnosis, malignant tumour was associated with VTE (hazard ratio [HR] 21.58, 95% confidence interval 16.12-28.88) and stroke (HR 3.32, 2.44-4.53). People with malignant tumour surviving one year had higher risks of VTE (HR 2.20, 1.52-3.18) and stroke (HR 1.45, 1.00-2.10) compared to their matched controls. Individuals with non-malignant tumours had higher risks of VTE (HR 3.72, 2.73-5.06), stroke (HR 4.06, 3.35-4.93) and aortic and peripheral arterial disease (HR 2.09, 1.26-3.48) within the first year of diagnosis compared with their controls.

CONCLUSION

The elevated risks of CVD suggest risk reduction a potential strategy to improve life quality and survival in people with malignant and non-malignant brain tumour.

Analytic Approaches to Clinical Validation of Results From Preclinical Models of Glioblastoma: A Systematic Review

AIMS

Analytic approaches to clinical validation of results from preclinical models are important in assessment of their relevance to human disease. This systematic review examined consistency in reporting of glioblastoma cohorts from The Cancer Genome Atlas (TCGA) or Chinese Glioma Genome Atlas (CGGA) and assessed whether studies included patient characteristics in their survival analyses.

METHOD

We searched Embase and Medline on 02Feb21 for studies using preclinical models of glioblastoma published after Jan2008 that used data from TCGA or CGGA to validate the association between ≥1 molecular marker and overall survival in adult patients with glioblastoma. Main data items included cohort characteristics, statistical significance of the survival analysis, and model covariates.

RESULTS

There were 58 eligible studies from 1,751 non-duplicate records investigating 126 individual molecular markers. In 14 studies published between 2017 and 2020 using TCGA RNA microarray data that should have the same cohort, the median number of patients was 464.5 (interquartile range 220.5–525). Of the 15 molecular markers that underwent more than one univariable or multivariable survival analyses, five had discrepancies between studies. Covariates used in the 17 studies that used multivariable survival analyses were age (76.5%), pre-operative functional status (35.3%), sex (29.4%) MGMT promoter methylation (29.4%), radiotherapy (23.5%), chemotherapy (17.6%), IDH mutation (17.6%) and extent of resection (5.9%).

CONCLUSION

Preclinical glioblastoma studies that used TCGA for validation did not provide sufficient information about their cohort selection and there were inconsistent results. Transparency in reporting and the use of analytic approaches that adjust for clinical variables can improve the reproducibility between studies.

Socioeconomic deprivation is associated with reduced efficacy of an insulin adjustment education program for people with type 1 diabetes

BACKGROUND

The Dose Adjustment for Normal Eating (DAFNE) course teaches insulin dose adjustment to match dietary carbohydrates and improve glycaemic control in participants with type 1 diabetes mellitus (T1DM). We investigated the association between socioeconomic deprivation and reduction in HbA1c as a marker of sustained glycaemic control, after attending DAFNE education.

METHODS

This retrospective observational study identified adults with T1DM who attended DAFNE training in NHS Lothian, South East Scotland. We extracted age, sex, postcode-based Scottish Index of Multiple Deprivation (SIMD) quintiles and annual HbA1c measurements available four years before and after course attendance. We calculated mean HbA1c before (baseline) and after attendance at DAFNE, across four annual measurements. Change in mean HbA1c (mmol/mol) was categorised into three groups: decrease (≥ - 2.5), no change (<±2.5), increase (≥ + 2.5). We used multivariable ordinal logistic regression, with baseline mean HbA1c as a covariate, to investigate the association of SIMD quintile with reduction in mean HbA1c.

RESULTS

335 participants were included. Age and sex distribution were similar across SIMD quintiles (Mean age = 45, range 21-91, 59% women). Lower SIMD quintiles (greater deprivation) had higher baseline mean HbA1c (SIMD 1: 76.0, SIMD 5: 69.0). Higher SIMD quintiles (lower deprivation) were associated with lower odds of no change/increase in mean HbA1c (SIMD 5, odds ratio = 0.25, 95% confidence interval 0.10, 0.58, p = 0.001, multivariable analysis).

CONCLUSION

Socioeconomic deprivation was associated with higher baseline mean HbA1c and lower reduction in HbA1c following DAFNE education. Future research could explore causes and how best to support participants from deprived areas.

PREVIOUS SUBMISSIONS

This work has not been previously submitted to a journal. This work was presented as a poster at The ABCD Conference 2021 and the abstract (of no more than 300 words) from the meeting has been published: Innes CWD, Henshall DE, Wilson B, Poon M, Morley SD, Ritchie SA. Socioeconomic deprivation is associated with reduced efficacy of an insulin adjustment education programme for people with type 1 diabetes. Br J Diabetes. 2021; 21: 293-296.

Temozolomide Sensitivity of Malignant Glioma Cell Lines – A Systematic Review Assessing Consistencies Between In Vitro Studies

AIMS

Malignant glioma cell line models are integral to pre-clinical testing of novel potential therapies. Accurate prediction of likely efficacy in the clinic requires that these models are reliable and consistent. We assessed this by examining the reporting of experimental conditions and sensitivity to temozolomide in glioma cells lines.

METHOD

We searched Medline and Embase (Jan 1994-Jan 2021) for studies evaluating the effect of temozolomide monotherapy on cell viability of at least one malignant glioma cell line. Key data items included type of cell lines, temozolomide exposure duration in hours (hr), and cell viability measure (IC50).

RESULTS

We included 212 studies from 2789 non-duplicate records that reported 248 distinct cell lines. The commonest cell line was U87 (60.4%). Only 10.4% studies used a patient-derived cell line. The proportion of studies not reporting each experimental condition ranged from 8.0–27.4%, including base medium (8.0%), serum supplementation (9.9%) and number of replicates (27.4%). In studies reporting IC50, the median value for U87 at 24 h, 48 h and 72 h was 123.9 μM (IQR 75.3–277.7 μM), 223.1 μM (IQR 92.0–590.1 μM) and 230.0 μM (IQR 34.1–650.0 μM), respectively. The median IC50 at 72 h for patient-derived cell lines was 220 μM (IQR 81.1–800.0 μM).

CONCLUSION

Temozolomide sensitivity reported in comparable studies was not consistent between or within malignant glioma cell lines. Drug discovery science performed on these models cannot reliably inform clinical translation. A consensus model of reporting can maximise reproducibility and consistency among in vitro studies.

Imaging timing after glioblastoma surgery (INTERVAL-GB): protocol for a UK and Ireland, multicentre retrospective cohort study

INTRODUCTION

Glioblastoma is the most common malignant primary brain tumour with a median overall survival of 12-15 months (range 6-17 months), even with maximal treatment involving debulking neurosurgery and adjuvant concomitant chemoradiotherapy. The use of postoperative imaging to detect progression is of high importance to clinicians and patients, but currently, the optimal follow-up schedule is yet to be defined. It is also unclear how adhering to National Institute for Health and Care Excellence (NICE) guidelines-which are based on general consensus rather than evidence-affects patient outcomes such as progression-free and overall survival. The primary aim of this study is to assess MRI monitoring practice after surgery for glioblastoma, and to evaluate its association with patient outcomes.

METHODS AND ANALYSIS

ImagiNg Timing aftER surgery for glioblastoma: an eVALuation of practice in Great Britain and Ireland is a retrospective multicentre study that will include 450 patients with an operated glioblastoma, treated with any adjuvant therapy regimen in the UK and Ireland. Adult patients ≥18 years diagnosed with glioblastoma and undergoing surgery between 1 August 2018 and 1 February 2019 will be included. Clinical and radiological scanning data will be collected until the date of death or date of last known follow-up. Anonymised data will be uploaded to an online Castor database. Adherence to NICE guidelines and the effect of being concordant with NICE guidelines will be identified using descriptive statistics and Kaplan-Meier survival analysis.

ETHICS AND DISSEMINATION

Each participating centre is required to gain local institutional approval for data collection and sharing. Formal ethical approval is not required since this is a service evaluation. Results of the study will be reported through peer-reviewed presentations and articles, and will be disseminated to participating centres, patients and the public.

OS07.2.A Evaluation of Intraoperative Surgical Adjuncts and Resection of Glioblastoma (ELISAR GB): A UK and Ireland multicentre, prospective observational cohort study

Background

Despite operative and adjuvant therapies, glioblastoma remains incurable, with the extent of resection being one of few treatments that can improve survival. To improve resection, operative adjuncts are used, with neuronavigation and 5-aminolevulinic acid (5-ALA) recommended as a standard of care in those aimed for maximal safe resection. Despite the standards, meta-analysis concluded that the impact of 5-ALA on the extent of surgical resection is of low quality due to bias in reporting tumour location and additional image guidance used, factors impacting on extent of resection as well as short-term neurological outcomes being uncertain. Therefore we aimed to evaluate the availability and use of 5-ALA and other adjuncts and compare surgical outcomes of 5-ALA-guided versus non-5-ALA-guided resections.

Material and Methods

A multicenter prospective observational cohort study was conducted across 27 out of 31 available centres in the UK and Ireland from 6 January until 19 March 2020. Inclusion criteria included adults with first diagnosis, supratentorial glioblastoma undergoing resection. Primary outcomes included: i) the availability and use of surgical adjuncts and ii) complete resection of enhancing tissue (CRET). Secondary outcomes included adverse events, new onset of postoperative neurological deficit and post-operative neurological function. Descriptive and inferential statistics were used for analysis with a p-value &lt;0.05 deemed significant.

Results

232 consecutive cases were identified. 142/232 cases were aimed for maximal safe resection subsequently divided into 5-ALA-guided (n=92) versus non-5-ALA-guided (n=50) resections. 5-ALA and neuronavigation were available across all centres. Neuronavigation and 5-ALA were used in 91% (n=129/142) and 65% (n=92/142) of cases aimed for maximal safe resection whereas 83% (n=75/90) and 49% (n=44/90) for debulk surgery. 35 unique combinations of surgical adjuncts were used in 232 operations. 5-ALA-guided resection yielded a higher percentage of CRET than without (55% versus 28%, p &lt; 0.01). The two groups showed no difference in adverse events (p=0.98), new onset of neurological deficit (p=0.88) nor neurological function (p=0.7). A logistic regression analysis showed that 5-ALA was an important predictor of CRET regardless of additional adjuncts used (OR 2.4, CI 0.96-5.97, P = 0.05), tumour location and molecular characterisation (OR 3.48, CI 1.61-7.51, P &lt;0.01).

Conclusion

Firstly, we showed that 5-ALA is not always used for glioblastoma aimed for CRET. Secondly, we report a great heterogeneity of adjuncts used for resection, possibly explained by a lack of high-quality evidence and surgeon training. Thirdly we demonstrate that 5-ALA-guided resection leads to higher percentage of CRET regardless of other adjuncts used, tumour location and molecular characterisation.

Utility of 5-ALA for resection of CNS tumours other than high-grade gliomas: a protocol for a systematic review

INTRODUCTION

5-aminolevulinic acid (5-ALA) is a proagent developed for fluorescent-guided surgery for high-grade glioma patients associated with a significant increase in resection conferring survival. 5-ALA was shown to penetrate the blood-brain barrier accumulating in malignant glioma cells with high selectivity, sensitivity and positive predictive value. However, those have yet to be explored aiding diagnosis for tumours of the central nervous system (CNS) other than high-grade gliomas (HGG). No up-to-date systematic review exists reporting the major surgical outcomes and diagnostic accuracy. We sought to conduct a systematic review of the literature summarising surgical outcomes, evaluate the quality of diagnostic accuracy reported in the literature and qualitatively assess the evidence to inform future studies.

METHODS AND ANALYSIS

We will search electronic databases (Medline, Embase) with subsequent interrogation of references lists of articles reporting the use of 5-ALA for brain tumours other than high-grade glioma adult patients, which also report the extent of resection and/or survival. Prospective and retrospective cohort and case-control studies with more than five patients will be included. Two independent reviewers will screen the abstracts and full articles, with a third reviewer resolving any conflicts. The data will be extracted in a standardised template and outcomes will be reported using descriptive statists. The quality of non-randomised studies will be appraised.

ETHICS AND DISSEMINATION

The study will summarise the available evidence on the effect of the clinical utility of 5-ALA in achieving resection and improving survival and its diagnostic accuracy for tumours of the CNS other than HGG. The data will be presented nationally and internationally and the manuscript will be published in a peer-reviewed journal. No ethical approvals were needed. The aim is to inform prospective studies minimising reporting bias allowing for more reliable, reproducible and generalisable results. The study has been registered in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.PROSPERO registration numberCRD42021260542.

The Neurology and Neurosurgery Interest Group (NANSIG)-ten years of cultivating interest in clinical neurosciences

Collaboration and successful teamworking are important components of clinical practise, and these skills should be cultivated early in medical school. The breadth of current medical school curricula means that students often have limited exposure to clinical neurosciences. Since its inception in 2009, the Neurology and Neurosurgery Interest Group (NANSIG) has become a national (UK and Republic of Ireland) example of student and junior doctor synergistic collaboration to deliver educational materials, research, conferences, seminars and workshops, as well as advocating for diversity in this field. Recently, it has expanded to incorporate an international audience and cater for a larger group of young medical professionals. The organisation has overcome numerous challenges and is constantly innovating new approaches to harness the necessary knowledge, skills and network to succeed in a career in neurosciences, neurology and neurosurgery. This article summarises the initiatives undertaken by the group over its first 10 years of existence and its organisational structure, as well as its future plans.

Investigation and management of serum sodium after subarachnoid haemorrhage (SaSH): a survey of practice in the United Kingdom and Republic of Ireland

BACKGROUND

Hyponatraemia is a common complication of aneurysmal subarachnoid haemorrhage (SAH). We aimed to determine current neurosurgical practice for the identification, investigation and management of hyponatraemia after SAH.

METHODS

An online questionnaire was completed by UK and Irish neurosurgical trainees and consultant collaborators in the Sodium after Subarachnoid Haemorrhage (SaSH) audit.

RESULTS

Between August 2019 and June 2020, 43 responses were received from 31 of 32 UK and Ireland adult neurosurgical units (NSUs). All units reported routine measurement of serum sodium either daily or every other day. Most NSUs reported routine investigation of hyponatraemia after SAH with paired serum and urinary osmolalities (94%), urinary sodium (84%), daily fluid balance (84%), but few measured glucose (19%), morning cortisol (13%), or performed a short Synacthen test (3%). Management of hyponatraemia was variable, with units reporting use of oral sodium supplementation (77%), fluid restriction (58%), hypertonic saline (55%), and fludrocortisone (19%).

CONCLUSIONS

Reported assessment of serum sodium after SAH was consistent between units, whereas management of hyponatraemia varied. This may reflect the lack of a specific evidence-base to inform practice.

Temozolomide sensitivity of malignant glioma cell lines - a systematic review assessing consistencies between in vitro studies

BACKGROUND

Malignant glioma cell line models are integral to pre-clinical testing of novel potential therapies. Accurate prediction of likely efficacy in the clinic requires that these models are reliable and consistent. We assessed this by examining the reporting of experimental conditions and sensitivity to temozolomide in glioma cells lines.

METHODS

We searched Medline and Embase (Jan 1994-Jan 2021) for studies evaluating the effect of temozolomide monotherapy on cell viability of at least one malignant glioma cell line. Key data items included type of cell lines, temozolomide exposure duration in hours (hr), and cell viability measure (IC50).

RESULTS

We included 212 studies from 2789 non-duplicate records that reported 248 distinct cell lines. The commonest cell line was U87 (60.4%). Only 10.4% studies used a patient-derived cell line. The proportion of studies not reporting each experimental condition ranged from 8.0-27.4%, including base medium (8.0%), serum supplementation (9.9%) and number of replicates (27.4%). In studies reporting IC50, the median value for U87 at 24 h, 48 h and 72 h was 123.9 μM (IQR 75.3-277.7 μM), 223.1 μM (IQR 92.0-590.1 μM) and 230.0 μM (IQR 34.1-650.0 μM), respectively. The median IC50 at 72 h for patient-derived cell lines was 220 μM (IQR 81.1-800.0 μM).

CONCLUSION

Temozolomide sensitivity reported in comparable studies was not consistent between or within malignant glioma cell lines. Drug discovery science performed on these models cannot reliably inform clinical translation. A consensus model of reporting can maximise reproducibility and consistency among in vitro studies.

Differential cerebrovascular risks in glioblastoma and meningioma patients: a population-based matched cohort study in Wales (United Kingdom)

Aims

There is limited evidence on cerebrovascular risks in glioblastoma and meningioma patients. We aimed to compare cerebrovascular risks of these patients with the general population.

Method

We used population-based routine healthcare and administrative data linkage in this matched cohort study. Cases were adult glioblastoma and meningioma patients diagnosed in Wales 2000-2014 identified in the cancer registry. Controls from cancer-free general population were matched to cases (5:1 ratio) on age (±5 years), sex and GP practice. Factors included in multivariable models were age, sex, index of multiple deprivation, hypertension, diabetes, high cholesterol, history of cardiovascular disease, and medications for cardiovascular diseases. Outcomes were fatal and non-fatal haemorrhagic and ischaemic stroke. We used flexible parametric models adjusting for confounders to calculate the hazard ratios (HR).

Results

Final analytic population was 16,921 participants, of which 1,340 had glioblastoma and 1,498 had meningioma. The median follow-up time was 0.5 year for glioblastoma patients, 4.9 years for meningioma patients, and 6.6 years for controls. The number of haemorrhage and ischaemic stroke was 154 and 374 in the glioblastoma matched cohort, respectively, and 180 and 569 in the meningioma matched cohort, respectively. The adjusted HRs for haemorrhagic and ischaemic stroke were 3.74 (95%CI 1.87-6.57) and 5.62 (95%CI 2.56-10.42) in glioblastoma patients, respectively, and were 2.42 (95%CI 1.58-3.52) and 1.86 (95%CI 1.54-2.23) in meningioma patients compared with their controls.

Conclusion

Glioblastoma and meningioma patients had higher cerebrovascular risks; these risks were even higher for glioblastoma patients. Further assessment of these potentially modifiable risks may improve survivorship.

The reporting quality of natural language processing studies: systematic review of studies of radiology reports

BACKGROUND

Automated language analysis of radiology reports using natural language processing (NLP) can provide valuable information on patients' health and disease. With its rapid development, NLP studies should have transparent methodology to allow comparison of approaches and reproducibility. This systematic review aims to summarise the characteristics and reporting quality of studies applying NLP to radiology reports.

METHODS

We searched Google Scholar for studies published in English that applied NLP to radiology reports of any imaging modality between January 2015 and October 2019. At least two reviewers independently performed screening and completed data extraction. We specified 15 criteria relating to data source, datasets, ground truth, outcomes, and reproducibility for quality assessment. The primary NLP performance measures were precision, recall and F1 score.

RESULTS

Of the 4,836 records retrieved, we included 164 studies that used NLP on radiology reports. The commonest clinical applications of NLP were disease information or classification (28%) and diagnostic surveillance (27.4%). Most studies used English radiology reports (86%). Reports from mixed imaging modalities were used in 28% of the studies. Oncology (24%) was the most frequent disease area. Most studies had dataset size > 200 (85.4%) but the proportion of studies that described their annotated, training, validation, and test set were 67.1%, 63.4%, 45.7%, and 67.7% respectively. About half of the studies reported precision (48.8%) and recall (53.7%). Few studies reported external validation performed (10.8%), data availability (8.5%) and code availability (9.1%). There was no pattern of performance associated with the overall reporting quality.

CONCLUSIONS

There is a range of potential clinical applications for NLP of radiology reports in health services and research. However, we found suboptimal reporting quality that precludes comparison, reproducibility, and replication. Our results support the need for development of reporting standards specific to clinical NLP studies.

P13.04 Survival analyses for determining clinical relevance of molecular markers in translational glioblastoma research - a systematic review

BACKGROUND

Pre-clinical glioblastoma studies can assess the relevance of their findings to patient survival using integrated clinical and genomic data. Validity of univariable analyses requires an assumption that molecular markers are randomly distributed across patient characteristics to mitigate the confounding effects of clinical variables. Multivariable survival analyses adjusting for clinical variables do not change the association if this assumption holds. We aimed to assess this by summarising the types of survival analyses and their results in translational glioblastoma research.

MATERIAL AND METHODS

We systematically searched Medline and Embase Jan 2008 to Feb 2021 for glioblastoma cell line or animal studies validating their molecular markers in The Cancer Genome Atlas (TCGA) or the Chinese Glioma Genome Atlas (CGGA) using survival analyses. Studies that exclusively used genomic data without laboratory findings were excluded. Two reviewers independently assessed study eligibility and extracted data. Data items included patient inclusion criteria, characteristics of survival analyses, and whether molecular markers had statistically significant association with overall survival.

RESULTS

Of 1,047 potentially eligible studies, we included 59 pre-clinical glioblastoma studies that tested the association between their molecular markers and survival using TCGA or CGGA data. All studies used TCGA data and 2 also used CGGA data. Sixteen (27%) studies specified their patient inclusion criteria from TCGA for survival analysis. Eight studies exclusively investigated sets of molecular markers, leaving 51 studies reporting 126 molecular markers. Eighteen (31%) studies used multivariable survival analysis in addition to univariable analyses. All molecular markers underwent univariable analyses, of which 12 (10%) molecular markers had additional multivariable survival analyses. In the 13 multivariable analyses on 12 molecular markers, four (31%) markers were associated with survival in the univariable analyses but not in the multivariable analyses.

CONCLUSION

Most pre-clinical studies used univariable survival analyses alone in public genomic repositories to assess the relevance of their results to patient survival. Our findings demonstrated that multivariable analyses are needed to account for confounding effects of clinical variables. Using relevant components from reporting guidelines for observational studies can improve the transparency and quality of translational studies.

P13.09 Inconsistent effect of temozolomide exposure on cell viability in glioblastoma cell line models - a systematic review

BACKGROUND

The alkylating agent temozolomide is part of standard care for patients with glioblastoma. Potential novel therapeutic agents are often first evaluated against temozolomide in glioblastoma cell line models. Despite the importance of this step in compound development, there is no standard concentration or exposure duration of temozolomide in laboratory research, and consistency in the effect of temozolomide on glioblastoma cell lines has not been assessed. This systematic review aimed to summarise the concentration and exposure duration of temozolomide and its effect on cell viability in studies using glioblastoma cell lines.

MATERIAL AND METHODS

We searched Medline and Embase Jan 1994 - Feb 2021 for studies that used at least one glioblastoma cell line and reported a measure of cell viability associated with temozolomide exposure. Studies were excluded if they used modified cell lines or did not report a cell viability measure associated with temozolomide as monotherapy. One reviewer screened all records and two reviewers assessed potentially eligible studies for inclusion. The main data items included the cell lines used, the concentration and exposure duration to temozolomide, and cell viability measures. We summarised findings using descriptive statistics.

RESULTS

Of 1,533 potentially eligible studies we included 213 studies reporting 209 different cell lines. The most common cell lines were U87, U251 and T98G, used in 61%, 41%, and 27% of studies, respectively. Twenty-five (12%) studies used patient-derived cell lines. The concentration of temozolomide used ranged from 0 to 8000μM. The temozolomide exposure duration ranged from &lt;24 hours to &gt;96 hours, with 29% studies using 72 hours. The most common cell viability measure was half maximal inhibitory concentration (IC50), which was reported in 183 (86%) studies. The median IC50 in 32 studies using the U87 cell line was 180μM (interquartile range [IQR]: 52–254μM) at 48-hour temozolomide exposure and 202μM (IQR 52–518μM) at 72-hour exposure. The median IC50 in 31 studies using U251 cell line was 84μM (IQR: 34–324μM) at 48-hour exposure and 102μM (IQR: 35–358μM) at 72-hour exposure.

CONCLUSION

Experimental setup of temozolomide and its effect on cell viability vary widely between studies using similar glioblastoma cell lines. This inconsistency of response to temozolomide questions reproducibility and the translational value of study findings.

Risks of recurrent stroke and all serious vascular events after spontaneous intracerebral haemorrhage: pooled analyses of two population-based studies

BACKGROUND

Patients with stroke due to spontaneous (non-traumatic) intracerebral haemorrhage (ICH) are at risk of recurrent ICH, ischaemic stroke, and other serious vascular events. We aimed to analyse these risks in population-based studies and compare them with the risks in RESTART, which assessed antiplatelet therapy after ICH.

METHODS

We pooled individual patient data from two prospective, population-based inception cohort studies of all patients with an incident firs-in-a-lifetime ICH in Oxfordshire, England (Oxford Vascular Study; April 1, 2002, to Sept 28, 2018) and Lothian, Scotland, UK (Lothian Audit of the Treatment of Cerebral Haemorrhage; June 1, 2010, to May 31, 2013). We quantified the absolute and relative risks of recurrent ICH, ischaemic stroke, or any serious vascular event (non-fatal stroke, non-fatal myocardial infarction, or vascular death), stratified by ICH location (lobar vs non-lobar) and comorbid atrial fibrillation (AF). We compared pooled event rates with those after allocation to avoid antiplatelet therapy in RESTART.

FINDINGS

Among 674 patients (mean age 74·7 years [SD 12·6], 320 [47%] men) with 1553 person-years of follow-up, 46 recurrent ICHs (event rate 3·2 per 100 patient-years, 95% CI 2·0-5·1) and 25 ischaemic strokes (1·7 per 100 patient-years, 0·8-3·3) were reported. Patients with lobar ICH (n=317) had higher risk of recurrent ICH (5·1 per 100 patient-years, 95% CI 3·6-7·2) than patients with non-lobar ICH (n=355; 1·8 per 100 patient-years, 1·0-3·3; hazard ratio [HR] 3·2, 95% CI 1·6-6·3; p=0·0010), but there was no evidence of a difference in the risk of ischaemic stroke (1·8 per 100 patient-years, 1·0-3·2, vs 1·6 per 100 patient-years, 0·6-4·4; HR 1·1, 95% CI 0·5-2·8). Conversely, there was no evidence of a difference in recurrent ICH rate in patients with AF (n=147; 3·3 per 100 patient-years, 95% CI 1·0-10·7) compared with those without (n=526; 3·2 per 100 patient-years, 2·2-4·7; HR 0·9, 95% CI 0·4-2·1), but the risk of ischaemic stroke was higher with AF (6·3 per 100 patient-years, 3·7-10·9, vs 0·7 per 100 patient-years, 0·1-5·6; HR 8·2, 3·3-20·3; p<0·0001), resulting in patients with AF having a higher risk of all serious vascular events than patients without AF (15·5 per 100 patient-years, 10·0-24·1, vs 6·8 per 100 patient-years, 3·6-12·5; HR 1·78, 95% CI 1·16-2·74; p=0·0090). Only for patients with lobar ICH without comorbid AF was the risk of recurrent ICH greater than the risk of ischaemic stroke (5·2 per 100 patient-years, 95% CI 3·6-7·5, vs 0·9 per 100 patient-years, 0·2-4·8; p=0·00034). Comparing data from the pooled population-based studies with that from patients allocated to not receive antiplatelet therapy in RESTART, there was no evidence of a difference in the rate of recurrent ICH (3·5 per 100 patient-years, 95% CI 1·9-6·0, vs 4·4 per 100 patient-years, 2·6-6·1) or ischaemic stroke (3·4 per 100 patient-years, 1·9-5·9, vs 5·3 per 100 patient-years, 3·3-7·2).

INTERPRETATION

The risks of recurrent ICH, ischaemic stroke, and all serious vascular events after ICH differ by ICH location and comorbid AF. These data enable risk stratification of patients in clinical practice and ongoing randomised trials.

FUNDING

UK Medical Research Council, Stroke Association, British Heart Foundation, Wellcome Trust, and the National Institute for Health Research Oxford Biomedical Research Centre.

Utility of image-guided external ventriculostomy: analysis of contemporary practice in the United Kingdom and Ireland

OBJECTIVE

Freehand external ventricular drain (EVD) insertion is associated with a high rate of catheter misplacement. Image-guided EVD placement with neuronavigation or ultrasound has been proposed as a safer, more accurate alternative with potential to facilitate proper placement and reduce catheter malfunction risk. This study aimed to determine the impact of image-guided EVD placement on catheter tip position and drain functionality.

METHODS

This study is a secondary analysis of a data set from a prospective, multicenter study. Data were collated for EVD placements undertaken in the United Kingdom and Ireland from November 2014 to April 2015. In total, 21 large tertiary care academic medical centers were included.

RESULTS

Over the study period, 632 EVDs were inserted and 65.9% had tips lying free-floating in the CSF. Only 19.6% of insertions took place under image guidance. The use of image guidance did not significantly improve the position of the catheter tip on postoperative imaging, even when stratified by ventricular size. There was also no association between navigation use and drain blockage.

CONCLUSIONS

Image-guided EVD placement was not associated with an increased likelihood of achieving optimal catheter position or with a lower rate of catheter blockage. Educational efforts should aim to enhance surgeons' ability to apply the technique correctly in cases of disturbed cerebral anatomy or small ventricles to reduce procedural risks and facilitate effective catheter positioning.

Raised cardiovascular disease mortality after central nervous system tumor diagnosis: analysis of 171,926 patients from UK and USA

BACKGROUND

Patients with central nervous system (CNS) tumors may be at risk of dying from cardiovascular disease (CVD). We examined CVD mortality risk in patients with different histological subtypes of CNS tumors.

METHODS

We analyzed UK(Wales)-based Secure Anonymized Information Linkage (SAIL) for 8743 CNS tumors patients diagnosed in 2000-2015, and US-based National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) for 163,183 patients in 2005-2015. We calculated age-, sex-, and calendar-year-adjusted standardized mortality ratios (SMRs) for CVD comparing CNS tumor patients to Wales and US residents. We used Cox regression models to examine factors associated with CVD mortality among CNS tumor patients.

RESULTS

CVD was the second leading cause of death for CNS tumor patients in SAIL (UK) and SEER (US). Patients with CNS tumors had higher CVD mortality than the general population (SAIL SMR = 2.64, 95% CI = 2.39-2.90, SEER SMR = 1.38, 95% CI = 1.35-1.42). Malignant CNS tumor patients had over 2-fold higher mortality risk in US and UK cohorts. SMRs for nonmalignant tumors were almost 2-fold higher in SAIL than in SEER. CVD mortality risk particularly cerebrovascular disease was substantially greater in patients diagnosed at age younger than 50 years, and within the first year after their cancer diagnosis (SAIL SMR = 2.98, 95% CI = 2.39-3.66, SEER SMR = 2.14, 95% CI = 2.03-2.25). Age, sex, race/ethnicity in USA, deprivation in UK and no surgery were associated with CVD mortality.

CONCLUSIONS

Patients with CNS tumors had higher risk for CVD mortality, particularly from cerebrovascular disease compared to the general population, supporting further research to improve mortality outcomes.

MYD88 L265P mutation in primary central nervous system lymphoma is associated with better survival: A single-center experience

BACKGROUND

The myeloid differentiation primary response gene (MYD88) mutation in primary central nervous system lymphomas (PCNSL) may be associated with unfavorable prognosis; however, current evidence remains limited. We aimed to characterize PCNSLs by integration of clinicopathological, molecular, treatment, and survival data.

METHODS

We retrospectively identified and validated 57 consecutive patients with PCNSLs according to the 2017 WHO classification of lymphoid neoplasms over 13 years. Formalin-fixed paraffin-embedded tumor samples underwent polymerase chain reaction assay to detect MYD88 mutation. We used Cox regression for survival analysis, including age, treatment, and MYD88 as covariates. We searched the literature for studies reporting demographics, treatment, MYD88, and survival of PCNSL patients and incorporated individual patient data into our analyses.

RESULTS

The median age was 66 years and 56% were women. All 57 patients had PCNSL of non-germinal center cell subtype and the majority (81%) received either single or combined therapies. There were 46 deaths observed over the median follow-up of 10 months. MYD88 mutation status was available in 41 patients of which 36 (88%) were mutated. There was an association between MYD88 mutation and better survival in the multivariable model (hazard ratio [HR] 0.277; 95% confidence interval [CI]: 0.09-0.83; P = .023) but not in a univariable model. After incorporating additional 18 patients from the literature, this association was reproducible (HR 0.245; 95% CI: 0.09-0.64; P = .004).

CONCLUSIONS

Adjusting for confounders, MYD88-mutant PCNSL appears to show improved survival. While further validation is warranted, detection of MYD88 mutation will aid the identification of patients who may benefit from novel targeted therapies.

Extent of MGMT promoter methylation modifies the effect of temozolomide on overall survival in patients with glioblastoma: a regional cohort study

BACKGROUND

MGMT methylation in glioblastoma predicts response to temozolomide but dichotomizing methylation status may mask the true prognostic value of quantitative MGMT methylation. This study evaluated whether extent of MGMT methylation interacts with the effect of temozolomide on overall survival.

METHODS

We included consecutive glioblastoma patients aged ≥16 years diagnosed (April 2012-May 2020) at a neuro-oncology center. All patients had quantitative MGMT methylation measured using pyrosequencing. Those with MGMT methylated tumors were stratified into high and low methylation groups based on a cut-off using Youden index on 2-year survival. Our accelerated failure time survival models included extent of MGMT methylation, age, postoperative Karnofsky performance score, extent of resection, temozolomide regimen, and radiotherapy.

RESULTS

There were 414 patients. Optimal cut-off point using Youden index was 25.9% MGMT methylation. The number of patients in the unmethylated, low and high methylation groups was 223 (53.9%), 81 (19.6%), and 110 (26.6%), respectively. In the adjusted model, high (hazard ratio [HR] 0.60, 95% confidence intervals [CI] 0.46-0.79, P = 0.005) and low (HR 0.67, 95% CI 0.50-0.89, P < 0.001) methylation groups had better survival compared to unmethylated group. There was no evidence for interaction between MGMT methylation and completed temozolomide regimen (interaction term for low methylation P = 0.097; high methylation P = 0.071). This suggests no strong effect of MGMT status on survival in patients completing temozolomide regimen. In patients not completing the temozolomide regimen, higher MGMT methylation predicted better survival (interaction terms P < 0.001).

CONCLUSIONS

Quantitative MGMT methylation may provide additional prognostic value. This is important when assessing clinical and research therapies.

CovidNeuroOnc: A UK multicenter, prospective cohort study of the impact of the COVID-19 pandemic on the neuro-oncology service

BACKGROUND

The COVID-19 pandemic has profoundly affected cancer services. Our objective was to determine the effect of the COVID-19 pandemic on decision making and the resulting outcomes for patients with newly diagnosed or recurrent intracranial tumors.

METHODS

We performed a multicenter prospective study of all adult patients discussed in weekly neuro-oncology and skull base multidisciplinary team meetings who had a newly diagnosed or recurrent intracranial (excluding pituitary) tumor between 01 April and 31 May 2020. All patients had at least 30-day follow-up data. Descriptive statistical reporting was used.

RESULTS

There were 1357 referrals for newly diagnosed or recurrent intracranial tumors across 15 neuro-oncology centers. Of centers with all intracranial tumors, a change in initial management was reported in 8.6% of cases (n = 104/1210). Decisions to change the management plan reduced over time from a peak of 19% referrals at the start of the study to 0% by the end of the study period. Changes in management were reported in 16% (n = 75/466) of cases previously recommended for surgery and 28% of cases previously recommended for chemotherapy (n = 20/72). The reported SARS-CoV-2 infection rate was similar in surgical and non-surgical patients (2.6% vs. 2.4%, P > .9).

CONCLUSIONS

Disruption to neuro-oncology services in the UK caused by the COVID-19 pandemic was most marked in the first month, affecting all diagnoses. Patients considered for chemotherapy were most affected. In those recommended surgical treatment this was successfully completed. Longer-term outcome data will evaluate oncological treatments received by these patients and overall survival.

Monitoring indirect impact of COVID-19 pandemic on services for cardiovascular diseases in the UK

OBJECTIVE

To monitor hospital activity for presentation, diagnosis and treatment of cardiovascular diseases during the COVID-19) pandemic to inform on indirect effects.

METHODS

Retrospective serial cross-sectional study in nine UK hospitals using hospital activity data from 28 October 2019 (pre-COVID-19) to 10 May 2020 (pre-easing of lockdown) and for the same weeks during 2018-2019. We analysed aggregate data for selected cardiovascular diseases before and during the epidemic. We produced an online visualisation tool to enable near real-time monitoring of trends.

RESULTS

Across nine hospitals, total admissions and emergency department (ED) attendances decreased after lockdown (23 March 2020) by 57.9% (57.1%-58.6%) and 52.9% (52.2%-53.5%), respectively, compared with the previous year. Activity for cardiac, cerebrovascular and other vascular conditions started to decline 1-2 weeks before lockdown and fell by 31%-88% after lockdown, with the greatest reductions observed for coronary artery bypass grafts, carotid endarterectomy, aortic aneurysm repair and peripheral arterial disease procedures. Compared with before the first UK COVID-19 (31 January 2020), activity declined across diseases and specialties between the first case and lockdown (total ED attendances relative reduction (RR) 0.94, 0.93-0.95; total hospital admissions RR 0.96, 0.95-0.97) and after lockdown (attendances RR 0.63, 0.62-0.64; admissions RR 0.59, 0.57-0.60). There was limited recovery towards usual levels of some activities from mid-April 2020.

CONCLUSIONS

Substantial reductions in total and cardiovascular activities are likely to contribute to a major burden of indirect effects of the pandemic, suggesting they should be monitored and mitigated urgently.

Tracking Excess Deaths (TRACKED) – an interactive online tool to monitor excess deaths associated with the COVID-19 pandemic in the United Kingdom

Background: We aimed to describe trends of excess mortality in the United Kingdom (UK) stratified by nation and cause of death, and to develop an online tool for reporting the most up to date data on excess mortality Methods: Population statistics agencies in the UK including the Office for National Statistics (ONS), National Records of Scotland (NRS), and Northern Ireland Statistics and Research Agency (NISRA) publish weekly mortality data. We used mortality data up to 22nd May in the ONS and the NISRA and 24th May in the NRS. The main outcome measures were crude mortality for non-COVID deaths (where there is no mention of COVID-19 on the death certificate) calculated, and excess mortality defined as difference between observed mortality and expected average of mortality from previous 5 years. Results: There were 56,961 excess deaths, of which 8,986 were non-COVID excess deaths. England had the highest number of excess deaths per 100,000 population (85) and Northern Ireland the lowest (34). Non-COVID mortality increased from 23rd March and returned to the 5-year average on 10th May. In Scotland, where underlying cause mortality data besides COVID-related deaths was available, the percentage excess over the 8-week period when COVID-related mortality peaked was: dementia 49%, other causes 21%, circulatory diseases 10%, and cancer 5%. We developed an online tool (TRACKing Excess Deaths - TRACKED) to allow dynamic exploration and visualisation of the latest mortality trends. Conclusions: Continuous monitoring of excess mortality trends and further integration of age- and gender-stratified and underlying cause of death data beyond COVID-19 will allow dynamic assessment of the impacts of indirect and direct mortality of the COVID-19 pandemic.

Tracking Excess Deaths (TRACKED) – an interactive online tool to monitor excess deaths associated with the COVID-19 pandemic in the United Kingdom

Background: We aimed to describe trends of excess mortality in the United Kingdom (UK) stratified by nation and cause of death, and to develop an online tool for reporting the most up to date data on excess mortality Methods: Population statistics agencies in the UK including the Office for National Statistics (ONS), National Records of Scotland (NRS), and Northern Ireland Statistics and Research Agency (NISRA) publish weekly mortality data. We used mortality data up to 22nd May in the ONS and the NISRA and 24th May in the NRS. The main outcome measures were crude mortality for non-COVID deaths (where there is no mention of COVID-19 on the death certificate) calculated, and excess mortality defined as difference between observed mortality and expected average of mortality from previous 5 years. Results: There were 56,961 excess deaths, of which 8,986 were non-COVID excess deaths. England had the highest number of excess deaths per 100,000 population (85) and Northern Ireland the lowest (34). Non-COVID mortality increased from 23rd March and returned to the 5-year average on 10th May. In Scotland, where underlying cause mortality data besides COVID-related deaths was available, the percentage excess over the 8-week period when COVID-related mortality peaked was: dementia 49%, other causes 21%, circulatory diseases 10%, and cancer 5%. We developed an online tool (TRACKing Excess Deaths - TRACKED) to allow dynamic exploration and visualisation of the latest mortality trends. Conclusions: Continuous monitoring of excess mortality trends and further integration of age- and gender-stratified and underlying cause of death data beyond COVID-19 will allow dynamic assessment of the impacts of indirect and direct mortality of the COVID-19 pandemic.

Longer-term (≥ 2 years) survival in patients with glioblastoma in population-based studies pre- and post-2005: a systematic review and meta-analysis

Translation of survival benefits observed in glioblastoma clinical trials to populations and to longer-term survival remains uncertain. We aimed to assess if ≥ 2-year survival has changed in relation to the trial of radiotherapy plus concomitant and adjuvant temozolomide published in 2005. We searched MEDLINE and Embase for population-based studies with ≥ 50 patients published after 2002 reporting survival at ≥ 2 years following glioblastoma diagnosis. Primary endpoints were survival at 2-, 3- and 5-years stratified by recruitment period. We meta-analysed survival estimates using a random effects model stratified according to whether recruitment ended before 2005 (earlier) or started during or after 2005 (later). PROSPERO registration number CRD42019130035. Twenty-three populations from 63 potentially eligible studies contributed to the meta-analyses. Pooled 2-year overall survival estimates for the earlier and later study periods were 9% (95% confidence interval [CI] 6-12%; n/N = 1,488/17,507) and 18% (95% CI 14-22%; n/N = 5,670/32,390), respectively. Similarly, pooled 3-year survival estimates increased from 4% (95% CI 2-6%; n/N = 325/10,556) to 11% (95% CI 9-14%; n/N = 1900/16,397). One study with a within-population comparison showed similar improvement in survival among the older population. Pooled 5-year survival estimates were 3% (95% CI 1-5%; n/N = 401/14,919) and 4% (95% CI 2-5%; n/N = 1,291/28,748) for the earlier and later periods, respectively. Meta-analyses of real-world data suggested a doubling of 2- and 3-year survival in glioblastoma patients since 2005. However, 5-year survival remains poor with no apparent improvement. Detailed clinically annotated population-based data and further molecular characterization of longer-term survivors may explain the unchanged survival beyond 5 years.

Ventriculoperitoneal shunt insertion in human immunodeficiency virus infected adults: a systematic review and meta-analysis

BACKGROUND

Hydrocephalus is a common, life threatening complication of human immunodeficiency virus (HIV)-related central nervous system opportunistic infection which can be treated by insertion of a ventriculoperitoneal shunt (VPS). In HIV-infected patients there is concern that VPS might be associated with unacceptably high mortality. To identify prognostic indicators, we aimed to compare survival and clinical outcome following VPS placement between all studied causes of hydrocephalus in HIV infected patients.

METHODS

The following electronic databases were searched: The Cochrane Central Register of Controlled Trials, MEDLINE (PubMed), EMBASE, CINAHL Plus, LILACS, Research Registry, the metaRegister of Controlled Trials, ClinicalTrials.gov, African Journals Online, and the OpenGrey database. We included observational studies of HIV-infected patients treated with VPS which reported of survival or clinical outcome. Data was extracted using standardised proformas. Risk of bias was assessed using validated domain-based tools.

RESULTS

Seven Hunderd twenty-three unique study records were screened. Nine observational studies were included. Three included a total of 75 patients with tuberculous meningitis (TBM) and six included a total of 49 patients with cryptococcal meningitis (CM). All of the CM and two of the TBM studies were of weak quality. One of the TBM studies was of moderate quality. One-month mortality ranged from 62.5-100% for CM and 33.3-61.9% for TBM. These pooled data were of low to very-low quality and was inadequate to support meta-analysis between aetiologies. Pooling of results from two studies with a total of 77 participants indicated that HIV-infected patients with TBM had higher risk of one-month mortality compared with HIV non-infected controls (odds ratio 3.03; 95% confidence-interval 1.13-8.12; p = 0.03).

CONCLUSIONS

The evidence base is currently inadequate to inform prognostication in VPS insertion in HIV-infected patients. A population-based prospective cohort study is required to address this, in the first instance.

Subarachnoid haemorrhage with negative initial neurovascular imaging: a systematic review and meta-analysis

Background

In patients with spontaneous subarachnoid haemorrhage (SAH), a vascular cause for the bleed is not always found on initial investigations. This study aimed to systematically evaluate the delayed investigation strategies and clinical outcomes in these cases, often described as “non-aneurysmal” SAH (naSAH).

Methods

A systematic review was performed in concordance with the PRISMA checklist. Pooled proportions of primary outcome measures were estimated using a random-effects model.

Results

Fifty-eight studies were included (4473 patients). The cohort was split into perimesencephalic naSAH (PnaSAH) (49.9%), non-PnaSAH (44.7%) and radiologically negative SAH identified on lumbar puncture (5.4%). The commonest initial vascular imaging modality was digital subtraction angiography. A vascular abnormality was identified during delayed investigation in 3.9% [95% CI 1.9–6.6]. There was no uniform strategy for the timing or modality of delayed investigations. The pooled proportion of a favourable modified Rankin scale outcome (0–2) at 3–6 months following diagnosis was 92.0% [95% CI 86.0–96.5]. Complications included re-bleeding (3.1% [95% CI 1.5–5.2]), hydrocephalus (16.0% [95% CI 11.2–21.4]), vasospasm (9.6% [95% CI 6.5–13.3]) and seizure (3.5% [95% CI 1.7–5.8]). Stratified by bleeding pattern, we demonstrate a higher rate of delayed diagnoses (13.6% [95% CI 7.4–21.3]), lower proportion of favourable functional outcome (87.2% [95% CI 80.1–92.9]) and higher risk of complications for non-PnaSAH patients.

Conclusion

This study highlights the heterogeneity in delayed investigations and outcomes for patients with naSAH, which may be influenced by the initial pattern of bleeding. Further multi-centre prospective studies are required to clarify optimal tailored management strategies for this heterogeneous group of patients.

Electronic supplementary material

The online version of this article (10.1007/s00701-019-04025-w) contains supplementary material, which is available to authorized users.

Influence of Antiplatelet and Anticoagulant Drug Use on Outcomes after Chronic Subdural Hematoma Drainage

We aim to describe the outcomes after chronic subdural hematoma drainage (CSDH) management in a large cohort of patients on antithrombotic drugs, either antiplatelets or anticoagulants, at presentation and to inform clinical decision making on the timing of surgery and recommencement of these drugs. We used data from a previous UK-based multi-center, prospective cohort study. Outcomes included recurrence within 60 days, functional outcome at discharge, and thromboembolic event during hospital stay. We performed Cox regression on recurrence and multiple logistic regression on functional outcome. There were 817 patients included in the analysis, of which 353 (43.2%) were on an antithrombotic drug at presentation. We observed a gradual reduction in risk of recurrence for patients during the 6 weeks post-CSDH surgery. Neither antiplatelet nor anticoagulant drug use influenced risk of CSDH recurrence (hazard ratio, 0.93; 95% confidence interval [CI], 0.58–1.48; p = 0.76) or persistent/worse functional impairment (odds ratio, 1.08; 95% CI, 0.76–1.55; p = 0.66). Delaying surgery after cessation of antiplatelet drug did not affect risk of bleed recurrence. There were 15 in-hospital thromboembolic events recorded. Events were more common in the group pre-treated with antithrombotic drugs (3.3%) compared to the non-antithrombotic group (0.9%). Patients on an antithrombotic drug pre-operatively were at higher risk of thromboembolic events with no excess risk of bleed recurrence or worse functional outcome after CSDH drainage. The data did not support delaying surgery in patients on antithrombotic therapy. In the absence of a randomized controlled trial, early surgery and early antithrombotic recommencement should be considered in those at high risk of thromboembolic events.

Outcomes following surgery in subgroups of comatose and very elderly patients with chronic subdural hematoma

Increasing age and lower pre-operative Glasgow coma score (GCS) are associated with worse outcome after surgery for chronic subdural haematoma (CSDH). Only few studies have quantified outcomes specific to the very elderly or comatose patients. We aim to examine surgical outcomes in these patient groups. We analysed data from a prospective multicentre cohort study, assessing the risk of recurrence, death, and unfavourable functional outcome of very elderly (≥ 90 years) patients and comatose (pre-operative GCS ≤ 8) patients following surgical treatment of CSDH. Seven hundred eighty-five patients were included in the study. Thirty-two (4.1%) patients had pre-operative GCS ≤ 8 and 70 (8.9%) patients were aged ≥ 90 years. A higher proportion of comatose patients had an unfavourable functional outcome (38.7 vs 21.7%; p = 0.03), although similar proportion of comatose (64.5%) and non-comatose patients (61.8%) functionally improved after surgery (p = 0.96). Compared to patients aged < 90 years, a higher proportion of patients aged ≥ 90 years had unfavourable functional outcome (41.2 vs 20.5%; p < 0.01), although approximately half had functional improvement following surgery. Mortality risk was higher in both comatose (6.3 vs 1.9%; p = 0.05) and very elderly (8.8 vs 1.1%; p < 0.01) groups. There was a trend towards a higher recurrence risk in the comatose group (19.4 vs 9.5%; p = 0.07). Surgery can still provide considerable benefit to very elderly and comatose patients despite their higher risk of morbidity and mortality. Further research would be needed to better identify those most likely to benefit from surgery in these groups.

Characteristics of Randomized Trials Focusing on Stroke due to Intracerebral Hemorrhage: Systematic Review

BACKGROUND AND PURPOSE

The absence of treatments for intracerebral hemorrhage with significant consistent benefit in randomized controlled trials (RCTs) could be because of lack of treatment efficacy or the design of RCTs.

METHODS

We searched the Cochrane Stroke Group Trials Register in December 2015 for completed and published RCTs reporting clinical outcome in adults with intracerebral hemorrhage. We collected data on publication year and language, study characteristics, and effect size. We regarded RCTs to be at lower risk of bias if they performed ≥2 of describing randomization, using blinding, or specifying the primary outcome. We registered this systematic review (PROSPERO, international prospective register of systematic reviews CRD42016051103).

RESULTS

We found 136 eligible RCTs: 57% were phase II, 76% were single center, 98% studied acute treatments, 49% involved drug interventions, 24% were placebo-controlled, the primary outcome was death or disability in 30%, and median sample size was 77 (interquartile range, 47-160). Forty-six percent explained randomization, 24% blinded treatment allocation, and 24% specified the primary outcome such that 38 (28%) were at lower risk of bias. RCTs at lower risk of bias were more likely to use multicenter recruitment (adjusted odds ratio, 6.95; 95% confidence interval, 2.2-21.5) and be published in English (adjusted odds ratio, 12.9, 95% confidence interval, 2.7-62.5). RCTs with larger sample sizes were independently more likely to be phase III/IV (P<0.01) and use multicenter recruitment (P<0.01). RCTs at lower risk of bias had smaller pooled treatment effects on death/disability (P=0.02).

CONCLUSIONS

Intracerebral hemorrhage RCTs have often been at high risk of bias, and these RCTs have been characterized by small sample sizes and larger effect sizes.

Association between diabetes mellitus and the occurrence and outcome of intracerebral hemorrhage

OBJECTIVE

Whether diabetes mellitus (DM) is a risk factor for spontaneous intracerebral hemorrhage (ICH) and influences outcome after ICH remains unclear.

METHODS

One reviewer searched Ovid MEDLINE and Embase 1980-2014 inclusive for studies investigating the associations between DM and ICH occurrence or DM and ICH case fatality. Two reviewers independently confirmed each study's eligibility, assessed risk of bias, and extracted data. One reviewer combined studies using random effects meta-analysis.

RESULTS

Nineteen case-control studies involving 3,397 people with ICH and 5,747 people without ICH found an association between DM and ICH occurrence (unadjusted odds ratio [OR] 1.23, 95% confidence interval [CI] 1.04-1.45; I(2) = 22%), which did not differ between 17 hospital-based and 2 population-based studies (pdiff = 0.70), and was similar in the 16 studies that controlled for age and sex (unadjusted OR 1.15, 95% CI 0.95-1.40; I(2) = 14%). This association was not identified in 3 population-based cohort studies in which ICH occurred in 38 (0.66%) of 5,724 people with DM and 448 (0.57%) of 78,702 people without DM (unadjusted risk ratio [RR] 1.27, 95% CI 0.68-2.36; I(2) = 69%). DM was associated with a higher case fatality by 30 days or hospital discharge in 18 cohort studies involving 813 people with DM and 3,714 people without DM (unadjusted RR 1.52, 95% CI 1.28-1.81; I(2) = 49%).

CONCLUSIONS

The findings suggest that there may be modest associations between DM and ICH occurrence and outcome, but further information from large, population-based studies that account for confounding is required before the association can be confirmed.

Epidemiology of Intracerebral Haemorrhage

INTRODUCTION

Intracerebral haemorrhage (ICH) has an overall incidence of 24.6 per 100,000 person-years and is associated with a high case fatality. Understanding the risk factors for ICH occurrence informs primary prevention strategies. This article provides an update on the current global patterns of ICH incidence and the common and emerging risk factors associated with ICH.

METHODS

We searched Ovid Medline (from 1980 to Oct 2014) for systematic reviews that addressed the epidemiology of ICH and for recent original studies that revealed new insights into the frequency of and the risk factors associated with ICH.

RESULTS

The incidence of ICH has not changed over the last 30 years, and this consistency is thought to be due to changes in the risk factor profiles of ICH patients. It appears that ICH is more common in men and during the winter months. ICH affects Asian populations more frequently than other populations. In addition to the known risk factors of hypertension and increasing age, alcohol consumption, the presence of the apolipoprotein ε2 or ε4 allele, extremes of body mass index, diabetes, and ophthalmic conditions have been suggested to be associated with ICH. Factors associated with a reduced risk of ICH include hypercholesterolaemia and a diet high in fruits and vegetables.

CONCLUSIONS

The overall incidence of ICH has remained unchanged, but its regional incidence varies by race, sex, season and geographical location. In high income countries, the beneficial effect of improving blood pressure control may be counterbalanced by the increased use of antithrombotic drugs. Emerging modifiable risk factors include alcohol consumption, body mass index, diabetes, and fruit and vegetable intake, all of which may be amenable to interventions for the primary prevention of ICH (as well as many other diseases).