Innovations in Neuro-Oncology

Temporal trends in neurosurgical volume and length of stay in a public healthcare system: A decade in review with a focus on the COVID-19 pandemic

Background

Over the past decade, neurosurgical interventions have experienced changes in operative frequency and postoperative length of stay (LOS), with the recent COVID-19 pandemic significantly impacting these metrics. Evaluating these trends in a tertiary National Health Service center provides insights into the impact of surgical practices and health policy on LOS and is essential for optimizing healthcare management decisions.

Methods

This was a single tertiary center retrospective case series analysis of neurosurgical procedures from 2012 to 2022. Factors including procedure type, admission urgency, and LOS were extracted from a prospectively maintained database. Six subspecialties were analyzed: Spine, Neuro-oncology, Skull base (SB), Functional, Cerebrospinal fluid (CSF), and Peripheral nerve (PN). Mann-Kendall temporal trend test and exploratory data analysis were performed.

Results

19,237 elective and day case operations were analyzed. Of the 6 sub-specialties, spine, neuro-oncology, SB, and CSF procedures all showed a significant trend toward decreasing frequency. A shift toward day case over elective procedures was evident, especially in spine (P < 0.001), SB (tau = 0.733, P = 0.0042), functional (tau = 0.156, P = 0.0016), and PN surgeries (P < 0.005). Over the last decade, decreasing LOS was observed for neuro-oncology (tau = -0.648, P = 0.0077), SB (tau = -0.382, P = 0.012), and functional operations, a trend which remained consistent during the COVID-19 pandemic (P = 0.01). Spine remained constant across the decade while PN demonstrated a trend toward increasing LOS.

Conclusion

Most subspecialties demonstrate a decreasing LOS coupled with a shift toward day case procedures, potentially attributable to improvements in surgical techniques, less invasive approaches, and increased pressure on beds. Setting up extra dedicated day case theaters could help deal with the backlog of procedures, particularly with regard to the impact of COVID-19.

Applications of organoid technology to brain tumors

Lacking appropriate model impedes basic and preclinical researches of brain tumors. Organoids technology applying on brain tumors enables great recapitulation of the original tumors. Here, we compared brain tumor organoids (BTOs) with common models including cell lines, tumor spheroids, and patient-derived xenografts. Different BTOs can be customized to research objectives and particular brain tumor features. We systematically introduce the establishments and strengths of four different BTOs. BTOs derived from patient somatic cells are suitable for mimicking brain tumors caused by germline mutations and abnormal neurodevelopment, such as the tuberous sclerosis complex. BTOs derived from human pluripotent stem cells with genetic manipulations endow for identifying and understanding the roles of oncogenes and processes of oncogenesis. Brain tumoroids are the most clinically applicable BTOs, which could be generated within clinically relevant timescale and applied for drug screening, immunotherapy testing, biobanking, and investigating brain tumor mechanisms, such as cancer stem cells and therapy resistance. Brain organoids co-cultured with brain tumors (BO-BTs) own the greatest recapitulation of brain tumors. Tumor invasion and interactions between tumor cells and brain components could be greatly explored in this model. BO-BTs also offer a humanized platform for testing the therapeutic efficacy and side effects on neurons in preclinical trials. We also introduce the BTOs establishment fused with other advanced techniques, such as 3D bioprinting. So far, over 11 brain tumor types of BTOs have been established, especially for glioblastoma. We conclude BTOs could be a reliable model to understand brain tumors and develop targeted therapies.

Bone marrow-derived mesenchymal stem cells expressing BMP2 suppress glioma stem cell growth and stemness through Bcl-2/Bax signaling

Objectives

To find an effective molecule that controls glioma stem cell (GSC) proliferation and differentiation for the development of future therapeutic interventions against glioblastoma.

Material and Methods

Bone marrow-derived mesenchymal stem cells (BMSCs) were infected with a lentiviral vector to express BMP2. Cell viability, cell counting, and tumor sphere formation assays, as well as flow cytometry, immunofluorescence staining, and Western blotting were used to investigate the effects of BMSC-BMP2 on GSCs.

Results

The results of flow cytometry and the CKK-8 assay showed that BMSC-BMP2 induced GSC apoptosis while inhibiting proliferation. BMSC-BMP2 decreased GSC neurosphere formation and neurospheres' transverse and vertical diameter. Meanwhile, BMSC-BMP2 downregulated GSC Nanog and OCT4 expression levels, suggesting stemness inhibition. Western blotting showed that BMSC-BMP2 increased Bax protein expression and significantly decreased Bcl-2 protein expression. Accordingly, the Bcl-2/Bax ratio increased.

Conclusion

BMSC-BMP2 could effectively inhibit GSC proliferation, induce GSC apoptosis, and decrease GSC stemness, thereby providing a novel strategy for treating malignant glioma.

Thioredoxin System and miR-21, miR-23a/b and let-7a as Potential Biomarkers for Brain Tumor Progression: Preliminary Case Data

BACKGROUND

The thioredoxin system and microRNAs (miRNAs) are potential targets for both cancer progression and treatment. However, the role of miRNAs and their relation with the expression profile of thioredoxin system in brain tumor progression remains unclear.

METHODS

In this study, we aimed to determine the expression profiles of redox components Trx-1, TrxR-1 and PRDX-1, and oncogenic miR-21, miR-23a/b and let-7a and oncosuppressor miR-125 in different brain tumor tissues and their association with increasing tumor grade. We studied Trx-1, TrxR-1, and PRDX-1 messenger RNA expression levels by quantitative real-time polymerase chain reaction and protein levels by Western blot and miR-23a, miR-23b, miR-125a, miR-21, and let-7a miRNA expression levels by quantitative real-time polymerase chain reaction in 16 glioma, 15 meningioma, 5 metastatic, and 2 benign tumor samples. We also examined Trx-1, TrxR-1, and PRDX-1 protein levels in serum samples of 36 patients with brain tumor and 37 healthy volunteers by enzyme-linked immunosorbent assay.

RESULTS

We found that Trx-1, TrxR-1, and PRDX-1 presented high messenger RNA expression but low protein expression in low-grade brain tumor tissues, whereas they showed higher protein expression in sera of patients with low-grade brain tumors. miR-23b, miR-21, miR-23a, and let-7a were highly expressed in low-grade brain tumor tissues and positively correlated with the increase in thioredoxin system activity.

CONCLUSIONS

Our findings showed that Trx-1, TrxR-1, miR-21, miR-23a/b, and let-7a might be used for brain tumor diagnosis in the clinic. Further prospective studies including molecular pathway analyses are required to validate the miRNA/Trx system regulatory axis in brain tumor progression.

Patterns and outcomes of neurosurgery in England over a five-year period: A national retrospective cohort study

BACKGROUND

Neurosurgical practice has seen major changes over several decades. There are no recent evaluations of national neurosurgical practice. The aim of this observational study was to describe neurosurgical practice in England and to use outcomes to assess and benchmark the quality of care in neurosurgery.

MATERIAL AND METHODS

This national retrospective cohort study analysed Hospital Episode Statistics (HES) data from April 2013 to March 2018 for all adult admissions with a specialty code for neurosurgery. The epidemiology of patients and RCS Charlson comorbidities were derived and procedure incidence rates per 100,000 person-years calculated. Post-operative outcomes for elective and non-elective patients included: median length of stay, the proportion of patients requiring additional inpatient neurosurgical procedures, the proportion of patients discharged to their usual address, and in-hospital mortality rates.

RESULTS

During the 5-year study period, there were 371,418 admissions to neurosurgery. The proportion of admissions involving a neurosurgical procedure was 77.3% (n = 287,077). Of these, 45% were for cranial surgery and 37% for spinal. Overall, 68.3% were elective procedures. The incidence rates of most procedures were low (<20 per 100,000 person-years). Following elective neurosurgical procedures, in-hospital mortality rates for cranial and spinal surgery were 0.5% (95% CI, 0.5-0.6) and 0.1% (95% CI, 0.04-0.1), respectively. After non-elective neurosurgery, mortality rates were 7.4% (95% CI, 7.2-7.6) and 1.3% (95% CI, 1.2-1.5) for cranial and spinal surgery, respectively. Approximately 1 in 4 patients had additional procedures following non-elective cranial surgery (24%; 95% CI, 23.6-24.3). Outcomes were highly variable across different subspecialty areas.

CONCLUSIONS

The incidence rates of neurosurgical procedures are low within England, and neurosurgical units have a high volume of non-surgical admissions. In-hospital mortality rates after elective neurosurgery are low but there may be opportunities for quality improvement programmes to improve outcomes for non-elective surgery as well as ensuring equitable access to treatment.