Ethnicity in neuro-oncology research: How are we doing and how can we do better?

PURPOSE: This study systematically reviews and meta-analyses the extent of ethnic minority representation in neuro-oncology Phase III and IV clinical trials, explores the effect of ethnicity on outcomes, and identifies predictors for the inclusion of ethnicity data in publications. METHODS: Adhering to PRISMA guidelines, we conducted a comprehensive literature search across multiple databases, on Phase III and IV trials in neuro-oncology that reported on adult and/or paediatric subjects. Through meta-analysis, we synthesized information on overall survival, event-free survival, and the incidence of adverse outcomes across ethnicities. RESULTS: From 448 identified articles, a fraction reported ethnicity data, with an even smaller number providing outcome data stratified by ethnicity. Most study participants were identified as White, underscoring a significant underrepresentation of minorities. Our meta-analysis did not reveal significant outcome differences by ethnicity, which may be attributed to the limited and inadequate reporting of data. Predictors for including ethnicity data were identified, including trials in North America(OR2.39, 95%CI 1.18-5.12, p < 0.02),trials of drugs or biologic agents(OR 5.28, 95%CI 1.43-3.42, p < 0.05),and trials funded by charities(OR 2.28, 95% CI 1.04-5.27, p < 0.05) or pharmaceutical companies(OR 3.98, 95% CI 1.60-10.0, p < 0.005). CONCLUSION: The underrepresentation of minorities in neuro-oncology clinical trials and the inadequately characterized impact of ethnicity on treatment outcomes highlight a critical need for more inclusive recruitment strategies and improved reporting standards. Change is necessary to ensure trials reflect the diversity of the patient population, which is essential for developing tailored strategies and improving outcomes. Future research should prioritize understanding the role of ethnicity in neuro-oncology to facilitate personalized treatment approaches.

The role of astrocytes in brain metastasis at the interface of circulating tumour cells and the blood brain barrier.

Tumour metastasis to the brain is a complex process involving crosstalk between the circulating tumour cells and the blood brain barrier (BBB). Astrocytes, which reside in the abluminal surface of the microvasculature of the BBB, are now known to play an essential role in tumour cell migration and invasion into the brain parenchyma. For instance, pro-inflammatory astrocyte secretions, including TNF-α, IL-6, CXCL10 as well as polyunsaturated fatty acids interact with circulating tumour cells to promote migration and proliferation. Additionally, astrocyte and tumour cell derived MMPs play a vital role in tumour cell invasion through the BBB. Understanding these complex interactions between tumour cells and astrocytes in the tumour microenvironment may contribute to the development of novel therapeutics for brain metastasis. Therefore, in this review, we present key interactions within the neurovascular unit of the BBB in the tumour microenvironment that significantly aids cancer metastasis, focusing particularly on astrocytes.