Neuro-oncological research output in Africa: a scoping review of primary brain tumors

Research shows that individuals of African ancestry, particularly those residing in Africa, suffer from an unfortunate amount of under-representation in cancer research, including (clinical trials) worldwide [1]. The lack of neuro-oncology research focused on African populations results in knowledge gaps about disease patterns, treatment responses, and outcomes for these groups [2]. In addition to the growing African population and burden of cancer, we must take action to reverse this trend [3]. African populations bear a higher burden of cancer compared to general populations, and they are affected by cancer in forms that are more aggressive and challenging to manage [4]. Globally, a large population of Africans can trace their roots to Western Africa, and it is easily argued that data from this region can help improve the global health disparities. Considering these statistics and facts, African oncologists have the prerogative to lead the way in developing research to improve the health of the African population [5].

Brain tumors were once thought to be rare among the African population [6]. However, there is a shift in the perception of the African neuro-oncological disease burden among practitioners. However, due to the lack of organized nationwide and continent-wide databases of brain tumor incidence, epidemiological studies can be challenging [7]. No previous assessment of neuro-oncological research production originated from Africa in the first 20 years of this century. Hence, it is essential to analyze areas of strength and deficiency and give recommendations based on analyzed data.

Furthermore, this will allow us to advocate for increasing the quality, quantity, and diversity of published articles and encourage neuro-oncologists to participate more in academic research to pave the way for a healthier tomorrow for all African peoples and mend the medical and academic gap between the African continents and the rest of the world.

We aimed to analyze current research output and potentially predict future trends in neuro-oncological research in Africa by investigating deficits in the field. This study will help us identify which countries are performing well in this field, which ones face challenges, and how to solve them. Therefore, targeted interventions can be applied to overcome these challenges.

Our study showed that most articles about neuro-oncology published in Africa are primary studies, mainly retrospective cohorts. Most of the articles were published by African authors, with the peak of studies in 2019 rising. Clinical practice was the focus of researchers talking about surgery; the malignant type was predominant, and the type of neurological tumor most evident in research articles was neuroblastoma.

We acknowledge the difference in collaboration patterns between our study and the East African one [11]. Compared to the collaboration trend in East Africa, the predominance of articles authored solely by Africans in our research reflects the distinct nationalities contributing to our dataset—specifically, Nigerian, Egyptian, South African, Moroccan, and Tunisian researchers.

The number of neurosurgeons in Africa is considered minimal compared to Europe and USA. This results in decreased healthcare provided to neuro-oncological patients. The Nigerian Academy of Neurological Surgeons reported 81 neurosurgeons in Nigeria in June 2018. Compared to the average for sub-Saharan Africa, which is 1 neurosurgeon for every 2 million people, this translates to a neurosurgeon-to-resident ratio of 1 for every 2.4 million people [12, 13]. Europe has a ratio of 1 for every 100,000 inhabitants, as opposed to the USA, where it is 1 for every 62,500 [12]. A study published in 2016 found that the low number of neuroscientists is mainly caused by the technical and budgetary shortcomings in neurology training programs [14]. A lack of a defined policy on neurological illnesses and the unstable political environment in Africa has caused some of the continent’s neuroscientists to migrate to other continents.

Organizations like The Society of Neuroscientists of Africa (SONA), the International Brain Research Organization (IBRO), and national neuroscience societies offer domestic training for African neuroscientists [15]. Despite World Neurosurgical Association programs, challenges persist in prerequisites and facilities. Historically contributed to neurologist training by centers in Morocco, Egypt, Senegal, Tunisia, Nigeria, Ivory Coast, and South Africa, while NPOs collaborate for ongoing support and training in African universities [15].

Moreover, neurologists play a vital role in neurosurgeons in the neuro-oncology field, and as previously mentioned, a multidisciplinary team is required. However, there is also a shortage of neurologists in many African countries, such as South Sudan and Eritrea, with no neurologists, while Egypt (3108 neurologists) and South Africa (165 neurologists) have an adequate number of neurologists [16].

Our study identified 200 neuro-oncology articles published in African countries until January 2023. In comparison, a study in East African countries [11] found 36 articles by December 2020. Notably, our study revealed an article from Somalia, which the East African study reported as having none. Most of our articles were primary research, primarily retrospective cohort, echoing patterns observed in the East African study. Clinical care topics constituted 80% of our articles, aligning with the East African study’s emphasis on patient care (67%) [11].

Meningiomas are the only subtype of intracranial neoplasm, while gliomas are the most frequent subtype of primary parenchymal tumors, according to a large body of international research [11, 17]. Our study showed that the most mentioned type of neurological tumor in the research papers was neuroblastoma, followed by glioma and meningioma. However, the East African study showed that meningioma represents the largest proportion (43.3%) of common neurological tumors, followed by glioma (33.7%). This is like the report from the Central Brain Tumor Registry of the USA (CBTRUS), which showed that meningiomas made up 37.6% and gliomas made up 25.5% of all primary brain and other central nervous system tumors, respectively, in 2019 [18]. In the East African study [11], the majority of studies (47%) included adult and pediatric tumors, followed by pediatric only (31%) and then adult only (22%). However, our study showed that most were adult tumors, followed by pediatric, and then articles about both. Patients under 18 comprise half of the population in several East African areas.

Our study highlights most articles in non-African journals, indicating a limited presence in African institutes. The reported 65.2% absence of journal clubs aligns with challenges in fostering critical thinking [19]. Compared to the 85% inclusion in American schools, regular journal clubs enhance neurosurgery knowledge [20, 21].

In Africa, the limited availability of training slots (176) and neurosurgical programs (76) poses challenges for specialized medical training, especially in Sub-Saharan Africa, because the majority of programs are in North Africa [22]. While collaborative projects can enhance education and research, the scarcity of fellowship opportunities impedes professional advancement.

The study focuses on CNS tumor research in Africa, emphasizing the importance of research for clinical outcomes and global progress. However, limitations include potential oversight of studies conducted abroad by African neurosurgeons and the reliance on affiliations for location determination. The study calls for increased neurosurgery teaching, greater engagement of African neurosurgeons in research, and enhanced collaboration with foreign authors and institutions.

This scoping review reveals an increasing interest in neuro-oncological research in Africa. The findings highlight the need for ongoing efforts to address issues with clinical practice and public health related to central nervous system tumors in the continent. Future studies should focus on filling the knowledge gaps and investigating novel methods for neuro-oncological conditions that affect African populations in terms of prevention, diagnosis, treatment, and management strategies.