Mapping evidence on the distribution of paediatric cancers in sub-Saharan Africa: a scoping review protocol

Globally, cancer remains the leading cause of disease-related death in children [1]. The estimated 5-year prevalence of cancers in 2018 for children 14 years and below is 606,982 [2]. Children represent 41% of the total population residing in Africa, and in some of these regions, children constitute more than half of the population [1]. In 2018, the estimated number of prevalent paediatric cancers is 103,016 [2]. The most prevalent cancers in children 14 years and below are leukaemia (19,246), kidney cancer (14,002), non-Hodgkin lymphoma (13, 368), brain and nervous system (6317) and Kaposi sarcoma (3101) [2]. The prevalence rates in Africa may be underestimated due to a lack of proper diagnosis and childhood cancer registration [3, 4]. The actual distribution of these malignancies in SSA is therefore not truly reflected because of poor health care systems and competing health care needs, making it difficult to develop paediatric cancer control programmes [5].

Paediatric cancers receive little attention from local policymakers and global health agencies due to the fact that it accounts for a minor fraction of deaths ranging from 0.5% in high-income countries (HIC) to approximately 5% in low-income countries [6]. The absence of comprehensive national paediatric strategies results in a lack of access to care for a majority of children with cancer in low-middle-income countries (LMICs) [7]. In an effort to improve the survival rates of children affected by cancer, the International Agency for Research in Cancer (IARC) made a collaboration with cancer registries and partners around the world [6]. They work closely to generate and provide global data which is important in developing and monitoring efficient strategies for the early detection and care for paediatric cancer [4, 6]. As all registries must comply with standard criteria, this international collaboration will bring about an improvement in local data and information. However, this poses a challenge in SSA as there is limited information on the distribution of various childhood malignancies in Africa, and the policy is based on information from other countries [1].

Infection with HIV increases the risk of cancer [8]. In HICs, it is estimated that 2.5% of children with HIV will develop cancer [9]. More than two-thirds of people living with HIV reside in SSA [9] and life expectancy has increased due to the introduction of highly active antiretroviral treatment (HAART). Most studies linking cancer to HIV infection are based on the adult population [10]. To provide a better understanding of the spectrum of HIV-associated cancers in the paediatric population and subsequently come up with feasible and effective strategies for their diagnosis and cure, there is a need for well-planned population-based studies [9]. The starting point for effective analytical epidemiological studies will be understanding the trends of these malignancies prior and in the HIV era.

Therefore, this scoping review aims to map evidence on the distribution of paediatric cancers in sub-Saharan Africa. Understanding the distribution of paediatric cancers will help provide the basis for the design of sound clinical and public health programmes. It will provide a visual insight of the extent and magnitude of the prevalence, incidence and mortality rates of paediatric cancers in the SSA region. It also provides the basis for the design of research programmes in individual countries that will support the health care effort required to prevent, cure and subsequently increase the survival rates in paediatric cancer patients SSA.

After charting the data, a descriptive overview of the studies will be presented in a narrative format. An account of the number of studies, research methods used, gender percentage, types and distribution of paediatric cancers and outcomes will be described in this narrative. The analysis will be mainly based on mapping the country-specific outcomes emerging from the studies and a numerical summary of these outcomes will be conducted. A table for the latter will be produced. In analysing the outcomes, a comparison of the malignancies amongst the SSA countries will be made. A geographical map of the individual countries reported in the studies and charts showing the types of cancers will also be produced and presented in the results section. We will also analyse the meanings of the findings in relation to the aim of the study and the implications of these for future research, policy and practice in SSA.

The objective of this scoping review is to map existing literature for evidence on the distribution of paediatric cancers, epidemiological trends in paediatric cancers and trends in paediatric cancer in relation to HIV in SSA. A map on the distribution of childhood cancers in the SSA region will give a reflection on the disease burden, assessment and identification of the aetiology and risk factors. There is a high demand of evidence synthesis studies that are applicable to the decision-makers’ local context, to help improve health systems’ performance and subsequently improve health outcomes [13].

This study will be the first to map existing literature for evidence on the distribution of childhood cancers in the SSA region. A systematic review was conducted on the epidemiology of childhood hematologic cancers in Africa [14]. The study provided a comparison of pooled incidence rates amongst the different African regions from different studies and suggested an increase in haematological cancers in the African continent [14]. However, the report was only on haematological cancers and excluded other solid tumours.

The data reported by the WHO/IARC on the burden of paediatric cancers is the most extensive so far [2, 15]. However, these figures have been disputed as being an under-estimation of the actual distribution in SSA [1]. Registration methods differ worldwide; furthermore, the availability of data sources, classification standards and data coverage differ depending on the socio-economic status in the world regions, thus influencing the incidence rates. Now more than ever, there is a need for further research and on the spectrum and distribution of paediatric cancers in the SSA and other low-income countries region so as to provide such organisations with high quality and comparable data. The importance of data on cancer cannot be overemphasised, as it provides an insight on the actions that are needed and groups in a population that should be prioritised [16]. Accurate epidemiological data on paediatric cancers will enable mobilisation of sufficient resources for proper screening, prevention and treatment of these cancers. This review study will identify existing research gaps for future research to influence policy implementation and to improve the availability of diagnosis and treatment of paediatric cancers in SSA.

Only studies focusing on childhood malignancies will be included. The age range for this study is 0–14 years as it is the commonly used age range in most paediatric disease studies. To minimise bias, there will be no language restriction in selecting the studies. Since the study is aimed at mapping the distribution of paediatric cancers, quantitative studies will be included and qualitative studies will be excluded.

It is anticipated that the results of this study will give a reflection of paediatric cancer burden, assessment and identification of risk factors associated with paediatric cancer in the SSA region. Furthermore evidence synthesized from this study will help researchers and local decision makers in improving the perfomance of health systems, thus improving treatment and survival of children living with cancer.