Incidence of Endemic Burkitt Lymphoma in Three Regions of Mozambique

Mosquito Bed Net Use and Burkitt Lymphoma Incidence in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Importance

Burkitt lymphoma (BL) is one of the most common childhood cancers in sub-Saharan Africa and is etiologically linked to malaria. However, evidence for an effect of malaria interventions on BL is limited.

Objective

To investigate the potential population-level association between large-scale rollout of insecticide-treated bed nets (ITNs) in sub-Saharan Africa in the 2000s and BL incidence.

Data Sources

In this systematic review and meta-analysis, a search was conducted in the Embase, Global Health, and Medline databases and in cancer registry publications between January 1, 1990, and February 27, 2023.

Study Selection

All epidemiologic studies on BL incidence rates in children and adolescents aged 0 to 15 years in sub-Saharan African countries where malaria is endemic were identified by 2 reviewers blinded to each other's decision.

Data Extraction and Synthesis

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. Data were extracted independently by 2 reviewers, and quality was scored based on 3 predefined criteria: data collection, case ascertainment, and calculation of person-time at risk.

Main Outcomes and Measures

Incidence rates of BL during childhood and mean ITN use in the population. Data were analyzed using a random-effects negative binomial regression model.

Results

Of 2333 studies meeting selection criteria, 23 comprising 66 data points on BL incidence were included based on 5226 BL cases from locations with large-scale ITN use in 17 countries. Rates of BL were 44% (95% CI, 12%-64%) lower in the period after ITN introduction compared with before. The adjusted pooled incidence rates of BL were 1.36 (95% CI, 0.88-2.10) and 0.76 (95% CI, 0.50-1.16) per 100 000 person-years before and after introduction of ITNs, respectively. After adjusting for potential confounders, a 1-percentage point increase in mean ITN use in the population in the 10 years before BL data collection was associated with a 2% (95% CI, 1%-4%) reduction in BL incidence.

Conclusions and Relevance

In this systematic review and meta-analysis, large-scale rollout of ITNs in the 2000s was associated with a reduction in BL burden among children in sub-Saharan Africa. Although published data may not be representative of all incidence rates across sub-Saharan Africa, this study highlights a potential additional benefit of malaria control programs.

Cancer in Mozambique: Results from two population-based cancer registries

Results from two recently established population-based registries in Mozambique are reported: Beira in the central region (2014-2017) and Maputo, the capital city, in the South (2015-2017). The results are compared to those from Maputo (Lourenço Marques at the time) in 1956-1960 (appearing Cancer Incidence in Five Continents Vol 1), and with estimated incidence rates from other regions of Africa. The elevated prevalence of HIV infection (12.6% of adults in 2018) results in high rates for HIV-related cancers, and the greater prevalence in central Mozambique, compared to the south, largely explains the rather higher rates of Kaposi sarcoma (males), non-Hodgkin lymphoma, squamous cell carcinoma of conjunctiva and cervical cancer in Beira than in Maputo. Burkitt lymphoma is the commonest childhood cancer in Beira, with high rates typical of East Africa, while the low rates in Maputo are more typical of Southern Africa. Overall, 44% of cancers in Maputo and 52% in Beira are estimated to be caused by infectious agents. In the last 60 years, cancers more frequent in developed countries, such as breast and prostate, are emerging in Mozambique. The incidence of the former in Maputo has increased fivefold since 1956-1960, that of prostate cancer 2.5-fold, and that of large bowel cancer doubled. The results reported here were used to make national estimates of incidence, mortality and prevalence in Globocan 2018. The two registries were important in providing data to establish priority actions in the National Cancer Control Plan, and are a valuable resource to monitor progress toward its goals.