Navigating the Accelerated Epidemiological Transition in South Africa: The Impact of the Increasing Multimorbidity and Evolving HIV Landscape on Cancer Trends
Description: Background: Sub-Saharan Africa is undergoing a rapid epidemiological transition, facing a double burden of infectious diseases like HIV and emerging non-communicable diseases including cancer and diabetes. This double burden results in complex interactions creating additional health challenges in the region. Both HIV and diabetes increase the risk of developing certain cancer types. To date, the South African HIV Cancer Match (SAM) study, established with support from the Swiss National Science Foundation, has focused on cancer research among people with HIV (PWH). It is based on a linkage of laboratory records from the National Health Laboratory Services (NHLS) and cancer diagnoses from the National Cancer Registry (NCR) and includes data on >9 million PWH for 2004-2021. Expanding the SAM study to include diabetes-related laboratory records will provide a unique opportunity to investigate the impact of the epidemiological transition and coexisting HIV and diabetes epidemics on cancer trends in sub-Saharan Africa.Aims: As sub-Saharan Africa experiences an accelerated epidemiological transition, we aim to further strengthen the SAM study as a unique resource for cancer research in the region by expanding its scope. Specifically, we aim to 1) construct a new nationwide cohort of people living with diabetes and cancer outcomes in South Africa, 2) compare temporal trends of infection-related and infection-unrelated cancers among people with or without HIV, and 3) examine potential synergistic effects of HIV and diabetes mellitus on cancer risk in South Africa. Methods: The proposed research is organized in three work packages (WPs): WP1) SAM expansion: We will use state-of-the-art machine-learning based, probabilistic record linkage methods on diabetes-related laboratory records such as HbA1C and blood glucose from the NHLS to identify records belonging to the same person based on names, date of birth, sex, and facility. We will then probabilistically link this diabetes cohort to cancer diagnoses from the NCR. If individuals in the diabetes cohort cannot be linked to the SAM cohort, they will be assumed to be HIV-negative, while PWH in the current SAM cohort not linked to the diabetes cohort will be assumed to be free from diabetes. PWH in the current SAM cohort who can be linked to the new diabetes cohort will be assumed to live with both conditions. All linkages will be performed at the NCR located on the NHLS campus in Johannesburg, South Africa. WP2) Cancer trends in people with and without HIV: Using flexible parametric survival models, we will estimate the incidence rates of infection-related and infection-unrelated cancers among people with and without HIV as a function of calendar year, stratified by sex and age group. We will use Joinpoint models to identify temporal trends in age-standardized cancer rates by sex and HIV status. Among PWH, we will further examine temporal cancer trends by estimating the association of the population-level antiretroviral (ART) coverage on cancer rates using Poisson regression models, stratified by sex. ART coverage estimates for South Africa will be retrieved from the Thembisa model. WP3) Multimorbidity and cancer: We will examine the synergistic effect of both HIV and diabetes by comparing incidence rates of various infection-related and infection-unrelated cancers as a function of age among people living with both HIV and diabetes to those affected by one of these conditions only using flexible parametric survival models.Impact: The expanded SAM study will provide unique insights into cancer trends in sub-Saharan Africa, as the region faces both a high HIV prevalence and a rapidly increasing burden of non-communicable diseases including diabetes. The findings of the proposed project will be highly relevant for cancer control programs in South Africa and other low- and middle-income settings with a high HIV burden, experiencing an accelerated epidemiological transition.
Amount: CHF 690,700
Funding type: research
Funder scheme: Project funding
Start date: 2025-07-01
End date: 2029-06-30
Investigator: Rohner, Eliane
Institution: University of Berne – BE
Funded outputs count: 2
Funder award ID: 10004150
OpenAlex ID: G889131287