Incidence rates of non-Hodgkin lymphoma subtypes among Black Africans with and without HIV in South Africa: a national registry-based study.

Abstract

Background: The impact of HIV on incident non-Hodgkin lymphoma (NHL) varies by subtype. We compared the incidence rates of NHL subtypes (aggressive and indolent) between Black Africans with and without HIV in South Africa from 2010 to 2021.

Methods: We identified incident NHL among children and adults from the South African National Cancer Registry and stratified yearly population by HIV status, sex, age group and health care sector. We applied Poisson regression models, adjusting for sex, age, and calendar period, to estimate adjusted incidence rate ratios (aIRRs) for NHL and its subtypes among Black Africans with and without HIV. We calculated aIRR stratified by calendar period, sex, and age group.

Findings: We identified 11,187 new NHL; 54% (n = 6023) occurred in male individuals. The risk of all NHL combined was higher among Black Africans with HIV than those without HIV, but the strength of the association varied by subtype. The aIRRs were highest for cutaneous T-cell lymphoma, diffuse large B-cell lymphoma and Burkitt lymphoma. There was no evidence that the strength of association changed over calendar period for most subtypes. The positive association with HIV was stronger among male individuals and those <45 years for all NHL combined and many subtypes.

Interpretation: In South Africa, incidence rates of all NHL subtypes are higher among Black Africans with HIV than those without HIV. Further context specific studies are needed to clarify the underlying mechanisms such as immune dysfunction, chronic inflammation, or oncogenic co-infections to inform early NHL diagnosis and timely treatment.

Funding: US National Institutes of Health, Swiss National Science Foundation and Swiss Cancer Research foundation.