Trends in the incidence of cancers related to HIV-AIDS in Harare, Zimbabwe 1990-2019.

HIV prevalence in Harare reached a maximum of around 33% of adults in 1995, before falling to 12% in 2019. We examine trends in the incidence of Kaposi sarcoma (KS), non-Hodgkin lymphoma (NHL), Hodgkin lymphoma, and squamous cell conjunctival cancers (SCCCs) in the population of Harare in relation to changes in HIV prevalence, and the increasing availability and use of antiretroviral therapy (ART). Data from the population-based cancer registry of Harare are used to calculate incidence rates for the Black (African) population for the years 1990-2019. Incidence of KS increased to a peak in the late 1990s, after which rates declined, especially at younger ages. Mean age at diagnosis increased by about 8 years in men and 6 years in women. SCCC shows a similar trend to that of KS, with a dramatic 10-fold increase in incidence, followed by an equivalent fall. Although Hodgkin lymphoma showed no change in incidence over the 30-year period, rates of NHL progressively increased. Incidence in younger adults (aged younger than 44) stabilized after about 2001 but continued to increase in older individuals. The availability of high-quality cancer registry data over a long period has provided a unique opportunity to study the effects of the epidemic of HIV-AIDs and of ART availability on the risk of cancer in an African population. As HIV prevalence fell and ART coverage expanded, incidence of KS and SCCC declined, whereas for NHL the trends suggest that long-term infection with HIV may pose an increased risk, despite ART.