Burden of Kaposi sarcoma according to HIV status: A systematic review and global analysis

In 2020, over 34 000 cases of Kaposi sarcoma (KS) were estimated globally, all attributable to KS herpesvirus (KSHV). Prior to the HIV epidemic, KS already existed in KSHV endemic regions, notably in sub‐Saharan Africa (SSA). The HIV epidemic has vastly increased the KS burden. We developed a methodology to provide global estimates of KS burden according to HIV status. A systematic review identified studies reporting HIV prevalence in consecutive KS series. Pooled estimates of HIV prevalence, by country or UN subregion, were used to calculate population‐attributable fraction (PAF) and these were applied to IARC's GLOBOCAN 2020 to estimate burden and incidence of HIV‐attributable and non‐HIV‐attributable KS. We identified 55 eligible studies, reporting HIV prevalence ranging from ≤5% to ≥95%. Approximately 80% of KS in SSA was estimated attributable to HIV, vs ~50% in the rest of the world. By applying PAFs to national GLOBOCAN estimates, an estimated 19 560 KS cases attributable to HIV were diagnosed in SSA in 2020 (~80% of the worldwide burden), vs 5064 cases of non‐HIV‐attributable KS (~60% of the worldwide burden). Incidence of HIV‐attributable KS was highest in Southern Africa (6.0 cases per 100 000) and Eastern Africa (3.4), which were also the world regions with highest incidence of non‐HIV‐attributable KS (0.4 and 1.0 cases per 100 000, respectively). This first systematic effort to produce a global picture of KS burden stratified by HIV status highlights the continuing important burden of HIV‐attributable KS in SSA, even in the era of combined antiretroviral therapy. What's new? Before the HIV/AIDS epidemic, Kaposi sarcoma (KS) was rare in most regions of the world. With HIV's emergence, however, KS incidence increased dramatically. In this systematic review, approximately three‐quarters of KS cases globally were linked to HIV, even in the era of combination antiretroviral therapy (cART). Moreover, existing geographical disparities in KS burden were intensified by the HIV/AIDS epidemic, with notable impacts on sub‐Saharan Africa, where the majority of HIV‐attributable KS cases occurred in 2020. Overall, Southern and Eastern Africa had the highest rates of non‐HIV‐attributable and HIV‐attributable KS worldwide, offering insight into global KS burden according to HIV status.