Extracutaneous Kaposi sarcoma risk remains higher in people with HIV in the post-ART era: a nation-wide population-based study.

OBJECTIVE: To assess Kaposi sarcoma (KS) by HIV-status in Sweden 1983-2017, with particular focus on extracutaneous KS.

DESIGN: Population-based study linking the Total Population Registry, the Swedish HIV Registry InfCareHIV, and the Swedish Cancer Registry.

METHODS: We included all Swedish residents, born in or outside Sweden between 1940 and 2000 (n = 8 587 829), assessing the annual incidence of KS, adjusted hazard ratios (adjHR), and odds ratios (adjOR) in the pre- and post-combination antiretroviral therapy (ART) eras.

RESULTS: KS was found in 324 individuals of whom 202 (62%) were people living with HIV (PLHIV). While the incidence of KS decreased in PLHIV, it remained higher compared to HIV-negative at end of follow-up (28 vs. 0.09 per 100 000 person-years, p < 0.001). In the post ART era PLHIV still had an increased risk of both cutaneous (adjHR 616, 95% confidence interval [CI] 410-926) and extracutaneous KS (adjHR 2068, 95% CI 757-5654), compared to HIV-negative individuals, although there were no cases of extracutaneous disease among virally suppressed PLHIV. In the post-ART era, the relative risk for KS remained higher in men, particularly MSM, and viral suppression was associated with lower odds of KS (adjOR 0.05, 95% CI 0.03-0.09).

CONCLUSIONS: KS remained increased in PLHIV in the post-ART era, with a particularly high risk for extracutaneous disease compared to HIV-negative individuals. Notably, there were no cases of extracutaneous disease among virally suppressed PLHIV, suggesting a less aggressive disease in this population. Further studies on KS in virally suppressed PLHIV are warranted.