A Prospective Cohort Study Identifies Two Types of HIV+ Kaposi Sarcoma Lesions: Proliferative and Inflammatory

Kaposi sarcoma (KS) is the most common cancer in people living with HIV (PLWH) in many countries where KS-associated herpesvirus is endemic. Treatment has changed little in 20 years, but the disease presentation has. This prospective cohort study enrolled 122 human immunodeficiency virus (HIV) positive KS patients between 2017 and 2019 in Malawi. Participants were treated with bleomycin, vincristine and combination antiretroviral therapy, the local standard of care. One-year overall survival was 61%, and progression-free survival was 58%. The 48-week complete response rate was 35%. RNAseq (n = 78) differentiated two types of KS lesions, those with marked endothelial characteristics and those enriched in inflammatory transcripts. This suggests that different KS lesions are in different disease states consistent with the known heterogeneous clinical response to treatment. In contrast to earlier cohorts, the plasma HIV viral load of KS patients in our study was highly variable. A total of 25% of participants had no detectable HIV; all had detectable KSHV viral load. Our study affirms that many KS cases today develop in PLWH with well-controlled HIV infection and that different KS lesions have differing molecular compositions. Further studies are needed to develop predictive biomarkers for this disease.