Tumor-Associated Edema in Children with Kaposi Sarcoma: 14 Years' Experience at Kamuzu Central Hospital, Lilongwe, Malawi.

Abstract

Kaposi sarcoma (KS) is a common lymphatic endothelial cancer among children with and without HIV in central and eastern Africa. Despite its clinical heterogeneity, its various clinical phenotypes are often grouped together in staging and treatment algorithms. Patients with KS tumor-associated edema, referring to hard, non-pitting lesions which often lead to chronic disability, represent a unique, understudied subgroup of children with KS. To continue our work defining the distinct phenotypes of pediatric KS, this study aimed to assess the clinical progression and outcomes of KS edema in children. A retrospective cohort study was conducted at Kamuzu Central Hospital in Lilongwe, Malawi, focusing on children diagnosed with KS edema between 2010 and 2023. We identified 52 children with KS edema, representing 27% of all patients with KS. Initial chemotherapy resulted in a clinical response in 92% of patients, but 46% experienced relapse or disease progression with a median time to first relapse of 12 months. Multiple progressions were common, with 31% of patients experiencing two or more events. Event-free survival at two years was 32%, dropping to 24% at five years, while overall survival was 73% at two years and 57% at five years. Relapse was more common among patients with KS edema versus those without it (relative risk = 2.1; 95%CI, 1.4-3.2; p < 0.001). Eight patients (15%) relapsed with visceral disease, five of whom originally presented with KS edema alone. Patients with KS edema have a unique, relapsing-remitting pattern of disease with a high risk of relapse relative to other forms of KS with subsequent long-term mortality, even after initial positive treatment responses. Late relapse and mortality with visceral disease are possible even among children presenting initially with KS edema alone. Children with KS edema require long-term follow-up, and novel treatment approaches tailored towards preventing frequent relapse are needed.