Divergent clinical presentations and outcomes among children and adolescents with Kaposi sarcoma in Malawi and Tanzania.

Objectives: The Kaposi sarcoma (KS) T0 versus T1 staging classification does not address the unique clinical features of paediatric KS in human gammaherpesvirus 8 (HHV-8) endemic regions of Africa. This study seeks to define patterns of childhood KS using a paediatric-specific approach.

Methods: The Lilongwe paediatric KS staging classification categorizes disease based on clinical phenotype: stage 1 = mild/moderate KS limited to cutaneous/oral involvement, stage 2 = primarily lymphadenopathic disease, stage 3 = woody edema KS, stage 4 = visceral and/or severe/disseminated mucocutaneous disease. Characteristics and outcomes were evaluated from paediatric referral centres in Lilongwe, Malawi, and Mbeya, Tanzania.

Results: Among 171 patients, the median age was 9.3 years, 37% (n = 63) were female, and 87% (n = 149) had HIV. Breakdown by stage was as follows: 18% (n = 31) stage 1, 33% (n = 56) stage 2, 19% (n = 33) stage 3, and 30% (n = 51) stage 4. Age (younger stage 2 and older stage 3), severe CD4 count suppression (lower CD4 for stages 1 and 4), and presence of severe anaemia and thrombocytopenia (worse for stages 2 and 4) differed across stages. Estimated 2-year event-free survival/progression-free survival/overall survival by stage was as follows: stage 1, 81%/81%/87%; stage 2, 50%/50%/63%; stage 3, 24%/49%/81%; and stage 4, 29%/34%/54%. Sub-analysis of stage 2 lymphadenopathic KS demonstrated superior long-term 6-year event-free survival of 70% (95% confidence interval [CI] 49-83) for younger children (aged <7 years) versus 27% (95% CI 8-51) for older children.

Conclusions: This paediatric-specific staging classification categorizes patients with distinct characteristics and patterns of treatment response. This platform may guide clinicians to provide risk-stratified treatment with the hope of improving survival among children with KS.