Incidence of Cancers Among Children Living With HIV in Malawi After Widespread Availability of Antiretroviral Therapy: A Population-Based Study.

Abstract

Few data describe the modern epidemiology of pediatric HIV-associated cancers in sub-Saharan Africa, home to over 80% of the world's children living with HIV. This study evaluated the incidence of cancers among these children over 15 years after widespread antiretroviral therapy (ART) adoption in Malawi. We conducted a retrospective population-based cohort study leveraging multiple independent data sources comprehensive of all cancer diagnoses among children living with HIV in Northern and Central Malawi between 2010 and 2024. HIV-associated cancers were defined as those cancers with well-established epidemiologic associations with HIV. Cumulative incidence and average annual percent change were estimated using joinpoint regression. Next, we conducted a subcohort analysis within the country's largest pediatric HIV clinic to evaluate cancer risk factors using log-binomial regression. Among 1,686 pediatric cancer diagnoses, 184 (10.9%) occurred in children with HIV. Kaposi sarcoma (KS) accounted for 96% of cases. The cumulative incidence of HIV-associated malignancies fell from 4.7 cases per million children in 2010 to 1.2 per million in 2024, representing an 84% decline from its peak in 2013 and an average annual percent decline of 13% (<i>P</i> < .001). KS dropped from the third- to seventh-most common childhood cancer in the region. Notably, 58% of affected children were ART-naïve at diagnosis. Initiating ART in infancy reduced the risk of KS by 69% (<i>P</i> < .001). Other HIV-associated cancers were rare, comprising 0.4% of all cases diagnosed. National ART expansion substantially reduced pediatric HIV-associated cancers in Malawi, achieving declines comparable with those seen in high-income countries. Sustained early diagnosis and ART linkage remain essential to sustain progress.