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.

Outcomes of Wilms tumor therapy in Lilongwe, Malawi, 2016-2021: Successes and ongoing research priorities.

INTRODUCTION: Wilms tumor therapy in low- and middle-income countries (LMICs) relies on treatment protocols adapted to resource limitations, but these protocols have rarely been evaluated in real-world settings. Such evaluations are necessary to identify high-impact research priorities for clinical and implementation trials in LMICs. The purpose of this study was to identify highest priority targets for future clinical and implementation trials in sub-Saharan Africa by assessing outcomes of a resource-adapted treatment protocol in Malawi. METHODS: We conducted a retrospective cohort study of children treated for Wilms tumor with an adapted SIOP-backbone protocol in Lilongwe, Malawi between 2016 and 2021. Survival analysis assessed variables associated with poor outcome with high potential for future research and intervention. RESULTS: We identified 136 patients, most commonly with stage III (n = 35; 25.7%) or IV disease (n = 35; 25.7%). Two-year event-free survival (EFS) was 54% for stage I/II, 51% for stage III, and 13% for stage IV. A single patient with stage V disease survived to 1 year. Treatment abandonment occurred in 36 (26.5%) patients. Radiotherapy was indicated for 55 (40.4%), among whom three received it. Of these 55 patients, 2-year EFS was 31%. Of 14 patients with persistent metastatic pulmonary disease at the time of nephrectomy, none survived to 2 years. Notable variables independently associated with survival were severe acute malnutrition (hazard ratio [HR]: 1.9), increasing tumor stage (HR: 1.5), and vena cava involvement (HR: 3.1). CONCLUSION: High-impact targets for clinical and implementation trials in low-resource settings include treatment abandonment, late presentation, and approaches optimized for healthcare systems with persistently unavailable radiotherapy.

Rapid gene fusion testing using the NanoString nCounter platform to improve pediatric leukemia diagnoses in Sub-Saharan Africa.

Risk stratification and molecular targeting have been key to increasing cure rates for pediatric cancers in high-income countries. In contrast, precise diagnosis in low-resource settings is hindered by insufficient pathology infrastructure. The Global HOPE program aims to improve outcomes for pediatric cancer in Sub-Saharan Africa (SSA) by building local clinical care and diagnostic capacity. This study aimed to assess the feasibility of implementing molecular assays to improve leukemia diagnoses in SSA. Custom NanoString nCounter gene fusion assays, previously validated in the US, were used to test samples from suspected leukemia patients. The NanoString platform was chosen due to relatively low cost, minimal technical and bioinformatics expertise required, ability to test sub-optimal RNA, and rapid turnaround time. Fusion results were analyzed blindly, then compared to morphology and flow cytometry results. Of 117 leukemia samples, 74 were fusion-positive, 30 were negative, 7 were not interpretable, and 6 failed RNA quality. Nine additional samples were negative for leukemia by flow cytometry and negative for gene fusions. All 74 gene fusions aligned with the immunophenotype determined by flow cytometry. Fourteen samples had additional information available to further confirm the accuracy of the gene fusion results. The testing provided a more precise diagnosis in >60% of cases, and 9 cases were identified that could be treated with an available tyrosine kinase inhibitor, if detected at diagnosis. As risk-stratified and targeted therapies become more available in SSA, implementing this testing in real-time will enable the treatment of pediatric cancer to move toward incorporating risk stratification for optimized therapy.

Pediatric HIV+ Kaposi sarcoma exhibits clinical, virological, and molecular features different from the adult disease.

BACKGROUNDKaposi sarcoma (KS) is among the most common childhood cancers in Eastern and Central Africa. Pediatric KS has a distinctive clinical presentation compared with adult KS, which includes a tendency for primary lymph node involvement, a considerable proportion of patients lacking cutaneous lesions, and a potential for fulminant disease. The molecular mechanisms or correlates for these disease features are unknown.METHODSThis was a cross-sectional study. All cases were confirmed by IHC for KS-associated herpesvirus (KSHV) LANA protein. Baseline blood samples were profiled for HIV and KSHV genome copy numbers by qPCR and secreted cytokines by ELISA. Biopsies were characterized for viral and human transcription, and KSHV genomes were determined when possible.RESULTSSeventy participants with pediatric KS were enrolled between June 2013 and August 2019 in Malawi and compared with adult patients with KS. They exhibited high KSHV genome copy numbers and IL-6/IL-10 levels. Four biopsies (16%) had a viral transcription pattern consistent with lytic viral replication.CONCLUSIONThe unique features of pediatric KS may contribute to the specific clinical manifestations and may direct future treatment options.FUNDINGUS National Institutes of Health U54-CA-254569, PO1-CA019014, U54-CA254564, RO1-CA23958.