Abstract Body

Background: The incidence of AIDS- and non AIDS-defining cancers in HIV-infected children and the impact of ART has not been evaluated in sub-Saharan Africa. We examined the incidence of cancer in HIV-infected children enrolled in antiretroviral therapy (ART) programmes in South Africa, using record linkage techniques.

Methods: We linked records of patients aged ≤16 years from five ART programmes (Harriet Shezi and Rahima Moosa in Johannesburg; Khayelitsha, Red Cross and Tygerberg in Cape Town) to the records of the four corresponding paediatric oncology units (Baragwanath and Charlotte Maxeke in Johannesburg; Red Cross and Tygerberg in Cape Town). Records were linked based on folder numbers, names, birth date and sex. Missing CD4 cell counts and percentages were multiply imputed. We calculated incidence rates and hazard ratios (HR) from Cox regression models including ART, sex, age, and immunodeficiency.

Results: Data of 11,707 HIV-infected children (29,348 person-years [pys]) were included in the analysis. Median age at enrolment was 6 years in children developing and 2.5 years in children not developing cancer. We identified 24 incident cancer cases, for an incidence rate of 82/100,000 pys (95% CI 55-122). Kaposi Sarcoma and Non Hodgkin Lymphoma were the most frequent cancers with incidence rates of 34 and 31/100,000 pys, respectively. There were few non AIDS-defining malignancies. In multivariate analysis, children on ART had a lower risk of developing cancer compared to children not on ART. The risk of developing cancer increased with age and more advanced immunodeficiency (Table). In children with cancer, one year survival was 73% (95% CI 61-82%).

Conclusions: ART reduces the risk of developing cancer in HIV-infected children in South Africa. Early linkage to care and early start of ART may help to further reduce the burden of cancer in these children.

    Univariable analyses Multivariable analyses
    HR (95% CI) HR (95% CI)
ART Not on ART 1 1
  On ART 0.43 (0.15-1.22) 0.28 (0.09-0.85)
Gender Male 1 1
  Female 0.74 (0.33-1.67) 0.71 (0.31-1.61)
Age < 3 years 1 1
  3 to 5 2.99 (0.66 – 13.61) 2.91 (0.64 – 13.25)
  5 to 10 5.38 (1.64 – 17.65) 5.59 (1.71 – 18.35)
  > 10 years 8.30 (2.21 – 31.22) 8.69 (2.30 – 32.80)
Immunodeficiency None/mild 1 1
  Advanced/severe 1.87 (0.40 – 8.72) 3.69 (1.11 – 12.29)

HR: hazard ratio, ART: antiretroviral therapy; CI: confidence interval