Cancer in HIV-positive and HIV-negative adolescents and young adults in South Africa: a cross-sectional study

Objective To determine the spectrum of cancers in AYAs living with HIV in South Africa compared to their HIV negative peers. Design Cross sectional study with cancer data provided by the National Cancer Registry and HIV data from the National Health Laboratory Service. Setting and participants The NHLS is the largest provider of pathology services in the South African public sector with an estimated coverage of 80%. The NCR is a division of the NHLS. We included AYAs (aged 10-24 years) diagnosed with cancer by public health sector laboratories between 2004 and 2014 (n=8 479). We included 3 672 in the complete case analysis. Primary and secondary outcomes We used linked NCR and NHLS data to determine the spectrum of cancers by HIV status in AYAs. We also used multivariable logistic regression to describe the association of cancer in AYAs with HIV, adjusting for age, sex (as appropriate), ethnicity, and calendar period. Due to the large proportion of unknown HIV status we also imputed (post-hoc) the missing HIV status. Results From 2004-2014, 8 479 AYAs were diagnosed with cancer, HIV status was known for only 45% (n=3812); of those whose status was known, about half were HIV positive (n=1853). AYAs living with HIV were more likely to have Kaposi’s sarcoma (adjusted odds ratio (aOR) 218, 95% CI 89.9-530), cervical cancer (aOR 2.18, 95% CI 1.23-3.89), non-Hodgkin’s lymphoma (aOR 2.12, 95% CI 1.69-2.66), and anogenital cancers other than cervix (aOR 2.73, 95% CI 1.27-5.86). About 44% (n=1 062) of AYAs with HIV related cancers had not been tested for HIV, though they were very likely to have the disease. Conclusions Cancer burden in AYAs living with HIV in South Africa could be reduced by screening young women for cervical cancer and vaccinating them against human papilloma virus (HPV) infection. Strength and limitations This is the first nationwide study in South Africa to compare the distribution of cancers in adolescents and young adults (AYAs) by HIV status. The record linkage and the additional results determined from the text mining process ensured that we extracted the maximum available HIV results. We assumed a CD4 count test indicates being HIV positive but CD4 testing maybe performed for other reasons Since this was a population of only AYAs diagnosed with cancer, the odds ratios could be overestimated or underestimated depending on the frequency of the cancer