ArticlesCancer risk in adolescents and young adults living with HIV in South Africa: a nationwide cohort study
Introduction
Adolescents and young adults (AYA; aged 15–24 years) in South Africa are disproportionally affected by HIV. In 2020, one in three new HIV infections in South Africa occurred in people in this age group.1 Girls and young women are particularly vulnerable, accounting for an estimated 61 000 (80%) of 79 000 new HIV infections in this age group.1 Compared with other age groups, AYA living with HIV are less likely to initiate antiretroviral therapy (ART) and more likely to drop out of care and have poorly controlled HIV infection with higher rates of virological failure.2, 3
HIV-induced immunodeficiency combined with a higher susceptibility to oncogenic viruses increases the risk of cancer in people living with HIV.4 Cancer is rare in AYA, but an elevated cancer risk has been documented in those living with HIV, with the AIDS-defining cancers, Kaposi sarcoma and non-Hodgkin lymphoma, being the most frequently diagnosed.5 However, analyses of cancer incidence and associated risk factors in this age group are often limited by small numbers of cancer cases.5 Furthermore, data from sub-Saharan Africa, where most AYA living with HIV reside, are scarce.
The South African HIV Cancer Match (SAM) study is a nationwide cohort of people living with HIV in South Africa. We linked HIV-related laboratory records from the National Health Laboratory Services (NHLS) to cancer records from the National Cancer Registry (NCR) to create this cohort.6 The SAM study provided us with a unique data source to assess the incidence and spectrum of cancers in AYA living with HIV in South Africa.
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Study design and population
This nationwide cohort study was designed using data from the NHLS, the largest diagnostic pathology service in South Africa, and the pathology-based NCR from 2004 to 2014, as described in detail elsewhere.6 The NHLS serves the public sector through laboratories in all nine South African provinces and stores data at a corporate data warehouse. The NHLS is estimated to provide diagnostic pathology services to approximately 80% of the South African population. The NCR was established in 1986 and
Results
We included 782 454 AYA living with HIV over a study period of 11 years (appendix p 1): 176 019 (22·5%) were diagnosed with HIV between the ages of 15 and 19 years and 606 435 (77·5%) were diagnosed between the ages of 20 and 24 years. 698 066 (89·2%) of the included AYA living with HIV were women (table 1). The median time between the first and second HIV-related laboratory measurement was 230 days (IQR 99–533). The median CD4 count at baseline was 386 cells per μL (IQR 253–548) in the 15–19
Discussion
Kaposi sarcoma and non-Hodgkin lymphoma were the most frequent cancers in AYA living with HIV in South Africa. The overall risk of developing cancer increased slightly with age and was higher in male than female AYA living with HIV. Lower CD4 cell counts at baseline were associated with an elevated risk of Kaposi sarcoma, cervical cancer, non-Hodgkin lymphoma, and Hodgkin lymphoma after adjusting for sex and baseline calendar period.
In 2020, the most common cancer types in AYA worldwide were
Data sharing
The data underlying this Article will be shared on reasonable request to the corresponding author, subject to approval by the SAM cohort scientific committee.
Declaration of interests
We declare no competing interests.
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