Antiretroviral therapy reduces some cancer risks in people living with HIV, Texas study finds

In people living with HIV, antiretroviral therapy (ART) was associated with a reduced risk of not only AIDS-defining cancers, but also some non-AIDS defining cancers such as anal and liver cancer, according to a real-world study conducted in Texas. The study centered around the 2008-2015 time period, largely prior to the widespread acceptance of ART initiation at any CD4 count.

About This Study

“Real-world use of antiretroviral therapy and risk of cancer among people living with HIV in Texas” was published online on Oct. 27, 2023, in AIDS. The lead author is Marie-Josephe Horner, Ph.D., M.S.P.H., of the Division of Cancer Epidemiology and Genetics at the National Cancer Institute in Bethesda, Maryland.

Key Research Findings

Researchers linked HIV and cancer registries with each other and with a prescription claims database to determine the association between cancer incidence and HIV treatment. Data covered 63,694 people living with HIV (PLWH) in Texas who were followed for 276,804 person-years between 2008-2015. The model assumed perfect adherence and no drugs obtained outside the claims database. Before 2015, US treatment guidelines recommended starting ART only at CD4 counts <350 cells/mm³.

Fifty-one percent of participants were diagnosed with AIDS before or during the study period, and 2,137 participants were diagnosed with cancer during the study period. The most common cancers were non-Hodgkin lymphoma (388 participants), Kaposi’s sarcoma (244 participants), lung cancer (192 participants), and anal cancer (187 participants).

Assuming that participants who started ART remained on treatment, ART was associated with a significantly reduced risk of the two AIDS-defining cancers above, as well as anal cancer but not lung cancer. Taking ART was also associated with a lower risk of liver, but not cervical, cancer.

Overall, a median of 21% of days was covered by ART prescriptions, with a large proportion of participants having unknown treatment exposure due to gaps in prescriptions, or partial or non-recommended regimens. Considering only person-days with known ART coverage, participants had antiretroviral prescriptions for 55% of days during the follow-up period.

Discussion Highlights and Implications for Practice

Study limitations included the reliance on prescription data that may not reflect actual adherence and lack of information on antiretrovirals distributed under a program for un-/underinsured PLWH that covered 1 in 5 PLWH in the state in 2015.

Cancer risk remains elevated among PLWH compared to the general population. Removing barriers to ART adherence could help reduce that risk.

By Barbara Jungwirth