Scanning electromicrograph of an HIV-infected T cell. Credit: NIAID

Deferred antiretroviral therapy (ART) initiation in ART-naive, HIV-positive persons is associated with a small increase in risk for AIDS-defining cancer. These findings add to the evidence that early ART may reduce risk for non-AIDS-defining cancer. A multinational prospective cohort study is published in Annals of Internal Medicine.

Immediate initiation ART regardless of CD4 cell count has been recommended in all HIV-positive persons since 2015. However, only about half of HIV-positive persons in non-resource-limited settings continue to initiate ART when their CD4 count decreases below 500 cells/L, primarily because of late diagnosis. Incidence of non-AIDS-related and AIDS-related cancer is increasing in HIV-positive persons for a number of reasons and is now a leading cause of death in HIV infection. It is unclear to what extent delayed ART initiation, with its consequences of continued HIV replication and immune deterioration, contributes to the .

Researchers from University Hospital Basel and University of Basel, Basel, Switzerland studied data from D:A:D (Data collection on Adverse events of anti-HIV Drugs), a large observational database that included data from HIV-positive persons from Europe, Australia, and the United States, to estimate the 10-year risk difference for non-AIDS-defined and AIDS-defined cancer with two different ART initiation strategies—immediate or deferred. After adjusting for baseline and time-dependent confounders (CD4 cell count and viral load), the researchers found that the 10-year absolute risk of non-AIDS-defining cancer was slightly lower in the immediate ART group compared to the deferred treatment group. Strategies promoting deferral were associated with a small increase in risk for AIDS-defining cancer. More research is needed to determine the effect of early art on non-AIDS-defining cancer.

More information: Annals of Internal Medicine (2021).

Journal information: Annals of Internal Medicine