US study reports relationship between non-AIDS-defining cancers and HIV virologic control, CD4 nadir/recovery

Regardless of a person’s viral load at the time they initiate antiretroviral treatment, the duration of their subsequent viral suppression is associated with a lower risk of developing a non-AIDS-defining cancer compared to those who experience poorer HIV control over time, a large U.S. study found. The study also noted that while CD4 nadir heavily affected viral cancer risk, that risk was attenuated by CD4 gains in the first 12 to 18 months of treatment.

About This Study

“The association of HIV control and immunosuppression with risk of non-AIDS defining cancer risk among patients on antiretroviral therapy” was published online on Nov. 16, 2023, in Journal of Acquired Immune Deficiency Syndromes. The lead author is Brittney L. Dickey, Ph.D., M.P.H., of the Center for Immunization and Infection Research in Cancer and the Department of Cancer Epidemiology at Moffitt Cancer Center in Tampa, Florida.

Key Research Findings

Researchers analyzed factors associated with developing a non-AIDS-defining cancer among 29,568 people in one of eight U.S. clinic-based cohorts. Participants began antiretroviral therapy between 1996 and 2016, and models were based on participants’ electronic health records. Most participants were men and around half of participants were Black.

Overall, there were 1,070 non-AIDS cancer diagnoses; of 623 diagnoses the researchers explored more fully, 410 were non-viral and 213 were viral. The most common cancers were anal (38% of viral cancers) and lung (25% of non-viral cancers).

A CD4 count below 200 cells/µL when starting HIV treatment was associated with an 80% higher risk of developing a viral cancer, but that risk fell as on-treatment CD4 counts rose: The risk of viral cancer dropped by 14% for each 100 cells/µL increase in CD4 count during the first 12 to 18 months of treatment. The risk of viral or non-viral non-AIDS cancer dropped the longer a participant spent with a CD4 count >500 cells/µL. Longer time virally suppressed (HIV viral load <50 copies/mL) was also associated with lower risk of both viral and non-viral cancers.

Discussion Highlights and Implications for Practice

Study limitations reported included a lack of tobacco use history for all participants, which can affect lung cancer risk, and small sample sizes for individual cancer sites, which precluded cancer-specific modeling.

Results show the importance of HIV control in preventing non-AIDS-defining cancers among people on antiretroviral treatment, including those with poor HIV markers at baseline, the authors commented. The researchers also noted that these findings support the rationale that a weakened immune system cannot clear oncogenic viruses, such as human papillomavirus, increasing the risk for anal and other cancers. Further research is needed into the relationship between HIV control and specific cancer sites, they said.

By Barbara Jungwirth