People with HIV who go on antiretroviral treatment and maintain a fully suppressed viral load over the course of many years greatly mitigate their risk of cancer. However, such long-term viral suppression does not eliminate the disparity in cancer risk between those with and without HIV.

Publishing their findings in the Annals of Internal Medicine, researchers studied 1999 to 2015 Veterans Affairs data on 42,441 HIV-positive veterans (who were followed for a median 7.4 years) along with data on 104,712 demographically matched HIV-negative veterans (who were followed for a median 10.1 years).

A total of 3,821 of the HIV-positive veterans were diagnosed with 4,169 cases of cancer during the study period, including 616 AIDS-defining cancers, 817 virus-related non-AIDS-defining cancers (NADCs), 2,683 non-virus-related NADCs and 53 cancers that were poorly specified. A total of 7,163 of the HIV-negative individuals developed 7,879 cases of cancer, including 223 AIDS-defining cancers, 715 virus-related NADCs and 6,850 non-virus-related NDACs.

Of the cumulative 343,150 years that the HIV-positive cohort was followed, 22 percent of those years included participants living with unsuppressed HIV, 27 percent included participants living with early suppression of HIV (defined as the initial period of up to two years of having a fully suppressed viral load), 37 percent included participants living with long-term suppression of the virus (defined as the period following the first two years of having a fully suppressed viral load) and 14 percent included participants living with an unknown viral suppression status.

Sixty-two percent of the HIV-positive individuals achieved long-term viral suppression at some point during follow-up, doing so for a median 3.0 years.

The researchers adjusted the cancer data to account for demographics and cancer risk factors. They found that compared with HIV-negative individuals, the adjusted cancer rate was 2.35-fold higher while the HIV-positive individuals had unsuppressed HIV, 1.99-fold higher during the period of early viral suppression and 1.52-fold higher during the period of long-term viral suppression. Looking at AIDS-defining cancers, the researchers found that compared with HIV-negative individuals, the adjusted cancer rates among the three groups of HIV-positive individuals was a respective 22.73-fold, 9.48-fold and 2.22-fold higher. For virus-related NADCs, the cancer rates were a respective 3.82-fold, 3.42-fold and 3.17-fold higher. For non-virus-related NADCs, the relative cancer rates were a respective 1.4-fold, 1.53-fold and 1.32-fold higher.

In other words, long-term suppression of HIV lowers the risk of AIDS-defining cancers more than it lowers the risk of NADCs.

To read the study abstract, click here.