Early, sustained antiretroviral therapy (ART), which results in long-term viral suppression, helps to prevent Aids-defining cancers and also non-Aids-defining cancers, to a lesser degree. However, patients with long-term viral suppression still had excess cancer risk compared to uninfected patients.
The study is the first to examine the effects of prolonged periods of viral suppression and potential cancer prevention benefits for the aging population of persons living with HIV.
Persons with HIV are at increased risk for Aids-defining cancers (Kaposi sarcoma, non-Hodgkin lymphoma, invasive cervical cancer) and non-Aids-defining cancers (lung, larynx, melanoma, leukaemia, etc). Some of these cancers are known to be caused by viruses (certain anal, liver, Hodgkin lymphoma, etc) that are common among persons with HIV.
Viral suppression is a key component of HIV treatment, and studies have shown an association between prolonged viral suppression and decreased risk for some types of cancer. However, no studies have specifically focused on the effect of sustained viral suppression on overall cancer risk.
Researchers from the Stanford Centre for Population Health Sciences compared cancer rates for 42,441 HIV-positive veterans with those of 104,712 demographically-matched uninfected veterans from 1999-2015 to determine whether long-term viral suppression was associated with decreased cancer risk. They found that cancer risk was highest in the unsuppressed state, lower in early suppression, lower still in long-term suppression, and lowest in uninfected patients for all cancer, Aids-defining cancer, virus non-Aids-defining-cancer, and several cancer types.
According to the authors, these findings are helpful to both infectious disease and internal medicine clinicians who care for the population of aging HIV-positive patients. Understanding how HIV interacts with viral coinfections and results in higher risks of cancer may offer critical insight in how to better prevent and treat these cancers for everyone.
Background: Viral suppression is a primary marker of HIV treatment success. Persons with HIV are at increased risk for AIDS-defining cancer (ADC) and several types of non–AIDS-defining cancer (NADC), some of which are caused by oncogenic viruses.
Objective: To determine whether viral suppression is associated with decreased cancer risk.
Design: Prospective cohort.
Setting: Department of Veterans Affairs.
Participants: HIV-positive veterans (n = 42 441) and demographically matched uninfected veterans (n = 104 712) from 1999 to 2015.
Measurements: Standardized cancer incidence rates and Poisson regression rate ratios (RRs; HIV-positive vs. uninfected persons) by viral suppression status (unsuppressed: person-time with HIV RNA levels ≥500 copies/mL; early suppression: initial 2 years with HIV RNA levels <500 copies/mL; long-term suppression: person-time after early suppression with HIV RNA levels <500 copies/mL).
Results: Cancer incidence for HIV-positive versus uninfected persons was highest for unsuppressed persons (RR, 2.35 [95% CI, 2.19 to 2.51]), lower among persons with early suppression (RR, 1.99 [CI, 1.87 to 2.12]), and lowest among persons with long-term suppression (RR, 1.52 [CI, 1.44 to 1.61]). This trend was strongest for ADC (unsuppressed: RR, 22.73 [CI, 19.01 to 27.19]; early suppression: RR, 9.48 [CI, 7.78 to 11.55]; long-term suppression: RR, 2.22 [CI, 1.69 to 2.93]), much weaker for NADC caused by viruses (unsuppressed: RR, 3.82 [CI, 3.24 to 4.49]; early suppression: RR, 3.42 [CI, 2.95 to 3.97]; long-term suppression: RR, 3.17 [CI, 2.78 to 3.62]), and absent for NADC not caused by viruses.
Limitation: Lower viral suppression thresholds, duration of long-term suppression, and effects of CD4+ and CD8+ T-cell counts were not thoroughly evaluated.
Conclusion: Antiretroviral therapy resulting in long-term viral suppression may contribute to cancer prevention, to a greater degree for ADC than for NADC. Patients with long-term viral suppression still had excess cancer risk.
Lesley S Park, Janet P Tate, Keith Sigel, Sheldon T Brown, Kristina Crothers, Cynthia Gibert, Matthew Bidwell Goetz, David Rimland, Maria C Rodriguez-Barradas, Roger J Bedimo, Amy C Justice, Robert Dubrow