Long-term viral suppression from antiretroviral therapy (ART) may reduce the risk of both AIDS-defining cancer (ADC) and non-ADC (NADC) among patients with HIV, according to a study published in the Annals of Internal Medicine.1
Patients who are HIV positive are at increased risk of developing ADCs and NADCs from various oncogenic viruses, including Kaposi sarcoma-associated herpesvirus, Epstein-Barr virus, human papillomavirus, and hepatitis B/C viruses. Researchers hypothesized that ART, which suppresses viral load, improves immune function, and reduces inflammation, may lead to reduced cancer risk among this population.
For this prospective cohort study, researchers accessed the Veterans Aging Cohort Study (VACS) and matched 42,441 HIV-positive veterans with 104,712 uninfected veterans. Each HIV-positive person was classified as unsuppressed, early suppression, and long-term suppression. Cancer data was derived from the VA Central Cancer Registry and the VA Corporate Data Warehouse oncology registry; cancer types were grouped into all cancer, ADC, NADC caused by oncogenic viruses, NADC not caused by oncogenic viruses, and poorly specified cancers.
Among the 42,441 patients that were HIV-positive, 3821 developed 4169 cases of cancer, and of the 104,712 non-HIV-positive patients, 7163 developed 7879 cases of cancer. The median observation time was 7.4 and 10.1 years among patients that were HIV-positive and uninfected, respectively.
Results showed that the cancer incidence was highest among HIV-positive patients who were unsuppressed (relative risk [RR], 2.35; 95% CI, 2.19-2.51), followed by patients with early suppression (RR, 1.99; 95% CI, 1.87-2.12), and lowest among those who had long-term suppression (RR, 1.52; 95% CI, 1.44-1.61).
These correlations were strongly linked with patients who developed ADC (unsuppressed: RR, 22.73; early suppression: RR, 9.48; long-term suppression: RR, 2.22) and was much weaker for oncogenic viral NADC (unsuppressed: RR, 3.82; early suppression: RR, 3.42; long-term suppression: RR, 3.17). There were no associations between the viral suppression and the incidence of NADC not caused by viruses.
The authors concluded that the “… findings suggest that early, sustained ART, which results in long-term viral suppression, may contribute to cancer prevention, with a marked risk reduction for ADC, a much more modest reduction for virus NADC, and possible reductions for certain types of non-virus NADC. However, excess cancer risk remained among patients with long-term suppression.”
- Park LS, Tate JP, Sigel K, et al. Association of viral suppression with lower AIDS-defining and non-AIDS-defining cancer incidence in HIV-infected veterans [published online June 11, 2018]. Ann Intern Med. doi: 10.7326/M16-2094