Incidence of non-AIDS-defining cancer in antiretroviral treatment-naïve subjects after antiretroviral treatment initiation: an ACTG longitudinal linked randomized trials analysis.

Background: Prospective data on factors associated with the non-AIDS-defining cancer (NADC) incidence in HIV-infected individuals are limited.

Methods: We examined the NADC incidence in 3,158 antiretroviral treatment (ART)-naïve subjects after ART initiation in AIDS Clinical Trials Group trials; extended follow-up was available for 2,122 subjects. Poisson regression was used to examine the associations between covariates and incident NADC.

Results: At ART initiation, subjects (median age 37 years) were 40% non-Hispanic whites, and 82% were male; 23% had CD4+ T cell count ≤ 50 cells/mm³ and 25% had CD4 >350 cells/mm³. Median follow-up was 3.8 years. Among 64 incident NADCs, the most common were 8 anal cancers, 8 basal cell carcinomas, 8 Hodgkin's disease, and 6 lung cancers. In univariate models, age, smoking and recent (time-updated) CD4 were associated with incident NADC. There was no association between initial ART drug class (protease inhibitor, nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor) and NADC. After adjusting for age, race and sex: smoking [relative risk = 2.12 (95% CI = 1.1-4.08)] and recent CD4 (≤ 50 cells/mm³: 3.58, 1.22-10.45; 51-200 cells/mm³: 2.54, 1.30-5.0; 201-350 cells/mm³: 2.37, 1.32-4.26 vs. >350 cells/mm³) were associated with NADC.

Conclusion: Smoking and lower recent CD4 levels, but not initial ART drug class, were associated with NADC. Strategies for maintaining higher CD4 cell counts and successful smoking cessation may reduce the NADC incidence in the HIV-infected population.