Association Between Educational Level and Risk of Cancer in HIV-infected Individuals and the Background Population: Population-based Cohort Study 1995-2011

BACKGROUND: Human immunodeficiency virus (HIV)-infected individuals have increased risk of cancer. To our knowledge, no previous study has examined the impact of socioeconomic position on risk and prognosis of cancer in HIV infection.

METHODS: Population-based cohort-study, including HIV-infected individuals diagnosed (without intravenous drug abuse or hepatitis C infection) (n = 3205), and a background population cohort matched by age, gender, and country of birth (n = 22 435) were analyzed. Educational level (low or high) and cancer events were identified in Danish national registers. Cumulative incidences, incidence rate ratios (IRRs), and survival using Kaplan-Meier methods were estimated.

RESULTS: Low educational level was associated with increased risk of cancer among HIV-infected individuals compared to population controls: all (adjusted-IRRs: 1.4 [95% confidence interval {CI}, 1.1-1.7] vs 1.1 [95% CI, .9-1.2]), tobacco- and alcohol-related (2.1 [95% CI, 1.3-3.4] vs 1.3 [95% CI, 1.1-1.6]), and other (1.7 [95% CI, 1.1-2.8] vs 0.9 [95% CI, .7-1.0]). Educational level was not associated with infection-related or ill-defined cancers. One-year-survival was not associated with educational level, but HIV-infected individuals with low educational level had lower 5-year-survival following infection-related and ill-defined cancers.

CONCLUSIONS: Education is associated with risk and prognosis of some cancers in HIV infection, and diverges from what is observed in the background population.