Objective: HIV-infected people are at increased risk of cancers of infectious origin. We estimated the burden of cancer attributable to infections among HIV-infected people in the United States in 2008.
Design: Incidence rates for cancer sites associated with infections were estimated from record linkage between HIV/AIDS registries and cancer registries.
Methods: Rates were applied to estimates of the population living with diagnosed HIV in the United States in 2008 to obtain the number of incident cancer cases. Site-specific attributable fractions and corresponding 95% confidence intervals (CIs) were estimated from infection prevalence among cancer cases. Infection prevalence data were derived from literature review of case series.
Results: Of an estimated 6200 incident cancer cases (95% CI 6000-6500), 2500 (95% CI 2400-2700) were attributable to infection (attributable fraction = 40%, 95% CI 39-42). The most important infections were Kaposi sarcoma herpes virus, Epstein-Barr virus, and human papillomavirus, which together were responsible for 2200 new cancer cases (95% CI 2100-2400), mainly Kaposi sarcoma, lymphomas, and ano-genital cancers. The attributable fraction in HIV-infected people was highest in the age group 20-29 years (69%, 95% CI 65-72). MSM were the HIV transmission group with the highest attributable fraction (48%, 95% CI 46-50), due to the high incidence of both Kaposi sarcoma and anal cancer.
Conclusion: The very high fraction of cancer attributable to infection in HIV-infected people points to special opportunities to prevent these cancers, that is, avoidance, detection, and early treatment of cancer-associated infections, and universal early detection and uninterrupted treatment of HIV infection to avoid immunosuppression.