January 5, 2010
People with HIV may be at an increased risk of developing non-AIDS-defining cancers, suggests a new meta-analysis of 18 studies. Many of the cancers were related to infections and smoking, noted Dr. Meredith S. Shiels of the Johns Hopkins Bloomberg School of Public Health and colleagues.
Among the 625,716 HIV-positive individuals involved in the studies, there were 4,797 non-AIDS cancers. Standardized incidence ratios (SIRs) were elevated compared with the general population, including an SIR of 28 for anal cancer, 5.6 for liver cancer, and 11 for Hodgkin lymphoma. Elevated rates for cancers associated with smoking included an SIR of 2.6 for lung cancer, 1.7 for kidney cancer, and 1.5 for laryngeal cancer.
Among individuals who also had AIDS, Shiels and colleagues found a "dramatically" increased risk of leukemia and brain cancer (SIRs of 8.02 and 4.86, respectively). The risk of Hodgkin lymphoma and lung cancer was three times higher among AIDS patients than those whose infection had not progressed to AIDS. The risks of liver and laryngeal cancer were also elevated, and AIDS was associated with greater SIRs for all non-AIDS cancers combined.
"An association with advanced immune suppression was suggested for certain cancers," the authors concluded. "It remains unclear whether HIV-infected individuals are truly at greater risk for non-AIDS-defining cancers, or if confounding by unadjusted cancer risk factors may be responsible for the apparent elevated incidence," they wrote. "Future pooling projects (rather than meta-analyses) that compare HIV-infected individuals to HIV-uninfected individuals will be better able to elucidate the effect of HIV infection on the development of non-AIDS cancers."
The full study, "A Meta-Analysis of the Incidence of Non-AIDS Cancers in HIV-Infected Individuals," was published in the Journal of Acquired Immune Deficiency Syndromes (2009;52(5):611-622).