Risk of non-AIDS cancer higher for individuals infected with HIV

Nov 18 2008

The risk of non-AIDS cancer is higher for individuals infected with HIV than for the general population, according to a meta-analysis presented here at the American Association for Cancer Research's Seventh Annual International Conference on Frontiers in Cancer Prevention Research.

Compared with the general population, the risk for non-AIDS cancers was 2.3 times higher for men with HIV and 1.5 times greater for women with HIV. Among individuals with HIV, however, incidence rates were similar for those with AIDS and those without, relative to the general population.

Although the researchers did not examine why non-AIDS cancers may occur at a greater rate among individuals with HIV, clinicians should be aware of this potential increased risk when examining patients with HIV, said Meredith Shiels, M.H.S., an epidemiologist at Johns Hopkins School of Public Health.

"In particular, clinicians of HIV-infected patients should inquire about well-known modifiable cancer risk factors," she said. "For example, the prevalence of cigarette smoking, which is a cause of many types of cancer, is known to be higher among HIV-infected individuals."

Modern drug therapy has led to a longer life for patients with HIV. Because cancer risk increases with age, investigating the risk of cancer among patients with HIV is important. Although some cancers are known to be associated with HIV, such as Kaposi's sarcoma, non-Hodgkin's lymphoma and cervical cancer, limited research has been conducted on risk of non-AIDS cancers.

Shiels and her colleagues analyzed data from 11 U.S. and international studies comparing cancer incidence in individuals with HIV with the general population. Individual studies were excluded if they included data that overlapped with more recent studies. The meta-analysis combined standardized incidence ratios from each study and examined whether they differed by gender and prior AIDS diagnosis.

"We observed an overall elevated risk for all non-AIDS cancers combined among HIV-infected individuals compared with the general population," Shiels said. "The elevated risk appears to be greater among men than women."

Relative to the general population, the incidence of non-AIDS cancer appeared higher for individuals with and without an AIDS diagnosis. When the researchers adjusted the data for gender and study design, the estimates were similar: the risk of non-AIDS cancer was about two times greater than the general population for HIV-infected individuals both with and without AIDS.

When managing patients with HIV, clinicians should be aware of the potential for increased risk of non-AIDS related cancers. It is important for regular cancer screening to take place and for clinicians to encourage patients to modify factors that could affect cancer risk, such as cigarette use and nutrition.

The meta-analysis did not investigate possible reasons for the increased risk of non-AIDS cancers among patients with HIV. Understanding the link may lead to better management of cancer among patients with HIV and could be a topic for future study.