March 4, 2009
Since the availability of potent HIV therapy, cancers not related to AIDS have become more common than AIDS-defining cancers among people with HIV. This is particularly true of cancers with a known infectious cause, such as anal and cervical cancers (caused by the human papillomavirus or HPV), liver cancer (caused by the hepatitis B and C viruses), and Hodgkin's disease (caused by the Epstein-Barr virus). Cancers without an infectious cause, particularly lung and skin cancers, are more common among people with HIV compared to people not living with HIV.
The use of potent HIV therapy impacts the development of infection-related cancers. In a study of over 20,000 people living with HIV in the Kaiser California system, the rate of anal cancer significantly declined once more potent therapies became widely available. A smaller decline in the rate of Hodgkin's disease was seen over this same period.
However, this same decline was not seen among more than 200,000 HIV-negative people of similar age, race and ethnicity over the same time frame-suggesting that the lower rates of cancer are likely due to the wider use and availability of potent HIV therapy and the resulting improvements in immune health. This same anti-cancer impact from taking HIV therapy was not seen in liver cancer.
Among the cancers not believed to be caused by an infectious agent, lung, skin and kidney cancers were higher among people living with HIV compared to their HIV-negative counterparts. Interestingly, HIV-positive men seemed to have a lower risk of prostate cancer than HIV-negative men of the same age, race and ethnicity over the 11-year study. There's some evidence that colorectal cancers may be increasing in people living with HIV in later years. The wider availability of HIV therapy did not make impact the risk of developing these cancers.
This preliminary report helps to further define cancers of concern for more focused research in HIV. Also, stronger immune systems due to HIV therapy may prevent the development of certain infection-related cancers, notably cervical/anal cancers and Hodgkin's disease. In addition to routine monitoring of HIV disease, people living with HIV should diligently explore their cancer risks and screen appropriately.