As pointed out by Eric Engels of the National Cancer Institute, who moderated the discussion and was a co-author of the study, HIV has long been linked to three AIDS-defining cancers – Kaposi’s Sarcoma (KS), non-Hodgkin’s lymphoma (NHL) and cervical cancer – the risks of which are greatly increased in people with HIV compared to the rest of the population. Another four cancers – Hodgkin’s lymphoma, anal cancer, lung cancer and liver cancer – are also found more commonly in people living with HIV than in the general population.
The relative contribution of these cancers to the overall burden of cancer in people with HIV has been changing, though. Since the era of antiretroviral therapy (ART), opportunistic infections and AIDS-related cancers have been decreasing in incidence – although NHL is still the most common cancer in people living with HIV. The trends for other HIV-associated cancers have been more variable, however. Recently, lung cancer and Hodgkin’s lymphoma appear to be declining in incidence, while the incidence of liver and anal cancer seems to be increasing. In addition, the population with HIV is ageing, and the incidence of certain cancers increases greatly with age.
As of 2010, two-thirds of cancers in people living with HIV were estimated to be non-AIDS-related. And it is important to note that people living with HIV still get prostate, colorectal and breast cancer, as well, though not in excess of what one would typically expect in the general population.
While most of these data come from industrialised countries – because of the availability of good cancer registries – there is some evidence that these trends are similar in developing regions of the world. During the session, Matthias Egger from the Universities of Bern and Cape Town presented data from five cohorts of South African children with HIV linked with cancer registries, identifying high numbers of KS and NHL and lower rates of non-AIDS-related cancers. Encouragingly, the risk of these cancers was about 70% lower among children on antiretroviral therapy.