Objective: To describe the incidence of non-AIDS-defining cancers in people with HIV infection before and after the occurrence of AIDS, and to examine the association of cancer risk with immune deficiency.
Design: Cohort study involving nation-wide linkage of HIV, AIDS and cancer registry data.
Methods: Association of cancer risk with immune deficiency was examined by analysing cancer risks in four periods between HIV diagnosis, AIDS and death.
Results: Linkage identified 196 cases of non-AIDS-defining cancer in 8351 people notified with HIV infection and 8118 registered with AIDS (total of 13 067 individuals). Overall, we found significantly increased rates of cancer of the lip, anus, Hodgkin's disease, myeloma and leukaemia. Of these cancers, in people with HIV infection who did not develop AIDS, or were more than 5 years prior to development of AIDS, only cancer of the anus occurred at increased rates. A significant trend of increasing relative risk of cancer with increasing time since HIV diagnosis was found for Hodgkin's disease and multiple myeloma.
Conclusions: People with HIV with mild immune deficiency prior to AIDS were at increased risk of anal cancer, but this may reflect other risk factors. Other cancers occurred only later in the course of HIV infection. This is reassuring evidence that people with HIV who are only mildly immune deficient may not be at increased risk of non-AIDS-defining cancers, but larger studies with longer periods of follow-up are needed to confirm this.