Objectives: To determine whether the incidence of cancers other than the AIDS-defining cancers is increased in people with AIDS, and to determine if cancer incidence increases with time, a surrogate marker of declining immune function.
Design: Register-based retrospective cohort study in New South Wales, Australia. Age-, sex-, and period-adjusted standardized incidence ratios (SIR) were calculated for individual cancers occurring in 1980-1993 in people with AIDS registered before 1996.
Results: During the study period, 3616 people were registered with AIDS; 716 cases of AIDS-defining cancer and 62 cases of non-AIDS-defining cancer were identified. People with AIDS had a significantly increased incidence of Hodgkin's disease [SIR 18.3; 95% confidence interval (CI) 8.39-34.8], multiple myeloma (SIR 12.1; 95% CI 2.50-35.4), leukaemia (SIR 5.76; 95% CI 1.57-14.7), lip cancer (SIR 5.94; 95% CI 1.92-13.8) and lung cancer (SIR 3.80; 95% CI 1.39-8.29). The incidence of Hodgkin's disease increased significantly around the time of AIDS diagnosis (P = 0.008 for trend with time), suggesting an association with immunodeficiency.
Conclusions: This study provides strong support for the hypothesis that Hodgkin's disease is an AIDS-associated condition. There was an increased incidence of several other forms of cancer, some of which are known to occur at increased rates in transplant recipients who have received immunosuppressive therapy. Improved survival in people with HIV infection may lead to increases in the number that develop these forms of cancer.