The United States Center for Disease Control recognises three malignancies as AIDS-defining conditions.

These are Kaposi's sarcoma, intermediate or high grade B-cell non-Hodgkin's lymphoma (NHL) and cervical carcinoma. Primary central nervous system lymphoma is a rare B-cell NHL that is often considered separately from the other NHLs.

The investigation and treatment of suspected malignancy is complicated by unusual presentations and sites of disease, concomitant infections and immunosuppression. Malignancies may occur at different points in the disease process for different individuals and management must be tailored to the patient's overall maximum benefit.

There are many new developments in the understanding of the pathogenesis of AIDS-related malignancies and in the future these will inform new therapies. In the last few years alone highly active antiretroviral therapy (HAART) has had a great impact on the incidence and natural history of some of these malignancies. As opportunistic infections are more easily treated and patients live longer the malignancies are likely to become relatively more common. The incidence of AIDS-related malignancies varies within the different population groups with HIV and as affected groups evolve there will doubtless be a change in the incidence of malignancies seen in the UK. With these rapid changes optimal treatment strategies are controversial and patients should be entered into clinical trials.

Table 5.1 Risk of malignancies in HIV-positive patients

Relative risk compared to HIV-negative

Box 5.1 Clinical groups of patients with Kaposi's sarcoma (KS)

• “Classic” KS: elderly, predominantly male, Jewish or Eastern European

• “Endemic” or African KS (various types)

• Immunosuppression-related KS (patients with transplants)

• “Epidemic” or AIDS-related KS