Introduction

Malignancies have a significant impact on the morbidity and mortality of people with human immunodeficiency virus (HIV) infection. 30–40% of HIV-infected patients develop malignancies during the course of their illness. Some of the malignancies are AIDS-defining conditions whereas others appear to be more common in HIV patients (Box 20.1). Although AIDS-defining malignancies may be caused mainly by progressive immunosuppression, the exact relationship between immunosuppression and non-AIDS-defining malignancies is yet to be established. The most common cancers in the general population such as breast, prostate and colon do not appear to increase in HIV infection.

Introduction of highly active antiretroviral therapy (HAART) has brought significant changes to the natural history of HIV-infection. The incidence of Kaposi’s sarcoma and NHL has generally declined whilst the incidence of Hodgkin’s lymphoma and non-AIDS-defining cancers has not changed. With the introduction of antiretroviral therapy, 28% of deaths in HIV infection are due to cancer compared with 10% before HAART.

Pathogenesis

Development of cancers in HIV-infected individuals may be similar to that occurring in patients with immunosuppression and immune-deficiency disorders. The possible mechanisms for increased incidence of various malignancies in HIV-infected people include:

AIDS-defining malignancies