Clinical aspects and management of AIDS-related Kaposi's sarcoma

AIDS-related Kaposi's sarcoma (KS) is a tumour of vascular endothelium, which is seen predominantly in men who have sex with men. The majority of affected individuals have advanced immunosuppression at the time of the initial KS diagnosis. The disease may present with cutaneous lesions, or with involvement of visceral organs, of which the gastrointestinal tract is most common. KS may also present with lymphoadenopathy or with isolated lymphoedema, even in the absence of cutaneous lesions. Affected individuals are uniformly co-infected with HIV and with Human Herpesvirus type 8 (HHV8). HHV8 is present within KS tissues, and is aetiological in the pathogenesis of disease, along with aberrant cytokine expression, production of multiple angiogenic peptides, and immune dysregulation. While not presently curable, multiple treatment options exist and must be evaluated in terms of the specific needs of the individual patient. Various local therapies are aimed at eradicating small lesions, while acknowledging that the KS in general, or its likelihood of recurring will be unaffected. Systemic chemotherapy is used to treat extensive visceral involvement. Knowledge of the pathogenesis of disease has led to the development of novel treatment strategies, aimed at HHV8 as the target of therapy, or at the inflammatory cytokine or angiogenic milieu necessary for KS growth. Use of highly active anti-retroviral therapy, aimed at controlling the underlying HIV infection, has been associated with a dramatic decrease in the incidence of KS, and may also be useful in the treatment of existing KS disease.