AIDS-Related Kaposi's Sarcoma: State of the Art and Therapeutic Strategies

In the HAART era Kaposi's sarcoma (KS) remains the second most frequent tumor in HIV-infected patients worldwide, and it has become the most common cancer in Sub-Saharan Africa. In western countries the risk for KS in men having sex with men (MSM) is 5 to 10 times higher compared to other groups of individuals practicing other HIV-risk behaviors. Patients with KS in Sub-Saharan Africa have very high tumor burdens and rapid disease progression with a diminished life expectancy of less than 6 months. KS lesions are comprised of both distinctive spindle cells of endothelial origin and a variable inflammatory infiltrate, which suggests that KS may result from reactive hyperproliferation induced by chronic inflammation, and therefore it is not a true neoplasm. KS has a variable clinical course ranging from very indolent forms, requiring no or minimal therapy, to a rapidly progressive disease. Treatment decisions must take into consideration the extent and the rate of tumor growth, patient's symptoms, immune system conditions and concurrent HIV-related complications. Several different therapeutic options are available but the optimal therapy is still unclear. Highly Active Antiretroviral Therapy (HAART) including protease inhibitors (PI) may represent the first treatment step for slowly progressive disease; chemotherapy (CT) plus HAART is indicated for visceral and/or rapidly progressive disease, whereas maintenance (M)-HAART after systemic chemotherapy may be an effective anti-KS measure after debulking CT. The angiogenic nature of KS makes it particularly suitable for therapies based on targeted agents such as metalloproteinase inhibitors, angiogenesis inhibitors and tyrosine kinase inhibitors. The aim of this article is to provide an up-to-date review of the current status and perspectives of AIDS-related KS in the HAART era.