Risk factors for classical Kaposi's sarcoma.

Background: Classical Kaposi's sarcoma (KS) is a malignancy of lymphatic endothelial skin cells. Although all forms of KS are associated with the KS-associated herpesvirus (KSHV), classical KS occurs in a small fraction of KSHV-infected people. We sought to identify risk factors for classical KS in KSHV-infected individuals. Methods: Lifestyle and medical history data from case patients with biopsyproven non-AIDS (non-acquired immunodeficiency syndrome) KS in Italy were compared by logistic regression analysis with data from population-based KSHV-seropositive control subjects of comparable age and sex. After KSHV immunofluorescence testing, randomly selected patients on the rosters of local…