e21500 Background: Classic Kaposi Sarcoma (CKS) is a rare and mild form of the disease that primarily affects men, older than 50 years in the endemic areas. Iatrogenic KS (IKS) is associated with the use of steroids, immunosuppressive agents in patients with autoimmune diseases, inflammatory disorders, or organ transplantation. We have conducted a retrospective analysis from January 2008 to December 2012 for CKS and IKS to evaluated outcomes and potential prognostic factors in this rare disease. Methods: Patients with histologically proven KS lesions of the skin and negative HIV-1/2 were enrolled. In some cases diagnosis was completed by immunohistochemical tests for HHV-8 staining. Eligible patients received different systemic chemotherapy for disease at stage IIb and in all variants of stage III and IV, according Mediterranean KS staging. Results: 32 cases of non-AIDS KS were identified in this study. Mean age at diagnosis of the group was 70 year-old. Approximate male/female ratio was 2:1. 78.2% of cases was classic KS. All patients received systemic chemotherapy containing one of this agent: alkaloid of vinca, taxane, pegylated lyposomial doxorubicin. Ten patients (31.5%) experienced a partial response, a complete response was achieved in 4 patients (12.4%) and stability in 16 cases (50%). Two patients (6.2%) developed multiple local recurrences. PFS was 11.7 months while OS resulted 28.5 months. At multivariate analysis nodular lesions were related to lower PFS compared to macular lesions (HR: 2,5817, 95% CI 1,2911 to 5,1624; p: 0,0049), and HHV8 status (positive vs. negative) had a statistically significant correlation with a worse response to treatment (HR: 5,0289 95% CI 1,6540 to 15,2901; p: 0,0046). Conclusions: Classic and iatrogenic KS patients appears less aggressive, mostly limited to the skin and well-responsive on local or systemic therapeutic strategies. Our data show as positivity to HHV8 and nodular lesions correlate with a worse response to treatment.