A description of Kaposi sarcoma risk factors and outcomes in HIV-positive and HIV-negative patients at a tertiary care medical center from 2005 to 2020.

Kaposi sarcoma (KS) is a low-grade vascular malignancy caused by human herpesvirus-8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV). There are four established subtypes of KS, which are described by unique risk factors, presentation, and disease course. A "non-epidemic" variant to describe HIV-negative men who have sex with men (MSM) is emerging as a fifth subtype. We retrospectively examined patients with KS at an academic medical center in central Ohio, USA. To our knowledge, this is the first US-based report to describe KS risk factors and outcomes in the context of HIV status. Data were extracted from patient charts including demographic information, history at time of KS diagnosis, and information about KS disease course. HIV-positive and HIV-negative patients were grouped into established categories. HIV-negative patients who did not fit an existing subtype were described as "Unclassified-KS-Type." Demographic characteristics for AIDS-KS patients in our cohort match established trends in this subtype, such as male, MSM, and younger age at diagnosis compared to HIV-negative patients. Most Unclassified-KS-Type patients fit well into the emerging "non-epidemic KS" subtype. These patients are described as healthy, middle-aged, HIV-negative MSM with lower extremity lesions. This descriptive report provides an updated view of KS risk factors and outcomes to improve detection and treatment in dermatology.