Relation between demographic status and clinical characteristics of Kaposi sarcoma: a single centre study.

Kaposi sarcoma (KS) is a vascular tumour with four main clinical types-classic, endemic, iatrogenic, and epidemic-all linked to infection by human herpesvirus 8 (HHV-8). This retrospective cohort study assessed the relationship between demographic factors and clinical characteristics in 73 patients with biopsy-proven KS treated at a single dermatology centre between 2009 and 2023. Demographic and clinical data, including age, gender, birthplace, blood type, smoking, alcohol use, HIV status, tumour site, and disease stage, were collected and statistically analysed. Most patients were male (77%), with a mean age of 61 years, and the classic KS subtype predominated (86%). The majority (75%) had tumours localised to the extremities. HIV-positive status was diagnosed in 14% of cases and was strongly associated with non-extremity tumour location and increased visceral involvement. Notably, blood type showed a significant association with tumour localisation: 0Rh- and ARh- blood groups were less common in KS patients with extremity tumours. This is the first study to demonstrate a significant relationship between blood group and KS tumour site, introducing a novel epidemiological association. Smoking and alcohol consumption were each significantly linked to higher HIV positivity rates. Patients from the Mediterranean region had a higher frequency of HIV-positive KS, although birthplace did not correlate with disease stage. No associations were observed between gender and disease type. The study is limited by its retrospective design and missing data for certain variables, but it identifies potentially novel patterns-including a possible link between blood group and tumour location-and confirms known associations, such as HIV status with advanced disease. These findings underscore the complexity of KS presentation and suggest that demographic, clinical, and lifestyle factors may shape disease patterns. Prospective, multicentre studies are needed to validate these findings and guide personalised approaches to KS management.