Classic Kaposi's sarcoma in southern Sardinia, Italy

Kaposi's sarcoma (KS) is a multifocal vascular neoplasm (Ziegler et al, 1988), but the nature of the proliferating cells, and whether the lesions represent an exuberant hyperplasia or a true malignancy are still disputed (Buonaguro et al, 1995). The association with HHV8 infection in all forms of the disease (Babal and Pect, 2003) is consistent with a common pathologic process, but certain clinical-epidemiological aspects differentiate the course, the prognosis, and treatment of each form. Classical KS corresponds to the original description (Kaposi, 1872), and predominantly affects elderly males, with a higher incidence in southern and eastern European countries, with a predominance among Jews and people of Mediterranean descent (Ziegler et al, 1988, Mackie, 1992; Franceschi and Geddes, 1995). Prior to the AIDS epidemic, KS incidence rates were two- to three-fold higher in Italy than in the USA and Sweden, and as much as tenfold higher than in England and Australia (Geddes et al, 1994). In north-eastern Sardinia (Italy), classic KS incidence rate is among the highest in the world at 1.59 per 100 000 (Cottoni et al, 1996). Sardinia has a Mediterranean homogeneous island population of ancient origin; genetic studies have already demonstrated a positive association of KS with the HLA-DR5 haplotype (Contu et al, 1984). We have investigated whether KS incidence rate is elevated also in the southern part of Sardinia, which includes the capital city Cagliari. We also compared incidence rates in urban and rural areas, as a surrogate for environmental factors in KS aetiology.