[Classical Kaposi sarcoma and volcanic soil in southern Italy: a case-control study].

We tested the hypothesis of a relationship between Kaposi's sarcoma (KS) and volcanic soil by means of a case-control study based on 70 cases of classic KS and 280 hospital controls from the Campania region, an area of active volcanism in the South of Italy. Birth and residence in volcanic areas were associated with approximately two-fold elevated KS risks. If not due to chance, increased risk in the presence of volcanic soil can have different interpretations, including local immune impairment and correlation with unknown environmental or genetic KS predisposing factors.