Classic Kaposi sarcoma in northern Sardinia: A prospective epidemiologic overview (1977-2003) correlated with malaria prevalence (1934)

Abstract

Studies have demonstrated considerable variations in classic Kaposi sarcoma (CKS) incidence within Europe, with some of the highest incidences found in the Mediterranean area. As a Mediterranean area, northern Sardinia has a high CKS frequency. In order to determine CKS incidence in people born in and residing in northern Sardinia, a clinical prospective epidemiologic study was carried out between 1977 and 2003 by the Department of Dermatology, University of Sassari. We also evaluated a correlation between malaria prevalence in 1934, estimated on the eight historical sub-areas of the Sassari province, and the standardized morbidity ratio from 1977 to 2003. A total of 332 patients with CKS were identified. Incidence among the northern Sardinian population > or =40 years of age was 4.06/100,000 persons/year and it was almost stable through the years. The male to female ratio showed a significant decline from 3.6 to 2.5 (P = .03). Females had a statistically decreased risk of developing CKS compared to males (adjusted incidence rate ratio = 0.27; 95% CI: 0.21-0.34), and the risk of developing CKS increased exponentially with age. The prevalence of malaria in each sub-area ranged from 9% to 91%. The standardized morbidity ratio for CKS in the years between 1977 and 2003 ranged from 0.27 to 1.76; the regression coefficient was -0.85 (95% CI: -2.94-1.24), yielding a nonsignificant relationship between the two diseases. These results were obtained from patients with CKS in northern Sardinia and may not be applicable to other populations. The northern Sardinian population consistently has a very high incidence of CKS, while in our data, the correlation between malaria and CKS remains open to question.