Etiological implications on Kaposi's sarcoma.

In attempts to encompass multiple events responsible for the development of cancer in man, with a particular interest to the possible involvement of viruses, multidisciplinary studies have been conducted on KS during 1971-1979. There is accumulating evidence associating this malignancy with CMV. African KS patients have high antibody titers to CMV, but they are not significantly different from controls of the same regions (Ag-Ab complexes?). A specific serologic association of European and American KS with CMV was established. CMV-related antigens can be demonstrated in 22% of tumor biopsies and comparably in early passages of cell culture derived from them. Recently, CMV-DNA sequences have been detected in tumor biopsies. Furthermore, a CMV, strain K9V, has been isolated in tissue culture from a KS culture. Cells infected in vitro with K9V have shown some of the characteristics of cells transformed previously by other oncogenic CMV strains. In vivo K9V has induced a fatal disease in old world monkeys, mainly involving the lymphoid system. Moreover, a cluster type of occurrence of KS was detected in the West Nile District of Uganda, an area with as high incidence of KS as BL; and finally, there is a significantly higher incidence of a second primary tumor in KS patients, particularly of the lymphoreticular system. Whether CMV plays a role in the development of KS, a complex neoplasia which involves different cell types cannot be claimed by these results only. However, similarities between CMV and EBV, the latter being closely associated with BL and nasopharyngeal carcinoma are worthy of consideration.