Treatment of classic Kaposi's sarcoma with α-interferon

The therapeutic approach to classic Kaposi's sarcoma (KS) is based on clinical course, size, distribution and extent of skin lesions. Surgical excision or cryotherapy are usually first therapies, while highly severe skin manifestations require systemic chemotherapy or radiotherapy. The efficacy of the treatment with low dosages of alpha-interferon (α-IFN) in classic KS has recently been reported. This paper presents our experience in treating 44 patients affected by histologically diagnosed and HIV negative classic KS which was treated with systemic α-IFN at 3 different Departments of Dermatology in Italy. The results obtained in four groups of patients are compared according to two variables, i.e. the different annual dosage used and the regimen of administration. The treatment has yielded good to excellent results in the majority of the cases both with low and middle-high doses. The first clinical result was a change in erythema and consistency, followed by a gradual decrease in size until complete disappearance. On the basis of our experience the percentage of improved patients is uniform in the different groups, in contrast to the percentage of stable patients and of drop-outs. The mechanism of action of α-IFN in KS is correlated with its antiproliferative and immunomodulating effects, but it is possible that it is also based on anti-angiogenesis activity by suppressing endothelial cell growth factors, as fibroblast growth factor (FGF). The results of this study, in terms of both responses to the therapy and the relative lack of side-effects, suggest that α-IFN therapy at low doses over one year can be considered a viable alternative to traditional therapies used in KS.