Kaposi's sarcoma: malignant tumor or proliferative disorder?

In order to provide information on the response to treatments and clinico-pathological pattern, the clinical course of 41 patients with classic Kaposi's sarcoma (KS) was reconsidered. Twenty-six cases presented a single nodular lesion, and 15 multiple, pluricentric lesions. Surgery was the first treatment for patients with single lesions, 14 of 26 (54%) patients had recurrences: the disease-free interval ranged from a few months to 11 years. Five cases had disseminated disease, three of these were preceded by local recurrence. Cases with multiple lesions were treated by a combination of surgery, chemo- and radiation therapy (RT). In three cases spontaneous regression of disease was observed and two of these are presently disease-free. After chemotherapy and RT, many patients had complete remission of disseminated disease for up to 40 months. The drugs of first choice were vinblastine and bleomycin. Over all, only one patient died of KS, 10 years after diagnosis, nevertheless the cure rate was very poor and the final overall disease-free rate was around 30%. Proper treatment for nodular or disseminated lesions provides a fair disease-free period. Final considerations: mortality of disease is exceptional despite the 80% risk of recurrence or dissemination. Data from our series do not provide proof that adequate control of the primary single lesion could screen against recurrence: the interval between treatment of the first lesion and recurrence is sometimes exceptionally long, up to more than 10 years, and for that it is not easy to state when disease is really cured. These considerations and other analogies between KS and lymphoproliferative disorders in immunodepressed people strongly suggests the possibility of a non-malignant or even non-tumoral pattern to this disease, with implications for therapeutic strategies