Overview of the Management of AIDS-Related Kaposi's Sarcoma

Abstract

To review the epidemiology, pathogenesis, clinical presentation, diagnosis, and staging of Kaposi's sarcoma (KS), as well as the current role of local and systemic therapies in the management of AIDS-related KS (AIDS-KS). MEDLINE and CANCERLIT searches of the English-language medical literature were conducted. Emphasis was placed on studies published since the onset of the AIDS epidemic in the early 1980s. A manual review of selected bibliographies was also completed. AIDS-KS is a disease with a heterogeneous presentation that affects approximately 20% of patients with AIDS. Although the proportion of AIDS patients developing this disease during the course of their illness is declining, the actual number of AIDS-KS cases is increasing. The etiology of AIDS-KS is not clear, but a sexually transmitted cofactor has been implicated. Recent reports demonstrate that a herpes-like virus may be responsible for the development of KS in patients with and without AIDS. Furthermore, the cellular origin of KS has not been identified and questions remain about whether KS represents a true malignancy. The system used in staging patients with AIDS-KS has changed dramatically since initial therapeutic trials were conducted; this may account for observed differences in outcome among trials. The immunologic status of patients is now included as part of the staging system, since it has prognostic significance. Since specific therapy for AIDS-KS is not curative and does not prolong survival, it should be directed at improving patient cosmesis and palliation of disease-related symptoms. Local therapy, such as radiation, cryotherapy, and intralesional chemotherapy, is recommended for the management of limited disease. Systemic interferon alfa or chemotherapy is indicated for disseminated disease. Interferon alfa is useful in patients with predominantly mucocutaneous disease and is most effective in patients with good prognostic factors, such as absence of B symptoms, no history of opportunistic infections, and a CD4 count of more than 200 cells/mm3. Interferon alfa alone or in combination with zidovudine produces responses in approximately 30% of AIDS-KS patients with good prognostic factors. Single-agent or combination chemotherapy is indicated for rapidly progressive or advanced AIDS-KS. Commonly used agents include doxorubicin, daunorubicin, bleomycin, vincristine, and vinblastine. Responses can be expected in at least 50% of patients treated with single-agent or combination chemotherapy. However, many patients are unable to tolerate the toxicity associated with systemic AIDS-KS therapy. Future research will focus on therapies that target the underlying pathogenesis of this disease. The optimal therapy for patients with AIDS-KS has not been determined. Treatment is appropriately directed at palliation of disease-related symptoms as no therapy has been unequivocally proven to impact survival. Local therapies should be used in the management of localized disease, while systemic therapy is appropriate for disseminated disease. Interferon alfa is useful in patients with primarily mucocutaneous disease or asymptomatic visceral involvement. Chemotherapy is indicated in patients who have rapidly progressive or advanced disease. Therapy must be individualized according to the patient's disease course and other patient-specific factors.