What's new in malignant tumors in acquired immunodeficiency disorders?

An increased incidence of malignant tumors has long been recognized in patients with primary immune defects such as the X-linked lympho-proliferative syndrome or the Wiskott Aldrich syndrome and has recently become a major concern also in cases with acquired immunodeficiency. The latter may be induced by cytostatic therapy for cancer, extended immunosuppression following organ transplantation or HIV infection. The spectrum of secondary cancers is, however, different within these three groups of secondary immune defects with acute myeloid leukemia being the most common malignant disease after cytostatic therapy, with skin or lip cancer followed by non-Hodgkin's lymphoma as the prevalent malignancies after organ transplantations and Kaposi sarcoma and non-Hodgkin's lymphoma as the predominant cancers associated with HIV infection. The pathogenesis of Kaposi sarcoma and non-Hodgkin's lymphoma is possibly related to viral infections by cytomegalovirus and Epstein-Barr virus inducing an increased proliferation and possibly the coactivation of transforming genes of oncogenic potential. In AIDS patients Kaposi sarcoma is diagnosed in up to 40% of homosexual men while the other risk groups are less frequently involved. 4-10% of HIV infected patients experience non Hodgkin's lymphoma predominantly of B-cell type and intermediate or high grade malignancy with frequent extranodal manifestations. Other types of tumors occur at a substantially lower frequency and are not clearly related to the HIV infection. The overall survival of patients suffering from malignant tumors in the state of immunodeficiency is poor and the possibilities for therapeutic intervention are limited by the risk of accelerating the pre-existing suppression of defense mechanisms.