Aids-related malignancies

Several different types of cancer are observed at an increased frequency in acquired immune deficiency syndrome (AIDS) patients and in other immunosuppressed individuals. Most of these are virus-associated cancers. Kaposi's sarcoma (KS) is the most common neoplasm that occurs in patients with AIDS (AIDS-KS). KS is believed to be caused by Kaposi's-sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8), but the tumour microenvironment is an important aspect of KS progression. AIDS-lymphoma is another significant cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected individuals. Over 50% of AIDS lymphomas are associated with Epstein–Barr virus (EBV) and/or KSHV infection. EBV activates B-cell precursors, leading to a transformed phenotype. Human papillomavirus (HPV)-related cancers are another type of AIDS-related malignancy. There are likely to be two mechanisms by which papillomaviruses induce neoplasia — by altering the tumour microenvironment, and by directly disrupting cell differentiation, to induce cell proliferation. Antiviral strategies might be used to prevent cancer in AIDS patients. For example, highly active antiretroviral therapy has been shown to prevent or stop the progression of KS in AIDS patients.