The incidence of AIDS-defining cancers (ADCs) - Kaposi sarcoma, primary central nervous system lymphoma, non-Hodgkin lymphoma, and cervical cancer - although on the decline since shortly after the introduction of HAART, has continued to be greater even in treated HIV-infected persons than in the general population. Although the survival of newly infected people living with HIV/AIDS now rivals that of the general population, morbidity and mortality associated with non-AIDS-defining cancers (NADCs) such as lung, liver, anal, and melanoma are significant and also continue to rise. Increasing age (i.e. longevity) is the greatest risk factor for NADCs, but longevity alone is not sufficient to fully explain these trends in cancer epidemiology. In this review, we briefly review the epidemiology and etiology of cancers seen in HIV/AIDS, and in this context, discuss preclinical research and broad treatment considerations. Investigation of these considerations provides insight into why malignancies continue to be a major problem in the current era of HIV/AIDS care.