Acquired immunodeficiency syndrome-associated cancers in Sub-Saharan Africa

Abstract

Sub-Saharan Africa is considered home to more than 60% of all human immunodeficiency virus (HIV) infected cases, with an estimated adult prevalence of 8.0%. It is stated that this region has contributed more than 90% of childhood deaths related to HIV infection and about 93% of childhood acquired immunodeficiency syndrome (AIDS)-related deaths. Although no country in Africa is spared of the infection, the bulk is seen in East and South Africa, with the highest recorded rates of 20% to 50% in Zimbabwe. On the other hand, West Africa is less affected, while countries in Central Africa have relatively stable infection rates. Although infections, especially tuberculosis, have emerged as the most important HIV/AIDS-associated killers in recent times, AIDS-associated malignancies are increasingly identified in the late stages. As a result of incomplete data from African countries, it is unclear whether the epidemiology and risks of these cancers are the same as observed in the developed countries. Since the advent of AIDS, epidemic Kaposi's sarcoma (KS) has become more common in both sexes in Africa, with a dramatic lowering of the male to female ratio from 19:1 to 1.7:1, especially in East Africa. Although there has been a rising trend of AIDS-associated non-Hodgkin's lymphoma (NHL) worldwide, there is an apparently lower risk in Africa compared with that in the developing world. At present, there is no strong evidence linking increased incidence of invasive cervical cancer to the HIV epidemic; however, some studies have demonstrated an association between HIV and the increased prevalence of human papilloma virus (HPV) and cervical intraepithelial neoplasia (CIN). On the other hand, HIV infection is now established as a risk factor for the development of squamous cell neoplasia of the conjunctiva based on studies from Rwanda, Malawi, and Uganda. Despite the problems and limitations of information from sub-Saharan Africa, interesting trends of HIV/AIDS-related cancers have emerged from comparison of available data.