The Challenge of AIDS-Related Malignancies in Sub-Saharan Africa

Abstract

BackgroundWith the lengthening of life expectancy among HIV-positive subjects related to the use of highly active antiretroviral treatments, an increased risk of cancer has been described in industrialized countries. The question is to determine what occurs now and will happen in the future in the low income countries and particularly in sub-Saharan Africa where more than two-thirds of all HIV-positive people live in the world. The objective of our paper is to review the link between HIV and cancer in sub-Saharan Africa, putting it in perspective with what is already known in Western countries.Methods and FindingsStudies for this review were identified from several bibliographical databases including Pubmed, Scopus, Cochrane, Pascal, Web of Science and using keywords “HIV, neoplasia, epidemiology and Africa” and related MesH terms. A clear association was found between HIV infection and AIDS-classifying cancers. In case-referent studies, odds ratios (OR) were ranging from 21.9 (95% Confidence Interval (CI) 12.5–38.6) to 47.1 (31.9–69.8) for Kaposi sarcoma and from 5.0 (2.7–9.5) to 12.6 (2.2–54.4) for non Hodgkin lymphoma. The association was less strong for invasive cervical cancer with ORs ranging from 1.1 (0.7–1.2) to 1.6 (1.1–2.3), whereas ORs for squamous intraepithelial lesions were higher, from 4.4 (2.3–8.4) to 17.0 (2.2–134.1). For non AIDS-classifying cancers, squamous cell conjunctival carcinoma of the eye was associated with HIV in many case-referent studies with ORs from 2.6 (1.4–4.9) to 13.0 (4.5–39.4). A record-linkage study conducted in Uganda showed an association between Hodgkin lymphoma and HIV infection with a standardized incidence ratio of 5.7 (1.2–17) although OR in case-referent studies ranged from 1.4 (0.7–2.8) to 1.6 (1.0–2.7). Other cancer sites found positively associated with HIV include lung, liver, anus, penis, vulva, kidney, thyroid and uterus and a decreased risk of female breast cancer. These results so far based on a relatively small number of studies warrant further epidemiological investigations, taking into account other known risk factors for these tumors.ConclusionStudies conducted in sub-Saharan Africa show that HIV infection is not only strongly associated with AIDS-classifying cancers but also provided some evidence of association for other neoplasia. African countries need now to implement well designed population-based studies in order to better describe the spectrum of AIDS-associated malignancies and the most effective strategies for their prevention, screening and treatment.

Cancer in Africa 2012

“…7). KS is an HIV-associated cancer caused by human herpes virus-8 (34,35). Although KS continues to be a leading cause of cancer in most parts of Eastern Africa, rates are declining because of reduction in prevalence of HIV and wider availability of highly active antiretroviral therapy (12,13,36).…”

Propranolol Decreases Proliferation of Endothelial Cells Transformed by Kaposi's Sarcoma-Associated Herpesvirus and Induces Lytic Viral Gene Expression

“…Targeting these altered processes in vitro has identified novel treatment targets (2)(3)(4)(5). However, economic constraints prevent clinical translation of many of these observations in areas of high KS burden, so systemic cytotoxic agents, where available, remain the mainstay of KS treatment (6,7).…”

Virus-Induced Cancers in Africa: Epidemiology and Carcinogenesis Mechanisms

“…The viral genome is a positive single-stranded RNA of 9000 bp present in two copies, flanked by two Long Terminal Repeats (LTR) between which lie the usual three genes of the family, Gag, Pol and Env, and pX gene that encodes for two regulatory proteins (Tax and Rex) involved in the oncogenic process [39]. Contrary to the mechanism of oncogenic retroviruses involving cis-activators or transducers, HTLV-1 has no viral oncogene similar to cellular proto-oncogene (v-onc) and is therefore not responsible for the malignant process.…”