Impact of the HIV epidemic on the epidemiology of cervical cancer

Cervical cancer and HIV infection are important causes of premature death among women in developing countries despite the fact that both are preventable. Previous studies suggest that HIV infection may modify the natural history of HPV infection and cervical dysplasia, facilitating a rapid progression to invasive cervical cancer. However, the results of studies conducted in Africa, where the prevalence of HIV infection in the female population is the highest, have been inconsistent. The goal of this dissertation, composed of three studies, was to assess the impact of the HIV epidemic on the epidemiology of cervical cancer, with a focus on sub-Saharan Africa.;The first chapter reviews the epidemiology and the possible biological cofactors that could explain a relationship between HIV and cervical cancer. Chapter 2 reports a systematic review of punished findings on the relationship between HIV infection and cervical cancer. There is substantial heterogeneity in the magnitude of the association in subgroup analysis, ranging from 1.7 to 9.2 for studies conducted in developing countries and developed countries, respectively. In addition to the differences in study designs, this heterogeneity could be the result of differences in population-specific prevalences of HPV infection and of other risk factors for cervical cancer.;Chapter 3 reports on the results of a case-control study of the relationship between HIV infection and invasive cervical cancer conducted in Ivory Coast, including data on HPV infection. This study was intended to assess a possible direct effect of HIV infection and the effect mediated by oncogenic HPV infection on the risk of cervical cancer. The main finding is that HIV infection is a cofactor of cervical cancer in women with HPV infection (OR 3.4; 95% CI 1.1-10.8), with a higher odds ratio among women aged ≤40 years (OR 4.5; 95% CI 1.5-13.6). HIV-infected women with cervical cancer were, on average, 10 years younger than HIV-uninfected women with cervical cancer and had only moderate immunosuppression.;Chapter 4 reports on a simulation study projecting the impact of HIV infection on the incidence of cervical cancer in a population. This study shows a significant excess burden of cervical cancer within 10 years of HIV infection in a population, with an attributables risk of 60% to 100% for a prevalence of HIV infection in the population ranging from 15% to 30%. The model should be validated with-population specific data for accurate predictions. Finally, chapter 5 highlights the importance of promoting cervical cancer screening in developing countries and of integrating cervical cancer screening services in ongoing HIV control programs.