Thèse de doctorat en Épidémiologie
Soutenue le 24-06-2013
à Lyon 1 , dans le cadre de École Doctorale de Biologie Moléculaire Intégrative et Cellulaire (Lyon) , en partenariat avec Centre international de recherche sur le cancer (laboratoire) .
Le président du jury était Annie Sasco.
Description spatio-temporelle de l'incidence des cancers liés au sida en Afrique du Nord et subsaharienne et de la mortalité des patients HIV-séropositifs en Algérie et prévalence de l'hépatite C chez les patients atteints de lymphome non-hodgkinien en Algérie
Background: In Africa, the prevalence of HIV/AIDS and hepatitis C virus (HCV) has been the highest in the world. Furthermore, cancer incidence is increasing. Objective: This thesis work presents a part of the impact of these infections on the cancer burden in northern and sub-Saharan Africa. AIDS-related cancers, namely Kaposi sarcoma (KS), non-Hodgkin lymphoma (NHL), and cervical cancer, were described to assess the impact of HIV/AIDS on cancer epidemiology in Algerian, Tunisian, Egyptian, Ugandan, and Zimbabwean populations. Furthermore, for the impact of HCV infection, the epidemiology of NHL as an extra-hepatic HCV-related cancer was also studied. Results: Ugandan HIV/AIDS prevalence has declined since the early 1990s, and in Zimbabwe, after an increase until the end of the 1990s, rates have gone down. In Algeria, the retrospective study performed during this thesis work showed that risk of death and standardized mortality ratio, comparing the mortality of HIV-positive patients with that of the general population, have decreased after the introduction of highly active antiretroviral therapy (HAART) in 1998 in Algeria. However, the late stage of the disease among HIV/AIDS patients at diagnosis warns of the high risk of HIV/AIDS transmission. These observations suggest that Algeria needs to couple HAART use with a more effective prevention programme to fight the increase in the number of HIV/AIDS cases. KS incidence was higher in the sub-Saharan African populations studied than in the northern African populations; however, among women it was similar in Uganda and Zimbabwe. With the emergence of the HIV/AIDS epidemic, KS incidence increased dramatically in both sub-Saharan African populations studied, and it has followed the HIV/AIDS time trend in Zimbabwe. However, in Uganda although HIV/AIDS prevalence has decreased, KS incidence has remained stable among women and elderly men (>50 years old). The decrease in KS incidence was observed only in young Ugandan men (<50 years old). In Uganda and Zimbabwe, we observed an equal or higher KS incidence in men than in women, whereas HIV/AIDS prevalence was higher among women. In northern Africa, KS incidence has remained low and was similar between the populations studied. Regarding NHL, incidence has been highest among both genders in Egypt, while HIV/AIDS has been rare. In Egypt, NHL has seemed to be attributable to HCV infection. In Algeria, another country with low HIV/AIDS prevalence where NHL incidence has increased, a background investigation of NHL patients showed an HCV prevalence of 5.6%. HCV infection may partly explain NHL emergence, especially among a high-risk group of patients for HCV nosocomial contamination. In eastern Algeria, patients found with NHL and HCV infection were elderly women with primarily nosocomial risk factors for HCV contamination. Cervical cancer followed the north–south HIV/AIDS distribution; however, its incidence varied among northern African populations where HIV/AIDS prevalence was similar. Conclusion: KS, NHL, and cervical cancer epidemiology are related to that of HIV/AIDS; however, other infections – human herpesvirus 8 for KS, HCV for NHL, and human papillomavirus for cervical cancer – have influenced the geographical patterns and the time trends of these cancers