Cancers primitifs du foie au Cameroun : Epidémiologie, étiologie virale et altérations génétique

Abstract

Primary liver cancer (PLC) is the most common cause of cancer-related death in sub-Saharan Africa and particularly in Cameroon. To date, little is known on the incidence and etiology of primary liver cancer in this area. The current study was undertaken to identify the different types of primary liver cancer diagnosed in Cameroon and to investigate the virological risk factors and the genetic alterations associated with the development of this malignancy in Cameroon using a retrospective and a case control study. A retrospective study was undertaken in the Anatomy and pathology of the Centre Pasteur of Cameroon to assess the incidence of the different types of PLC in Cameroon. Subsequently, a case control study was conducted in the Gastroenterology Unit of Central Hospital of Yaounde in collaboration with the Centre Pasteur of Cameroon. This part of the work was conducted in order to identify the viral etiology and genetics alterations associated with the development of PLC.Viral agents associated with the development of PLC were searched by identification of serological markersand several molecular factors including viral load, genotypes and genetics mutations. In the current study, genetics alteractions circulating in the blood of HCC patients and control individuals were assessed by identification of several mutations and polimorphisms. Overall, only HCC (98.8%) and hepatoblastoma (1.2%) were diagnosed over a period selected. The risk factors analysis showed that hepatitis B, C, D and E viruses were strongly associated with HCC development in Cameroon with odds ratios of 15.98 (95% CI 6.19-41.25), 7.33 (95% CI 2.09-25.77), 29.3 (95% CI, 4.1-1231) and 5.8 (2.3-18) respectively. Furthermore, the risk of developing HCC increased even more significantly in cases of hepatitis B and C co-infections, an increase viral load more than 10 000UI/ml, infection with hepatitis B quasisubgenotype A3 or hepatitis C genotype 4f and several genetics mutations. Regarding genetic alterations, HCC patients displayed lower levels of circulating mitochondrial DNA whereas the TP53 R249S mutation was found to be significantly (P<0.05) more frequent as compared to controls. The TP53 R72P polymorphisms distribution and mitochondrials haplogroups were statistically similar in HCC cases and controls. As a conclusion, HCC was the only PLC diagnosed among adults in Cameroon. Infection with hepatitis B, C, D and E represent the main viral cause of HCC in Cameroonian patients. Mitochondrial DNA and R249S mutation of the p53-encoding gene were the only genetic alterations found statistically different in HCC cases and compared controls. They could be used as biomarkers for early diagnosis and prognosis of HCC.