Predictors of Developing Hepatocellular Carcinoma in Treated HCV-Carriers in Morocco according to University Hospital Experience

Hepatocellular carcinoma screening is indicated even after sustained virological response: -Moroccan University Hospital Experience-

Introduction: Hepatitis C is the first aetiologic agent for HCC in Morocco. Antiviral treatment reduces the risk of developing HCC in patients with chronic hepatitis C but few cases of HCC have been still reported. We aimed to define population with high risk of HCC occurrence, confirm the protective role of SVR and to identify predictive factors of developing HCC after SVR. We'll try to present suggestions about screening strategies (indications and interval) after antiviral therapy according to level of HCC occurrence risk. Patients and Methods: We included all patients with chronic hepatitis C treated in our department from January 2002 to April 2010. We compare HCV-treated patients with no developed HCC to HCC population using khi-2 and Fisher Exact analysis. Results: 369 patients treated for hepatitis C were considered, and 20 HCC were reported. The risk of HCC occurrence was not significant according to gender and genotypes. Advanced age and severe fibrosis were significant risk factors. HCC was reported in 2.3% of sustained virological responders versus 12.5% of non responders. SVR is a significant protective factor. Conclusion: In our series, 5% of previously treated HCV carriers developed HCC and 2.3% of sustained virological responders developed. Achieving SVR after antiviral therapy is a protective factor. Advanced age (> 50 y. o), severe fibrosis (F>2) and lack of SVR at HCV diagnosis are predictive factors of HCC development in treated patients. Regular bi-annual ultrasonography screening should be indicated necessarily in patients with advanced fibrosis stage (F3- F4) even after SVR, particularly when co-morbid conditions are associated (advanced age, NASH, diabetes mellitus,...). Screening interval in sustained virological responders with reduced fibrosis stage may be limited to annual surveillance. Establishing guidelines about consensual strategy to survey sustained virological responders is now necessary especially with high rates of SVR and the extension of treatment indications in era of DAA drugs. Keywords: Hepatocellular Carcinoma (HCC), Screening, Sustained Virological Response (SVR)

TP53 R72P polymorphism modulates DNA methylation in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is characterized by widespread epidemiological and molecular heterogeneity. Previous work showed that in the western part of North Africa, a region of low incidence of HCC, mutations are scarce for this tumor type. As epigenetic changes are considered possible surrogates to mutations in human cancers, we decided, thus, to characterize DNA methylation in HCC from North-African patients.

METHODS

A set of 11 loci was investigated in a series of 45 tumor specimens using methylation-specific and combined-bisulfite restriction assay PCR. Results obtained on clinical samples were subsequently validated in liver cancer cell lines.

RESULTS

DNA methylation at tumor suppressor loci is significantly higher in samples displaying chromosome instability. More importantly, DNA methylation was significantly higher in Arg/Arg when compared to Pro/Pro genotype carriers at codon 72 rs1042522 of TP53 (65% vs 20% methylated loci, p = 0.0006), a polymorphism already known to affect somatic mutation rate in human carcinomas. In vitro experiments in cell lines indicated that enzymes controlling DNA methylation were differentially regulated by codon 72 Arg or Pro isoforms of p53. Furthermore, the Arg72-carrying version of p53 was shown to re-methylate DNA more rapidly than the pro-harboring isoform. Finally, Pro-carrying cell lines were shown to be significantly more resistant to decitabine treatment (two-fold, p = 0.005).

CONCLUSIONS

Our data suggest that Arg72Pro polymorphism in a WT p53 context may act as a primary driver of epigenetic changes in HCC. It suggests, in addition, that rs1042522 genotype may predict sensitivity to epigenetic-targeted therapy. This model of liver tumorigenesis that associates low penetrance genetic predisposition to epigenetic changes emerges from a region of low HCC incidence and it may, therefore, apply essentially to population living in similar areas. Surveys on populations submitted to highly mutagenic conditions as perinatally-acquired chronic hepatitis B or aflatoxin B1 exposure remained to be conducted to validate our observations as a general model.