Hepatitis C treatment and liver cancer recurrence: cause for concern?

Nonalcoholic fatty liver disease and hepatocellular carcinoma:Insights in epidemiology, pathogenesis, imaging, prevention and therapy

Hepatocellular carcinoma (HCC) is estimated to be the third leading cause of cancer-related mortality and is characterized by low survival rates. Nonalcoholic fatty liver disease (NAFLD) is emerging as a leading cause of HCC, whose rates are increasing, owing to the increasing prevalence of NAFLD. The pathogenesis of NAFLD-associated HCC is multifactorial: insulin resistance, obesity, diabetes and the low-grade hepatic inflammation, which characterizes NAFLD, seem to play key roles in the development and progression of HCC. The diagnosis of NAFLD-associated HCC is based on imaging in the presence of liver cirrhosis, preferably computerized tomography or magnetic resonance imaging, but liver biopsy for histological confirmation is usually required in the absence of liver cirrhosis. Some preventive measures have been recommended for NAFLD-associated HCC, including weight loss, cessation of even moderate alcohol drinking and smoking, as well as the use of metformin, statins and aspirin. However, these preventive measures are mainly based on observational studies, thus they need validation in trials of different design before introducing in clinical practice. The treatment of NAFLD should be tailored on an individual basis and should be ideally determined by a multidisciplinary team. In the last two decades, new medications, including tyrosine kinase inhibitors and immune checkpoints inhibitors, have improved the survival of patients with advanced HCC, but trials specifically designed for patients with NAFLD-associated HCC are scarce. The aim of this review was to overview evidence on the epidemiology and pathophysiology of NAFLD-associated HCC, then to comment on imaging tools for its appropriate screening and diagnosis, and finally to critically summarize the currently available options for its prevention and treatment.

NASH and Hepatocellular Carcinoma: Immunology and Immunotherapy

The last 10 years have revolutionized our basic understanding of nonalcoholic fatty liver disease and consequent liver cancer. It has become clear that several innate and adaptive immune cells play an important role in initiating, maintaining, or exacerbating nonalcoholic steatohepatitis (NASH)-a disease that has been recently defined as autoaggressive. Despite improved disease management aimed at reducing the progression of fibrosis, NASH is set to become a leading cause for hepatocellular carcinoma (HCC). Preliminary data from preclinical studies suggest that immunotherapy efficacy may be reduced in NASH-related HCC compared with viral HCC; however, conclusive evidence supporting clinical translation of these findings is lacking. Comprehensive clinical and immunologic phenotyping of mechanisms linking NASH progression with carcinogenesis and therapeutic resistance is key to prevent progression to cirrhosis, improve monitoring and stratification of NASH according to predicted cancer risk, and ultimately increase survival of patients with NASH-HCC. In this review, we summarize the state of the art in the field of NASH and NASH-HCC with focus on immunobiology. We discuss preclinical and clinical findings underpinning NASH as an immunologically distinct pro-tumorigenic disease entity, and explore areas of potential therapeutic vulnerabilities in NASH-associated HCC.

Emerging Evidence for Infectious Causes of Cancer in the United States

Worldwide, infectious agents currently contribute to an estimated 15% of new cancer cases. Most of these (92%, or 2 million new cancer cases) are attributable to 4 infectious agents: Helicobacter pylori, human papillomavirus, and hepatitis B and C viruses. A better understanding of how infectious agents relate to the US cancer burden may assist new diagnostic and treatment efforts. We review US-specific crude mortality rates from infection-associated cancers and describe temporal and spatial trends since 1999. We review the US-specific evidence for infection-cancer associations by reporting available estimates for attributable fractions for the infection-cancer associations. Death due to cancers with established infectious associations varies geographically, but estimates for the US attributable fraction are limited to a few observational studies. To describe the burden of infection-associated cancer in the United States, additional observational studies are necessary to estimate the prevalence of infection nationally and within subpopulations. As infectious associations emerge to explain cancer etiologies, new opportunities and challenges to reducing the burden arise. Improved estimates for the United States would help target interventions to higher-risk subpopulations.

The hepatitis C viral nonstructural protein 5A stabilizes growth-regulatory human transcripts

Numerous mammalian proto-oncogene and other growth-regulatory transcripts are upregulated in malignancy due to abnormal mRNA stabilization. In hepatoma cells expressing a hepatitis C virus (HCV) subgenomic replicon, we found that the viral nonstructural protein 5A (NS5A), a protein known to bind to viral RNA, also bound specifically to human cellular transcripts that encode regulators of cell growth and apoptosis, and this binding correlated with transcript stabilization. An important subset of human NS5A-target transcripts contained GU-rich elements, sequences known to destabilize mRNA. We found that NS5A bound to GU-rich elements in vitro and in cells. Mutation of the NS5A zinc finger abrogated its GU-rich element-binding and mRNA stabilizing activities. Overall, we identified a molecular mechanism whereby HCV manipulates host gene expression by stabilizing host transcripts in a manner that would promote growth and prevent death of virus-infected cells, allowing the virus to establish chronic infection and lead to the development of hepatocellular carcinoma.

Epidemiology and Elimination of HCV-Related Liver Disease

Hepatitis C virus (HCV) infection, defined by active carriage of HCV RNA, affects nearly 1.0% of the worldwide population. The main risk factors include unsafe injection drug use and iatrogenic infections. Chronic HCV infection can promote liver damage, cirrhosis and hepatocellular carcinoma (HCC) in affected individuals. The advent of new second-generation, direct-acting antiviral (DAA) agents allow a virological cure in more than 90% of treated patients, and therefore prevent HCV-related complications. Recently, concerns have been raised regarding the safety of DAA-regimens in cirrhotic patients with respect to the occurrence and the recurrence of HCC. Here, we review the current available data on HCV epidemiology, the beneficial effects of therapy, and discuss the recent controversy with respect to the potential link with liver cancer. We also highlight the challenges that have to be overcome to achieve the ambitious World Health Organization objective of HCV eradication by 2030.

Incidence of Hepatocellular Carcinoma in Patients With HCV-Associated Cirrhosis Treated With Direct-Acting Antiviral Agents

BACKGROUND & AIMS

Studies have produced conflicting results of the incidence of hepatocellular carcinoma (HCC) in patients with hepatitis C virus-associated cirrhosis treated with direct-acting antivirals (DAAs). Data from clinics are needed to accurately assess the occurrence rate of HCC in patients with cirrhosis in the real world.

METHODS

We collected data from a large prospective study of 2,249 consecutive patients (mean age = 65.4 years, 56.9% male) with hepatitis C virus-associated cirrhosis (90.5% with Child-Pugh class A and 9.5% with Child-Pugh class B) treated with DAAs from March 2015 through July 2016 at 22 academic and community liver centers in Sicily, Italy. HCC occurrence was evaluated by Kaplan-Meier curves. Cox regression analysis was used to identify variables associated with HCC development.

RESULTS

A sustained virologic response (SVR) was achieved by 2,140 patients (total = 95.2%; 95.9% with Child Pugh class A and 88.3% with Child Pugh class B; P < .001). Seventy-eight patients (3.5%) developed HCC during a mean follow-up of 14 months (range = 6-24 months). At 1 year after exposure to DAAs, HCC developed in 2.1% of patients with Child-Pugh class A with an SVR and 6.6% of patients with no SVR and in 7.8% of patients with Child-Pugh class B with an SVR and 12.4% of patients with no SVR (P < .001 by log-rank test). Albumin level below 3.5 g/dL (hazard ratio = 1.77, 95% confidence interval = 1.12-2.82, P = .015), platelet count below 120 × 10⁹/L (hazard ratio = 3.89, 95% confidence interval = 2.11-7.15, P < .001), and absence of an SVR (hazard ratio = 3.40, 95% confidence interval = 1.89-6.12, P < .001) were independently associated increased risk for HCC. The mean interval from exposure to DAAs to an HCC diagnosis was 9.8 months (range = 2-22 months) and did not differ significantly between patients with (n = 64, 9.2 months) and without (n = 14, 12.0 months) an SVR (P = .11). A larger proportion of patients with an SVR had a single HCC lesion (78% vs 50% without an SVR; P = .009) or an HCC lesion smaller than 3 cm (58% vs 28% without an SVR; P = .07).

CONCLUSIONS

In an analysis of data from a large prospective study of patients with hepatitis C virus-associated compensated or decompensated cirrhosis, we found that the SVR to DAA treatment decreased the incidence of HCC over a mean follow-up of 14 months.

Remaining clinical issues in hepatitis C treatment

Key advances in the evaluation and treatment of hepatitis C virus (HCV) infection have positively transformed the management and outcomes of those living with this chronic viral infection. Previously difficult-to-cure populations, including those coinfected with HIV infection, now enjoy similarly high success rates with interferon-free, orally administered direct-acting antiviral (DAA) therapies. Nonetheless, relevant unresolved clinical questions remain. The role and impact of viral resistance testing on treatment selection and outcome remain to be fully determined. The consequences of developing resistance while on DAA treatments that ultimately prove unsuccessful requires further evaluation. Optimal HCV management strategies in decompensated liver disease are unclear, and the role for ribavirin in DAA treatment-naïve and treatment-experienced patients is uncertain. A chief concern for those with cirrhosis relates to the risk for de novo and recurrent hepatocellular carcinoma among DAA recipients. In this article, we present and interpret current data and consider pragmatic, clinically useful options.

Levels of Cytokines in Serum Associate With Development of Hepatocellular Carcinoma in Patients With HCV Infection Treated With Direct-Acting Antivirals

Concern has arisen about the development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV) infection treated with direct-acting antivirals (DAAs). To identify patients at risk for HCC, we evaluated serum levels of immune mediators before, during, and after DAA treatment of HCV infection. Our study included 13 patients who developed HCC within 18 months after treatment (3 with HCC recurrence and 10 with new HCC) and 10 patients who did not develop HCC (controls), within at least 24 months of treatment (median, 26 months). We identified a set of 12 immune mediators (cytokines, growth factors, and apoptosis markers) whose levels were significantly higher in serum before DAA treatment of patients who eventually developed de novo HCC compared with controls. A panel of 9 cytokines, measured in serum before treatment (MIG, IL22, TRAIL, APRIL, VEGF, IL3, TWEAK, SCF, IL21), identified patients who developed de novo HCC with an area under the receiver operating characteristic curve value higher than 0.8. Further analyses of changes in levels of inflammatory cytokines during DAA treatment also provides important information about HCV-induced carcinogenesis and the effects of DAAs.

Treatment of Real-World HCV Genotype 2-Infected Japanese Patients with Sofosbuvir plus Ribavirin

The aim of this study was to characterize the treatment response and tolerability of sofosbuvir plus ribavirin therapies in Japanese patients infected with hepatitis C virus (HCV) genotype (GT)-2. This retrospective study analyzed 114 Japanese HCV GT-2 patients treated for 12 weeks with 400 mg of sofosbuvir plus weight-based ribavirin daily. This treatment led to higher sustained virologic response at 12-weeks post-treatment (SVR12) rates in both treatment-naïve and treatment-experienced patients. The efficacy of this treatment in compensated cirrhotics was the same as that in patients with chronic hepatitis. HCV GT-2a infection and lower estimated glomerular filtration rates (eGFR) tended to be associated with SVR12. Of 114 patients, 113 completed the combination of sofosbuvir plus ribavirin for 12 weeks. Seven patients without SVR12 did not have HCV NS5B-S282 mutations. The overall SVR12 rate was 90.4% (103 of 114). More effective therapeutic options with less adverse events are desired to achieve higher SVR rates in HCV GT-2 Japanese patients.