Lymphoblastoid alpha-interferon in the prevention of hepatocellular carcinoma (HCC) in high-risk HbsAg-positive resected cirrhotic HCC cases: a 14-year follow-up

Interferons and their stimulated genes in the tumor microenvironment

Constitutive expression of interferons (IFNs) and activation of their signaling pathways have pivotal roles in host responses to malignant cells in the tumor microenvironment. IFNs are induced by the innate immune system and in tumors through stimulation of Toll-like receptors (TLRs) and through other signaling pathways in response to specific cytokines. Although in the oncologic context IFNs have been thought of more as exogenous pharmaceuticals, the autocrine and paracrine actions of endogenous IFNs probably have even more critical effects on neoplastic disease outcomes. Through high-affinity cell surface receptors, IFNs modulate transcriptional signaling, leading to regulation of more than 2,000 genes with varying patterns of temporal expression. Induction of the gene products by both unphosphorylated and phosphorylated STAT1 after ligand binding results in alterations in tumor cell survival, inhibition of angiogenesis, and augmentation of actions of T, natural killer (NK), and dendritic cells. The interferon-stimulated gene (ISG) signature can be a favorable biomarker of immune response but, in a seemingly paradoxical finding, a specific subset of the full ISG signature indicates an unfavorable response to DNA-damaging interventions such as radiation. IFNs in the tumor microenvironment thus can alter the emergence, progression, and regression of malignancies.

Adjuvant interferon therapy after surgical treatment for hepatitis B/C virus-related hepatocellular carcinoma: A meta-analysis

AIM

This meta-analysis aimed to determine whether interferon (IFN) therapy could improve clinical effects of patients with chronic hepatitis B virus (HBV)or hepatitis C virus (HCV) infection-related primary hepatocellular carcinoma (HCC) after surgery.

METHODS

An electronic search from January 1998 to December 2012 was conducted to identify comparative studies evaluating IFN therapy on recurrence and survival after surgical treatment of HCC.

RESULTS

The estimated odds ratios (OR) for the 1-, 2-, 3- and 5-year overall survival rates of HBV-related HCC were 3.37 (95% confidence interval [CI], 1.18-6.27), 2.36 (95% CI, 1.45-3.83), 1.81 (95% CI, 1.21-2.72) and 1.93 (95% CI, 1.35-2.75), respectively; and the OR for the 1-, 2-, 3- and 5-year recurrence rates were 0.63 (95% CI, 0.44-0.91), 0.84 (95% CI, 0.60-1.18), 0.88 (95% CI, 0.63-1.22) and 0.78 (95% CI, 0.56-1.07), respectively. The overall survival rates of HCV-related HCC were significantly higher in IFN groups than in control groups at 1, 2, 3 and 5 years (OR, 2.10; 95% CI, 0.96-4.55; OR, 1.71; 95% CI, 1.01-2.89; OR, 1.76; 95% CI, 1.09-2.83; and OR, 3.03; 95% CI, 1.97-4.65, respectively); and the recurrence rates of IFN groups were lower than control groups at 1, 2, 3 and 5 years (OR, 0.60; 95% CI, 0.38-0.92; OR, 0.57; 95% CI, 0.41-0.81; OR, 0.58; 95% CI, 0.41-0.80; and OR, 0.52; 95% CI, 0.36-0.75, respectively).

CONCLUSION

In conclusion, IFN therapy in this meta-analysis shows a significant clinical effect in postoperative patients of HCC, particularly in HCV-related HCC.

Does chemotherapy prevent HBV-related hepatocellular carcinoma? Cons

The retrospective scrutiny of studies that were originally designed to assess the antiviral activity of interferon (IFN) and nucleos(t)ide analogues (NUC) suggested reduced incidence of hepatocellular carcinoma (HCC) in responders. The interpretation of these studies, however, is questioned by the heterogeneity of patient referral, adoption of surrogate end-points, lack of control arms and, overall, by the lack of power to capture enough hard end-points of the natural history of hepatitis B, including HCC. Another point of criticism is that above all, IFN studies could have been affected by study enrolment skewed towards patients with less advanced liver disease, who had a better predicted compliance to therapy but a lower risk of developing HCC in the short-term. In my opinion, these constraints coupled with the lack of patient stratification by HCC predictors, make the evaluation of the prophylactic activity of IFN and NUC even more difficult. Overall, while single studies provide some evidence for a reduced HCC incidence in virological responders, particularly in those with moderate liver fibrosis, we still lack confirmation that anti-HBV therapy prevents HCC in patients with an established cirrhosis, too. Finally, tertiary prevention with anti-HBV treatments is controversial, due to the existence of a few, methodologically flawed studies.

Liver angiogenesis as a risk factor for hepatocellular carcinoma development in hepatitis C virus cirrhotic patients

AIM: To evaluate the predictive value of hepatocyte proliferation and hepatic angiogenesis for the occurrence of Hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) cirrhotic patients.

METHODS: One hundred-five patients (69 males, 36 females; age range, 51-90 year; median 66 year) with biopsy proven HCV cirrhosis were prospectively monitored for HCC occurrence for a median time of 64 mo. Angiogenesis was assessed by using microvessel density (MVD), hepatocyte turnover by MIB1 and PCNA indexes at inclusion in liver biopsies.

RESULTS: Forty six patients (43.8%) developed HCC after a median time of 55 (6-120) mo while 59 (56.2%) did not. Patients were divided into two groups according to the median value of each index. The difference between patients with low (median MVD = 3; range 0-20) and high (median MVD = 7; range 1-24) MVD was statistically significant (χ² = 22.06; P < 0.0001) which was not the case for MIB1 or PCNA (MIB-1: χ² = 1.41; P = 0.2351; PCNA: χ² = 1.27; P = 0.2589). The median MVD was higher in patients who developed HCC than in those who did not. HCC-free interval was significantly longer in patients with the MVD ≤ 4 (P = 0.0006). No relationship was found between MIB₁ or PCNA and MVD (MIB-1 r² = 0.00007116, P = 0.9281; PCNA: r² = 0.001950; P = 0.6692). MVD only was able to predict the occurrence of HCC in these patients. Among other known risk factors for HCC, only male sex was statistically associated with an increased risk.

CONCLUSION: Liver angiogenesis has a role for in HCV-related liver carcinogenesis and for defining patients at higher risk.

Augmentation of effects of interferon-stimulated genes by reversal of epigenetic silencing: potential application to melanoma

Increased expression of genes, silenced by methylation of their promoters, could have relevance for increasing effects of not only interferons (IFNs) but also APO2L/TRAIL, cytotoxics and immunotherapeutics for melanoma and other malignancies. A resistant melanoma cell line, A375, lacked APO2L/TRAIL or apoptosis induction by either IFN-alpha2 or IFN-beta. However, apoptosis was induced by IFNs in A375 cells by 5-aza,2'-deoxycytidine (5-Aza-dC), evaluated based upon the postulate that promoter methylation might be silencing pro-apopoptotic IFN-stimulated genes (ISGs). RASSF1A, commonly methylated at high frequency in many tumors including melanoma, which we discovered to be also an IFN-regulated gene, was increased by 5-Aza-dC. RASSF1A was important in enhancing apoptotic effects of not only IFNs and APO2L/TRAIL but also cisplatin. Unraveling epigenetic regulatory mechanisms, as yet only partially identified, will result in new biological insights and improved strategies for therapeutic use of IFNs or ISGs such as APO2L/TRAIL.

Hepatocellular carcinoma prevention: A worldwide emergence between the opulence of developed countries and the economic constraints of developing nations

Hepatocellular carcinoma (HCC) is the fifth most common neoplasm, the major cause of death in patients with liver cirrhosis, and the third most common cause of cancer-related death in the world. The geographic distribution of HCC varies significantly and 80% of cases occur in developing countries (Far East and South Asia) where the prevalence of viral hepatitis is higher. The treatment of HCC is difficult because most patients are diagnosed when the tumour is in an advanced stage and is not amenable to potential curative therapy, thus prevention is the key to reducing HCC and its related morbidity and mortality. HCC is unique among cancers, occurring mostly in patients with a known risk factor. Ninety percent of HCCs develop in the context of chronic liver diseases and mainly in patients with cirrhosis. Viral hepatitis is the most common cause of HCC worldwide, followed by alcoholic liver disease (ALD) and other causes such as non-alcoholic fatty liver disease (NAFLD), genetic haemocromatosis (GH) and primary biliary cirrhosis in an advanced stage (III-V). In certain areas of the People’s Republic of China, exposure to aflatoxin and HBV infection are thought to be responsible for the extraordinary high risk of HCC. Substantial progresses in the prevention of virusl-related hepatitis (screening of blood units, use of disposable sanitary tools, HBV vaccination) have been achieved in developed countries, but in the same areas, alcohol- and dysmetabolism-related HCCs are emerging problems which require specific interventions in terms of public health measures. In developing countries, economic constraints limit the development of any program for the prevention of viral hepatitis transmission (including health education campaigns, healthcare politics, primary prevention and the improvement of hygienic and sanitary conditions). When viral liver disease is established, only a minority of patients are treated worldwide and benefit a possible preventive effect of medical treatment on HCC development. Thus the real contribution of medical treatment to HCC prevention in patients with chronic viral hepatitis is small. Great efforts are needed to identify more effective medical measures for primary and secondary prevention of HCC.

Review: Milstein Award lecture: interferons and cancer: where from here?

Interferons (IFNs) remain the most broadly active cytokines for cancer treatment, yet ones for which the full potential is not reached. IFNs have impacted positively on both quality and quantity of life for hundreds of thousands of cancer patients with chronic leukemia, lymphoma, bladder carcinoma, melanoma, and renal carcinoma. The role of the IFN system in malignant pathogenesis continues to enhance understanding of how the IFN system may be modulated for therapeutic advantage. Reaching the full potential of IFNs as therapeutics for cancer will also result from additional understanding of the genes underlying apoptosis induction, angiogenesis inhibition, and influence on immunologic function. Food and Drug Administration (FDA) approval of IFNs occurred less than 20 years ago; after 40 years, third-generation products of early cytotoxics, such as 5- fluorouracil (5FU), are beginning to reach clinical approval. Thus, substantial potential exists for additional application of IFNs and IFN inducers as anticancer therapeutics, particularly when one considers that their pleiotropic cellular and molecular effects have yet to be fully defined.

Genotypic variability of hepatitis viruses associated with chronic infection and the development of hepatocellular carcinoma

At least five hepatitis viruses are known to date. Infection by enterically transmitted viruses (HAV and HEV) is generally benign compared with the disease caused by parenterally transmitted viruses (HBV, HCV, and HDV). Chronic infection by HBV is common and may evolve to cirrhosis and hepatocellular carcinoma (HCC). Eight HBV genotypes (A-H) have been described, with the South American genotype F being the most divergent. Seven clades of HDV have been described; among them, the South American genotype III is associated to a high frequency of fulminant hepatitis. HCV infection leads to a high rate of chronicity and HCC. From the six HCV genotypes, infection with genotype 1 might have the worst prognostic. Chronic infection by HCV and HBV is the major risk factor for HCC, which occurs, in the majority of the cases, as a consequence of cirrhosis. However, there is growing evidence that some HBV and HCV proteins might contribute to the generation of HCC. Some HBV and HCV variants and specific mutations within the viral genomes might be more frequently associated with the evolution to HCC. Although more studies are needed, emerging evidence indicates that it might be important to address the genetic variability of these viruses and their contribution to the development of HCC.