A functional polymorphism in the epidermal growth factor gene is associated with risk for hepatocellular carcinoma

Kenneth tanabe works to solve the mysteries of liver cancer: while progress has been relatively slow, this noted expert sees reasons for hope

Dr. Tanabe, Chief of the Division of Surgical Oncology at Massachusetts General Hospital, studies preventing and treating hepatocellular carcinoma, the most rapidly rising cause of cancer-related mortality. Promising developments are on the horizon.

Aberrant Cosmc genes result in Tn antigen expression in human colorectal carcinoma cell line HT-29

The Tn antigen, which arises from mutation in the Cosmc gene is one of the most common tumor associated carbohydrate antigens. Cosmc resides in X24 encoded by a single gene and functions as a specific molecular chaperone for T-synthase. While the Tn antigen cannot be detected in normal cells, Cosmc mutations inactivate T-synthase and consequently result in Tn antigen expression within certain cancers. In addition to this Cosmc mutation-induced expression, the Tn antigen is also expressed in such cell lines as Jurkat T, LSC and LS174T. Whether the Cosmc mutation is present in the colon cancer cell line HT-29 is still unclear. Here, we isolate HT-29-Tn+ cells from HT-29 cells derived from a female colon cancer patient. These HT-29-Tn+ cells show a loss of the Cosmc gene coding sequence (CDS) leading to an absence of T-synthase activity and Tn antigen expression. Additionally, almost no methylation of Cosmc CpG islands was detected in HT-29-Tn+ as well as in HT-29-Tn- and Tn- tumor cells from male patients. In contrast, the methylation frequency of CpG island of Cosmc in normal female cells was ~50%. Only one active allele of Cosmc existed in HT-29-Tn+ and HT-29-Tn- cells as based upon detection of SNP sites. These results indicate that Tn antigens expression and T-synthase inactivity in HT-29-Tn+ cells can be related to the absence of CDS in Cosmc active alleles, while an inactive allele deletion of Cosmc in HT-29 cells has no influence on Cosmc function.

Genetic risk markers for hepatocellular carcinoma in patients with alcoholic liver disease

Various single nucleotide polymorphisms have been reported to be associated with a higher risk of hepatocellular carcinoma in alcoholic cirrhotic patients. Until now, only common variants conferring a small increase in liver cancer risk have been identified. These inherited factors are able to modulate several biological pathways involved in alcohol-induced hepatocarcinogenesis, such as ethanol metabolism, inflammation, oxidative stress, or iron and lipid homeostasis. How the combination of these variants might collectively define an individual genomic risk prediction is currently being investigated. The other challenge in clinical practice lies in defining how to integrate this genetic information with other clinical parameters so as to refine selection of alcoholic cirrhotic patients according to various classes of hepatocellular carcinoma risk.

Genetic factors, viral infection, other factors and liver cancer: an update on current progress

Primary liver cancer is one of the most common cancers at the global level, accounting for half of all cancers in some undeveloped countries. This disease tends to occur in livers damaged through alcohol abuse, or chronic infection with hepatitis B and C, on a background of cirrhosis. Various cancer-causing substances are associated with primary liver cancer, including certain pesticides and such chemicals as vinyl chloride and arsenic. The strong association between HBV infection and liver cancer is well documented in epidemiological studies. It is generally acknowledged that the virus is involved through long term chronic infection, frequently associated with cirrhosis, suggesting a nonspecific mechanism triggered by the immune response. Chronic inflammation of liver, continuous cell death, abnormal cell growth, would increase the occurrence rate of genetic alterations and risk of disease. However, the statistics indicated that only about one fifth of HBV carries would develop HCC in lifetime, suggesting that individual variation in genome would also influence the susceptibility of HCC. The goal of this review is to highlight present level of knowledge on the role of viral infection and genetic variation in the development of liver cancer.

Epidermal growth factor receptor pathway polymorphisms and the prognosis of hepatocellular carcinoma

The EGFR signaling pathway is important in the control of vital processes in the carcinogenesis of hepatocellular carcinoma (HCC), including cell survival, cell cycle progression, tumor invasion and angiogenesis. In the current study, we aim to assess if genetic variants in the genes of the EGFR signaling pathway are associated with the prognosis of HCC. We genotyped 36 single nucleotide polymorphisms (SNP) in four core genes (EGF, EGFR, VEGF, and VEGFR2) by using DNA from blood samples of 363 HCC patients with surgical resection. The associations between genotypes and overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Hazard ratios (HRs) and 95% confident intervals (CIs) were estimated for the multivariate survival analyses by Cox proportional hazards regression models, adjusting for age, gender, family history, HBsAg and AFP. We found that five SNPs in the VEGFR2 gene were significantly associated with clinical outcomes of HCC patients. Among them, four SNPs (rs7692791, rs2305948, rs13109660, rs6838752) were associated with OS (p=0.035, 0.038, 0.029 and 0.028, respectively), and two SNPs (rs7692791 and rs2034965) were associated with DFS (p=0.039 and 0.017, respectively). Particularly, rs7692791 TT genotype was associated with both reduced OS (p=0.037) and DFS (p=0.043). However, only one SNP rs2034965 with the AA genotype was shown to be an independent effect on DFS (p=0.009) in the multivariate analysis. None of the other 31 polymorphisms or 9 haplotypes attained from the four genes was significantly associated with OS or DFS. Our results illustrated the potential use of VEGFR2 polymorphisms as prognostic markers for HCC patients.

Host genetics predict clinical deterioration in HCV-related cirrhosis

Single nucleotide polymorphisms (SNPs) in the epidermal growth factor (EGF, rs4444903), patatin-like phospholipase domain-containing protein 3 (PNPLA3, rs738409) genes, and near the interleukin-28B (IL28B, rs12979860) gene are linked to treatment response, fibrosis, and hepatocellular carcinoma (HCC) in chronic hepatitis C. Whether these SNPs independently or in combination predict clinical deterioration in hepatitis C virus (HCV)-related cirrhosis is unknown. We genotyped SNPs in EGF, PNPLA3, and IL28B from liver tissue from 169 patients with biopsy-proven HCV cirrhosis. We estimated risk of clinical deterioration, defined as development of ascites, encephalopathy, variceal hemorrhage, HCC, or liver-related death using Cox proportional hazards modeling. During a median follow-up of 6.6 years, 66 of 169 patients experienced clinical deterioration. EGF non-AA, PNPLA3 non-CC, and IL28B non-CC genotypes were each associated with increased risk of clinical deterioration in age, sex, and race-adjusted analysis. Only EGF non-AA genotype was independently associated with increased risk of clinical deterioration (hazard ratio [HR] 2.87; 95% confidence interval [CI] 1.31-6.25) after additionally adjusting for bilirubin, albumin, and platelets. Compared to subjects who had 0-1 unfavorable genotypes, the HR for clinical deterioration was 1.79 (95%CI 0.96-3.35) for 2 unfavorable genotypes and 4.03 (95%CI 2.13-7.62) for unfavorable genotypes for all three loci (Ptrend<0.0001). In conclusion, among HCV cirrhotics, EGF non-AA genotype is independently associated with increased risk for clinical deterioration. Specific PNPLA3 and IL28B genotypes also appear to be associated with clinical deterioration. These SNPs have potential to identify patients with HCV-related cirrhosis who require more intensive monitoring for decompensation or future therapies preventing disease progression.

Advances in research of tumor microenvironment in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is not just composed of liver cancer cells; it contains several cell types and extracellular matrix that interact with each other, creating a complex interaction network within a permissive microenvironment. The tumor microenvironment in HCC can not only support liver cancer cell growth but also promote tumor invasion through the stimulation of cancer cell proliferation, migration, and invasion and activation of angiogenesis, which together determine the phenotype of HCC. In this review, we provide an overview of current knowledge on the role of the tumor microenvironment in HCC and its application in prognosis prediction and treatment.

Hepatitis C virus-associated cancer

Hepatitis C virus (HCV) is one of the major etiologic agents of liver cancer. HCV is an RNA virus that, unlike hepatitis B virus, is unable to integrate into the host genome. Through complex interactions between viral and host proteins that induce host responses and promote inflammation, fibrosis, and ultimately cirrhosis, HCV infection can result in the development of hepatocellular carcinoma (HCC). The HCV oncogenic process involves genetic and epigenetic alterations and oncogenic effects mediated by viral proteins in the activation of cellular oncogenes, inactivation of tumor-suppressor genes, and dysregulation of multiple signal-transduction pathways. Advances in genetics and gene expression profiling have enhanced our current understanding of the pathways involved in HCV-associated liver cancer development. In this review, we summarize the current understanding of mechanisms of hepatocarcinogenesis induced by HCV infection.

A common polymorphism in the NCAN gene is associated with hepatocellular carcinoma in alcoholic liver disease

BACKGROUND & AIMS

The genetic background of alcoholic liver diseases and their complications are increasingly recognized. A common polymorphism in the neurocan (NCAN) gene, which is known to be expressed in neuronal tissue, has been identified as a risk factor for non-alcoholic fatty liver disease (NAFLD). We investigated if this polymorphism may also be related to alcoholic liver disease (ALD) and hepatocellular carcinoma (HCC).

METHODS

We analysed the distribution of the NCAN rs2228603 genotypes in 356 patients with alcoholic liver cirrhosis, 126 patients with alcoholic HCC, 382 persons with alcohol abuse without liver damage, 362 healthy controls and in 171 patients with hepatitis C virus (HCV) associated HCC. Furthermore, a validation cohort of 229 patients with alcoholic cirrhosis (83 with HCC) was analysed. The genotypes were determined by LightSNiP assays. The expression of NCAN was studied by RT-PCR and immunofluorescence microscopy.

RESULTS

The frequency of the NCAN rs2228603 T allele was significantly increased in patients with HCC due to ALD (15.1%) compared to alcoholic cirrhosis without HCC (9.3%), alcoholic controls (7.2%), healthy controls (7.9%), and HCV associated HCC (9.1%). This finding was confirmed in the validation cohort (15.7% vs. 6.8%, OR=2.53; 95%CI: 1.36-4.68; p=0.0025) and by multivariate analysis (OR=1.840; 95%CI: 1.22-2.78; p=0.004 for carriage of the rs2228603 T allele). In addition, we identified and localised NCAN expression in human liver.

CONCLUSIONS

NCAN is not only expressed in neuronal tissue, but also in the liver. Its rs2228603 polymorphism is a risk factor for HCC in ALD, but not in HCV infection.

Pathogenesis and prevention of hepatitis C virus-induced hepatocellular carcinoma

Hepatitis C virus (HCV) is one of the major aetiologic agents that causes hepatocellular carcinoma (HCC) by generating an inflammatory, fibrogenic, and carcinogenic tissue microenvironment in the liver. HCV-induced HCC is a rational target for cancer preventive intervention because of the clear-cut high-risk condition, cirrhosis, associated with high cancer incidence (1% to 7% per year). Studies have elucidated direct and indirect carcinogenic effects of HCV, which have in turn led to the identification of candidate HCC chemoprevention targets. Selective molecular targeted agents may enable personalized strategies for HCC chemoprevention. In addition, multiple experimental and epidemiological studies suggest the potential value of generic drugs or dietary supplements targeting inflammation, oxidant stress, or metabolic derangements as possible HCC chemopreventive agents. While the successful use of highly effective direct-acting antiviral agents will make important inroads into reducing long-term HCC risk, there will remain an important role for HCC chemoprevention even after viral cure, given the persistence of HCC risk in persons with advanced HCV fibrosis, as shown in recent studies. The successful development of cancer preventive therapies will be more challenging compared to cancer therapeutics because of the requirement for larger and longer clinical trials and the need for a safer toxicity profile given its use as a preventive agent. Molecular biomarkers to selectively identify high-risk population could help mitigate these challenges. Genome-wide, unbiased molecular characterization, high-throughput drug/gene screening, experimental model-based functional analysis, and systems-level in silico modelling are expected to complement each other to facilitate discovery of new HCC chemoprevention targets and therapies.

Integration of genomic information in the clinical management of HCC

Molecular profiling of hepatocellular carcinoma (HCC) is enabling the advancement of novel approaches to disease diagnosis and management. Accurate prognosis prediction in HCC is specially critical. Clinical staging systems for HCC support clinical decision-making (e.g., BCLC algorithm) might be complemented by molecular-based information in the near future. Molecular signatures derived from tumour and non-tumour samples are associated with patient recurrence an outcome. Single nucleotide polymorphisms have been linked with HCC development. Next generation sequencing studies have brought to light the genomic diversity of this disease. Gens recurrently altered in HCC and susceptible to be targeted belong to signalling pathways including telomere maintenance, cell cycle, chromatin remodelling, Wnt/beta-catenin, RAS/RAF/MAPK and PI3K/AKT/mTOR pathways. Oncogenic loops are unknown but might include some of the already discovered aberrations. Despite the intratumoral heterogeneity observed in HCC tumours, studies including large number of samples can identify key genetic drivers and contribute to the development of novel treatments and a personalized medicine.

Impact of epidermal growth factor single-nucleotide polymorphism on recurrence of hepatocellular carcinoma after hepatectomy in patients with chronic hepatitis C virus infection

Epidermal growth factor (EGF) gene single-nucleotide polymorphism (SNP) is associated with an increased risk of hepatic tumors. The study aimed to elucidate the impact of EGF SNP and EGF receptor (EGFR) expression on the recurrence of hepatocellular carcinoma (HCC) after hepatectomy. To examine the impact of EGF SNP and EGFR on recurrent HCC, we retrospectively analyzed 141 HCC patients with chronic hepatitis C virus infection who underwent curative hepatectomy. The EGF *61 GG allele was present in 69 patients (48.9%), AG in 56 (39.7%) and AA in 16 (11.4%). The AA group had a significantly lower rate of intrahepatic metastasis (0% vs 16.5%, P = 0.02), lower serum EGF concentration (26.3 ± 15.9 pg/mL vs 43.4 ± 30.5 pg/mL, P = 0.02) and lower proportion of early recurrence (≤2 years; 28.6% vs 71.2%, P = 0.03) than the AG/GG group. The AA group had significantly higher recurrence-free survival than the AG/GG group (P = 0.04), but there was no significant difference in overall survival between these two groups (P = 0.97). High versus low EGFR expression analyzed by immunohistochemical staining in cancer cells was not significantly associated with overall survival (P = 0.37) or recurrence-free survival (P = 0.39). Therefore, EGF *61 AA was associated with a lower risk of recurrence after curative hepatectomy for HCC in patients with hepatitis C virus infection than other genotypes, but EGFR expression in cancer cells was not significantly associated with prognosis.

Processes to manage analyses and publications in a phase III multicenter randomized clinical trial

Background

The timely publication of findings in peer-reviewed journals is a primary goal of clinical research. In clinical trials, the processes leading to publication can be complex from choice and prioritization of analytic topics through to journal submission and revisions. As little literature exists on the publication process for multicenter trials, we describe the development, implementation, and effectiveness of such a process in a multicenter trial.

Methods

The Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial included a data coordinating center (DCC) and clinical centers that recruited and followed more than 1,000 patients. Publication guidelines were approved by the steering committee, and the publications committee monitored the publication process from selection of topics to publication.

Results

A total of 73 manuscripts were published in 23 peer-reviewed journals. When manuscripts were closely tracked, the median time for analyses and drafting of manuscripts was 8 months. The median time for data analyses was 5 months and the median time for manuscript drafting was 3 months. The median time for publications committee review, submission, and journal acceptance was 7 months, and the median time from analytic start to journal acceptance was 18 months.

Conclusions

Effective publication guidelines must be comprehensive, implemented early in a trial, and require active management by study investigators. Successful collaboration, such as in the HALT-C trial, can serve as a model for others involved in multidisciplinary and multicenter research programs.

Trial registration

The HALT-C Trial was registered with clinicaltrials.gov (NCT00006164).

Development and validation of a clinical scoring system for predicting risk of HCC in asymptomatic individuals seropositive for anti-HCV antibodies

BACKGROUND

The development of a risk assessment tool for long-term hepatocellular carcinoma risk would be helpful in identifying high-risk patients and providing information of clinical consultation.

METHODS

The model derivation and validation cohorts consisted of 975 and 572 anti-HCV seropositives, respectively. The model included age, alanine aminotransferase (ALT), the ratio of aspirate aminotransferase to ALT, serum HCV RNA levels and cirrhosis status and HCV genotype. Two risk prediction models were developed: one was for all-anti-HCV seropositives, and the other was for anti-HCV seropositives with detectable HCV RNA. The Cox's proportional hazards models were utilized to estimate regression coefficients of HCC risk predictors to derive risk scores. The cumulative HCC risks in the validation cohort were estimated by Kaplan-Meier methods. The area under receiver operating curve (AUROC) was used to evaluate the performance of the risk models.

RESULTS

All predictors were significantly associated with HCC. The summary risk scores of two models derived from the derivation cohort had predictability of HCC risk in the validation cohort. The summary risk score of the two risk prediction models clearly divided the validation cohort into three groups (p<0.001). The AUROC for predicting 5-year HCC risk in the validation cohort was satisfactory for the two models, with 0.73 and 0.70, respectively.

CONCLUSION

Scoring systems for predicting HCC risk of HCV-infected patients had good validity and discrimination capability, which may triage patients for alternative management strategies.

Development and validation of a clinical scoring system for predicting risk of HCC in asymptomatic individuals seropositive for anti-HCV antibodies

Background

The development of a risk assessment tool for long-term hepatocellular carcinoma risk would be helpful in identifying high-risk patients and providing information of clinical consultation.

Methods

The model derivation and validation cohorts consisted of 975 and 572 anti-HCV seropositives, respectively. The model included age, alanine aminotransferase (ALT), the ratio of aspirate aminotransferase to ALT, serum HCV RNA levels and cirrhosis status and HCV genotype. Two risk prediction models were developed: one was for all-anti-HCV seropositives, and the other was for anti-HCV seropositives with detectable HCV RNA. The Cox's proportional hazards models were utilized to estimate regression coefficients of HCC risk predictors to derive risk scores. The cumulative HCC risks in the validation cohort were estimated by Kaplan-Meier methods. The area under receiver operating curve (AUROC) was used to evaluate the performance of the risk models.

Results

All predictors were significantly associated with HCC. The summary risk scores of two models derived from the derivation cohort had predictability of HCC risk in the validation cohort. The summary risk score of the two risk prediction models clearly divided the validation cohort into three groups (p<0.001). The AUROC for predicting 5-year HCC risk in the validation cohort was satisfactory for the two models, with 0.73 and 0.70, respectively.

Conclusion

Scoring systems for predicting HCC risk of HCV-infected patients had good validity and discrimination capability, which may triage patients for alternative management strategies.

Hepatocellular carcinoma: clinical frontiers and perspectives

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death and is currently the main event leading to death in patients with cirrhosis. Evolving information suggests that the metabolic syndrome with non-alcoholic liver disease may be an important cause of HCC in addition to viral hepatitis and alcohol-induced liver disease. The molecular pathogenesis is extremely complex and heterogeneous. To date the molecular information has not impacted on treatment decisions. Periodic surveillance imaging of patients with cirrhosis is widely practiced, especially because diagnostic, radiographic criteria for early-stage HCC have been defined (including nodules between 1 and 2 cm) and effective treatment is available for tumours detected at an early stage. Worldwide the approach to resection versus transplantation varies depending upon local resources, expertise and donor availability. The criteria for transplantation are discussed, and the controversial areas highlighted with evidence-based recommendations provided. Several approaches are available for intermediate stage disease, including radiofrequency ablation, transarterial chemoembolisation and radioembolisation; the rationale for these therapies is buttressed by appropriate outcome-based studies. For advanced disease, systemic therapy with sorafenib remains the option best supported by current data. Thus, while several trials have failed to improve the benefits of established therapies, studies assessing the sequential or combined application of those already known to be beneficial are needed. Also, new concepts are provided in regards to selecting and stratifying patients for second-line studies, which may help explain the failure of prior studies.

Virus associated malignancies: the role of viral hepatitis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading fatal cancer worldwide and its incidence continues to increase. Chronic viral hepatitis involving either hepatitis B virus (HBV) or hepatitis C virus (HCV) infection is the leading etiology for HCC, making HCC prevention a major goal of antiviral therapy. While recent clinical observations and translational research have enhanced our understanding of the molecular mechanisms driving the initiation and progression of HCC, much remains unknown. Current data indicates that HCC tumors are highly complex and heterogeneous resulting from the aberrant function of multiple molecular pathways. This complex biology is responsible, at least in part, for the absence of highly efficient target-directed therapies for this deadly cancer. Additionally, the direct or indirect effect of HBV and HCV infection on the development of HCC is still a contentious issue. Thus, the question remains whether viral hepatitis-associated HCC stems from virus-specific factors, and/or from a general mechanism involving inflammation and tissue regeneration. In this review we summarize general mechanisms implicated in HCC, emphasizing data generated by new technologies available today. We also highlight specific pathways by which HBV and HCV could be involved in HCC pathogenesis. However, improvements to current in vitro and in vivo systems for both viruses will be needed to rigorously define the temporal sequence and specific pathway dysregulations that drive the strong clinical link between chronic hepatitis virus infection and HCC.

The EGFR signalling system in the liver: from hepatoprotection to hepatocarcinogenesis

The liver displays an outstanding wound healing and regenerative capacity unmatched by any other organ. This reparative response is governed by a complex network of inflammatory mediators, growth factors and metabolites that are set in motion in response to hepatocellular injury. However, when liver injury is chronic, these regenerative mechanisms become dysregulated, facilitating the accumulation of genetic alterations leading to unrestrained cell proliferation and the development of hepatocellular carcinoma (HCC). The epidermal growth factor receptor (EGFR or ErbB1) signaling system has been identified as a key player in all stages of the liver response to injury, from early inflammation and hepatocellular proliferation to fibrogenesis and neoplastic transformation. The EGFR system engages in extensive crosstalk with other signaling pathways, acting as a true signaling hub for other growth factors, cytokines and inflammatory mediators. Here, we briefly review essential aspects of the biology of the EGFR, the other ErbB receptors, and their ligands in liver injury, regeneration and HCC development. Some aspects of the preclinical and clinical experience with EGFR therapeutic targeting in HCC are also discussed.

STAT3 in hepatocellular carcinoma: new perspectives

Chronic liver damage and inflammation are strong promoters of hepatocellular carcinoma (HCC) formation. HCC cells communicate with inflammatory and stromal cells via cytokine/chemokine signals. These heterotypic interactions inhibit immunologic anticancer activities and promote protumorigenic activities, such as angiogenesis or invasiveness. STAT3 mediates several reciprocal interactions between liver cancer cells and stromal cells and modulates preconditions of tumor formation such as chronic inflammation. Therefore, activation of STAT3 is considered as a tumor-promoting event in HCC formation. However, the oncogenic role of STAT3 in cancers has been challenged by several reports that suggest a tumor-suppressive activity. Here we discuss tumor-promoting and tumor-suppressive effects of cytokine-activated STAT3 in HCC.

A functional polymorphism in the epidermal growth factor gene predicts hepatocellular carcinoma risk in Japanese hepatitis C patients

BACKGROUND

A single nucleotide polymorphism (SNP) in the epidermal growth factor (EGF) gene (rs4444903) has been associated with increased risk of cancer, including hepatocellular carcinoma (HCC). The aim of this study was to examine the relationship between the EGF SNP genotype and the development and prognosis of HCC, in a Japanese population.

METHODS

Restriction fragment-length polymorphism was used to determine the presence of the EGF SNP genotype in 498 patients, including 208 patients with HCC. The level of EGF messenger ribonucleic acid (mRNA) expression in cancerous tissues was measured by quantitative reverse transcription polymerase chain reaction. The correlation between the EGF SNP genotype and prognosis was statistically analyzed in the patients with HCC.

RESULTS

The proportion of the A/A, A/G, and G/G genotypes were 5.3%, 42.8%, and 51.9%, respectively, in the patients with HCC, whereas in those without HCC, they were 8.6%, 35.9%, and 55.5%, respectively, revealing that the odds ratio (OR) of developing HCC was higher in patients with a G allele (OR =1.94, P=0.080 for A/G patients and OR =1.52, P=0.261 for G/G patients, as compared with A/A patients). In particular, when the analysis was limited to the 363 patients with hepatitis C, the OR for developing HCC was 3.54 (P=0.014) for A/G patients and was 2.85 (P=0.042) for G/G patients, as compared with A/A patients. Tumoral EGF mRNA expression in G/G patients was significantly higher than that in A/A patients (P=0.033). No statistically significant differences were observed between the EGF SNP genotype and diseasefree or overall survival.

CONCLUSION

The EGF SNP genotype might be associated with a risk for the development of HCC in Japanese patients but not with prognosis. Of note, the association is significantly stronger in patients with hepatitis C, which is the main risk factor for HCC in Japan.

Hepatocellular Carcinoma in Non-alcoholic Fatty Liver Disease: Epidemiology, Pathogenesis, and Prevention

Hepatocellular cancer (HCC) is the fifth most prevalent cancer worldwide and the third leading cause of cancer-related deaths. Non-alcoholic fatty liver disease (NAFLD), a spectrum of hepatic disorders associated with obesity and the metabolic syndrome, is a recognized risk factor for HCC. NAFLD that is advanced to cirrhosis carries the highest risk for HCC, but there is increasing concern that NAFLD-associated HCC may also occur in non-cirrhotic liver. As NAFLD is rapidly becoming the most common liver condition, it has been implicated in the worrisome trend of rising HCC incidence in a number of countries, which may offset successful measures in reducing the effect of virus-related liver cancer. Independently or in synergy with cirrhosis, NAFLD may provide a special oncogenic microenvironment through its pathogenic association with chronic nutrient excess and adipose tissue remodeling, characterized by pro-inflammatory adipokine profiles, lipotoxicity, altered hepatocellular bioenergetics, and insulin resistance. Better understanding of this complex process, and development of reliable biomarkers for HCC will be critical for early recognition and risk prediction. Moreover, correcting deranged lipid metabolism and restoring insulin sensitivity by lifestyle measures and targeted pharmacotherapy holds major promise for effective prevention of NAFLD-associated HCC.

Advanced unresectable hepatocellular carcinoma: new biologics as fresh ammunition or clues to disease understanding?

PURPOSE OF REVIEW

Hepatocellular carcinoma (HCC) is a prevalent malignancy associated with a guarded prognosis. At present, sorafenib is the only approved systemic therapy for patients with advanced disease. The effect of sorafenib on overall survival is modest and limited in time by the occurrence of drug resistance.

RECENT FINDINGS

Together with the increasing knowledge of molecular pathways involved in HCC, targeted molecules have been developed and tested in first and second line following sorafenib. These include antiangiogenic drugs, as well as biologicals inhibiting cell proliferation and survival. Recent phase III trials investigated sunitinib, linifanib, brivanib and erlotinib, but none of them were found superior to sorafenib. New findings in mechanisms of drug resistance create opportunities in the treatment of sorafenib-refractory disease, with cMET inhibition as the most promising approach. This article reviews the pathways involved in HCC and their targets as well as potential strategies for drug development in the future.

SUMMARY

Advanced HCC has been the subject of intensive clinical research following the success of sorafenib. Despite many failures, some agents show promising results in phase II trials. Targeting new pathways, using multidrug regimens and tailoring treatment guided by predictive markers should allow new successes.

Quantitative assessment of the association between MTHFR rs1801131 polymorphism and risk of liver cancer

Methylenetetrahydrofolate reductase (MTHFR) is one of the most important enzymes for folate metabolism which plays a key role in cell metabolism. MTHFR rs1801131 (A1298C) polymorphism can decrease in vitro MTHFR enzyme activity and has been hypothesized to be associated with liver cancer risk. This study aimed to quantify the strength of the association between MTHFR rs1801131 polymorphism and liver cancer risk by performing a meta-analysis. We searched the PubMed and Wanfang databases for studies relating on the association between MTHFR rs1801131 polymorphism and risk of liver cancer. Seven studies with 2,030 cases of liver cancer and 3,096 controls were finally included into the meta-analysis. Meta-analysis of a total of seven studies showed that the homozygote genotype CC of MTHFR rs1801131 polymorphism was significantly associated with decreased risk of liver cancer (for CC versus AA: odds ratio (OR) = 0.65, 95% confidence interval (CI) 0.47-0.89, P = 0.007; for CC versus AA + AC: OR = 0.65, 95% CI 0.48-0.89, P = 0.006). Subgroup by race showed that the homozygote genotype CC of MTHFR rs1801131 polymorphism was significantly associated with decreased risk of liver cancer in Asians (CC versus AA: OR = 0.64, 95% CI 0.46-0.90, P = 0.010; for CC versus AA + AC: OR = 0.63, 95% CI 0.45-0.88, P = 0.007). However, the association in Caucasians was still unclear owing to the limited data available now. Thus, Asian individuals with the homozygote genotype CC of MTHFR rs1801131 polymorphism are significantly associated with decreased risk of liver cancer. The association in Caucasians needs further studies.

Ultrasound elastography for fibrosis surveillance is cost effective in patients with chronic hepatitis C virus in the UK

BACKGROUND

Chronic hepatitis C (HCV) is a significant risk factor for cirrhosis and subsequently hepatocellular carcinoma (HCC). HCV patients with cirrhosis are screened for HCC every 6 months. Surveillance for progression to cirrhosis and consequently access to HCC screening is not standardized. Liver biopsy, the usual test to determine cirrhosis, carries a significant risk of morbidity and associated mortality. Transient ultrasound elastography (fibroscan) is a non-invasive test for cirrhosis.

PURPOSE

This study assesses the cost effectiveness of annual surveillance for cirrhosis in patients with chronic HCV and the effect of replacing biopsy with fibroscan to diagnose cirrhosis.

METHOD

A Markov decision analytic model simulated a hypothetical cohort of 10,000 patients with chronic HCV initially without fibrosis over their lifetime. The cirrhosis surveillance strategies assessed were: no surveillance; current practice; fibroscan in current practice with biopsy to confirm cirrhosis; fibroscan completely replacing biopsy in current practice (definitive); annual biopsy; annual fibroscan with biopsy to confirm cirrhosis; annual definitive fibroscan.

RESULTS

Our results demonstrate that annual definitive fibroscan is the optimal strategy to diagnose cirrhosis. In our study, it diagnosed 20 % more cirrhosis cases than the current strategy, with 549 extra patients per 10,000 accessing screening over a lifetime and, consequently, 76 additional HCC cases diagnosed. The lifetime cost is £98.78 extra per patient compared to the current strategy for 1.72 additional unadjusted life years. Annual fibroscan surveillance of 132 patients results in the diagnosis one additional HCC case over a lifetime. The incremental cost-effectiveness ratio for an annual definitive fibroscan is £6,557.06/quality-adjusted life years gained.

CONCLUSION

Annual definitive fibroscan may be a cost-effective surveillance strategy to identify cirrhosis in patients with chronic HCV, thereby allowing access of these patients to HCC screening.

Association of epidermal growth factor and epidermal growth factor receptor polymorphisms with the risk of hepatitis B virus-related hepatocellular carcinoma in the population of North China

BACKGROUND

Hepatocellular carcinoma (HCC) is a common solid malignant tumor occurring worldwide that leads to the third largest cause of death compared to other cancers. Genetic and environmental factors are involved in the pathogenesis of HCC. Epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) can stimulate the proliferation of epidermal and epithelial cells. The EGF signal pathway has a relationship with the growth of the embryo, tissue repairing, and tumorigenesis.

METHODS

In this study, 416 patients with hepatitis B virus infection (HBV)-related HCC and 645 individuals who had never been infected with HBV of the Chinese Han population were enrolled. Eight single-nucleotide polymorphisms (SNPs), whose minor allele frequency >20% in the EGF and EGFR genes, were genotyped to examine their associations with hepatocarcinogenesis. Genotyping experiments were carried out using TaqMan.

RESULTS

There were significant differences in genotype distributions (p=0.005) and allele frequencies (p=0.001, odds ratio [OR]=1.43, 95% confidence interval [CI]=1.15-1.79) of rs11569017 in the EGF gene between the HCC and control groups. After binary logistic regression to determine independent factors for susceptibility to HCC under an additive model, rs11569017 was still independently associated with the susceptibility to HCC (p=0.021, OR=1.48, 95% CI=1.06-2.07), but no significant differences in other SNPs were found. Additionally, the haplotype T-G constructed by rs11569017 and rs4444903 of the EGF gene might increase the risk of HBV-related HCC (p=0.002, OR=1.44, 95% CI=1.15-1.82).

CONCLUSION

The rs11569017 T allele was associated with susceptibility to HBV-related HCC.

Prognostic gene expression signature for patients with hepatitis C-related early-stage cirrhosis

BACKGROUND & AIMS

Cirrhosis affects 1% to 2% of the world population and is the major risk factor for hepatocellular carcinoma (HCC). Hepatitis C cirrhosis-related HCC is the most rapidly increasing cause of cancer death in the United States. Noninvasive methods have been developed to identify patients with asymptomatic early-stage cirrhosis, increasing the burden of HCC surveillance, but biomarkers are needed to identify patients with cirrhosis who are most in need of surveillance. We investigated whether a liver-derived 186-gene signature previously associated with outcomes of patients with HCC is prognostic for patients with newly diagnosed cirrhosis but without HCC.

METHODS

We performed gene expression profile analysis of formalin-fixed needle biopsy specimens from the livers of 216 patients with hepatitis C-related early-stage (Child-Pugh class A) cirrhosis who were prospectively followed up for a median of 10 years at an Italian center. We evaluated whether the 186-gene signature was associated with death, progression of cirrhosis, and development of HCC.

RESULTS

Fifty-five (25%), 101 (47%), and 60 (28%) patients were classified as having poor-, intermediate-, and good-prognosis signatures, respectively. In multivariable Cox regression modeling, the poor-prognosis signature was significantly associated with death (P = .004), progression to advanced cirrhosis (P < .001), and development of HCC (P = .009). The 10-year rates of survival were 63%, 74%, and 85% and the annual incidence of HCC was 5.8%, 2.2%, and 1.5% for patients with poor-, intermediate-, and good-prognosis signatures, respectively.

CONCLUSIONS

A 186-gene signature used to predict outcomes of patients with HCC is also associated with outcomes of patients with hepatitis C-related early-stage cirrhosis. This signature might be used to identify patients with cirrhosis in most need of surveillance and strategies to prevent the development of HCC.

Mitogenic insulin receptor-A is overexpressed in human hepatocellular carcinoma due to EGFR-mediated dysregulation of RNA splicing factors

Insulin receptor (IR) exists as two isoforms resulting from the alternative splicing of IR pre-mRNA. IR-B promotes the metabolic effects of insulin, whereas IR-A rather signals proliferative effects. IR-B is predominantly expressed in the adult liver. Here, we show that the alternative splicing of IR pre-mRNA is dysregulated in a panel of 85 human hepatocellular carcinoma (HCC) while being normal in adjacent nontumor liver tissue. An IR-B to IR-A switch is frequently observed in HCC tumors regardless of tumor etiology. Using pharmacologic and siRNA approaches, we show that the autocrine or paracrine activation of the EGF receptor (EGFR)/mitogen-activated protein/extracellular signal-regulated kinase pathway increases the IR-A:IR-B ratio in HCC cell lines, but not in normal hepatocytes, by upregulating the expression of the splicing factors CUGBP1, hnRNPH, hnRNPA1, hnRNPA2B1, and SF2/ASF. In HCC tumors, there is a significant correlation between the expression of IR-A and that of splicing factors. Dysregulation of IR pre-mRNA splicing was confirmed in a chemically induced model of HCC in rat but not in regenerating livers after partial hepatectomy. This study identifies a mechanism responsible for the generation of mitogenic IR-A and provides a novel interplay between IR and EGFR pathways in HCC. Increased expression of IR-A during neoplastic transformation of hepatocytes could mediate some of the adverse effects of hyperinsulinemia on HCC.

Role of the microenvironment in the pathogenesis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and the third greatest cause of cancer-related death worldwide, and its incidence is increasing. Despite the significant improvement in management of HCC over the past 30 years, there are no effective chemoprevention strategies, and only one systemic therapy has been approved for patients with advanced tumors. This drug, sorafenib, acts on tumor cells and the stroma. HCC develops from chronically damaged tissue that contains large amounts of inflammation and fibrosis, which also promote tumor progression and resistance to therapy. Increasing our understanding of how stromal components interact with cancer cells and the signaling pathways involved could help identify new therapeutic and chemopreventive targets.

Genetic polymorphisms of epidermal growth factor in relation to risk of hepatocellular carcinoma: two case-control studies

BACKGROUND

Earlier, we reported a highly statistically significant association between T-helper 1 (Th1) and Th2 cytokine genotypes and hepatocellular carcinoma (HCC) risk among natives of southern Guangxi, China, a hyperendemic region for HCC. Epidermal growth factor (EGF) plays a critical role in malignant transformation of hepatocytes and tumor progression. A polymorphism in the EGF gene (61A > G) results in elevation of EGF in liver tissues and blood. Epidemiological data are sparse on the possible association between EGF genetic polymorphism and HCC risk.

METHODS

The EGF 61A > G polymorphism, multiple Th1 and Th2 genotypes, and environmental risk factors for HCC were determined on 117 HCC cases and 225 healthy control subjects among non-Asians of Los Angeles County, California, a low-risk population for HCC, and 250 HCC cases and 245 controls of southern Guangxi, China.

RESULTS

Following adjustment for all known or suspected HCC risk factors, non-Asians in Los Angeles who possessed at least one copy of the high activity 61*G allele of the EGF gene showed a statistically non-significant, 78% increased risk of HCC compared with those possessing the EGF A/A genotype. This EGF-HCC risk association significantly strengthened among heavy users of alcohol [odds ratio (OR) = 3.44, 95% confidence interval (CI) = 0.93-12.76, P = 0.065)], and among individuals carrying the high-risk Th1/Th2 genotypes for HCC (OR = 3.34, 95% CI = 1.24-9.03, P = 0.017). No association between EGF genotype and HCC risk was observed among Chinese in southern Guangxi, China.

CONCLUSION

Genetic polymorphism in the EGF gene resulting in elevated level of EGF, may contribute to HCC risk among low-risk non-Asians in Los Angeles.

Pathogenic mechanisms in HBV- and HCV-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal cancer, with increasing worldwide incidence, that is mainly associated with chronic hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections. There are few effective treatments partly because the cell- and molecular-based mechanisms that contribute to the pathogenesis of this tumour type are poorly understood. This Review outlines pathogenic mechanisms that seem to be common to both viruses and which suggest innovative approaches to the prevention and treatment of HCC.

Genetic signatures in choline and 1-carbon metabolism are associated with the severity of hepatic steatosis

Choline metabolism is important for very low-density lipoprotein secretion, making this nutritional pathway an important contributor to hepatic lipid balance. The purpose of this study was to assess whether the cumulative effects of multiple single nucleotide polymorphisms (SNPs) across genes of choline/1-carbon metabolism and functionally related pathways increase susceptibility to developing hepatic steatosis. In biopsy-characterized cases of nonalcoholic fatty liver disease and controls, we assessed 260 SNPs across 21 genes in choline/1-carbon metabolism. When SNPs were examined individually, using logistic regression, we only identified a single SNP (PNPLA3 rs738409) that was significantly associated with severity of hepatic steatosis after adjusting for confounders and multiple comparisons (P=0.02). However, when groupings of SNPs in similar metabolic pathways were defined using unsupervised hierarchical clustering, we identified groups of subjects with shared SNP signatures that were significantly correlated with steatosis burden (P=0.0002). The lowest and highest steatosis clusters could also be differentiated by ethnicity. However, unique SNP patterns defined steatosis burden irrespective of ethnicity. Our results suggest that analysis of SNP patterns in genes of choline/1-carbon metabolism may be useful for prediction of severity of steatosis in specific subsets of people, and the metabolic inefficiencies caused by these SNPs should be examined further.

Hepatitis C virus and hepatocarcinogenesis

Hepatitis C virus (HCV) is an RNA virus that is unable to integrate into the host genome. However, its proteins interact with various host proteins and induce host responses. The oncogenic process of HCV infection is slow and insidious and probably requires multiple steps of genetic and epigenetic alterations, the activation of cellular oncogenes, the inactivation of tumor suppressor genes, and dysregulation of multiple signal transduction pathways. Stellate cells may transdifferentiate into progenitor cells and possibly be linked to the development of hepatocellular carcinoma (HCC). Viral proteins also have been implicated in several cellular signal transduction pathways that affect cell survival, proliferation, migration and transformation. Current advances in gene expression profile and selective messenger RNA analysis have improved approach to the pathogenesis of HCC. The heterogeneity of genetic events observed in HCV-related HCCs has suggested that complex mechanisms underlie malignant transformation induced by HCV infection. Considering the complexity and heterogeneity of HCCs of both etiological and genetic aspects, further molecular classification is required and an understanding of these molecular complexities may provide the opportunity for effective chemoprevention and personalized therapy for HCV-related HCC patients in the future. In this review, we summarize the current knowledge of the mechanisms of hepatocarcinogenesis induced by HCV infection.

Cytokines are associated with postembolization fever and survival in hepatocellular carcinoma patients receiving transcatheter arterial chemoembolization

OBJECTIVE

Cytokines play important roles in angiogenesis, inflammation, and cell growth. The present study aimed to investigate the correlation between cytokine changes and clinical characteristics in hepatocellular carcinoma (HCC) patients receiving transcatheter arterial chemoembolization (TACE).

METHODS

Forty-one TACE-näive HCC patients receiving 73 sessions of TACE and 30 healthy controls were studied. Serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiogenin, epidermal growth factor (EGF), epidermal growth factor receptor, and transforming growth factor β1 (TGF-β1) before and at 1, 3, 5, 7, and 14 days after TACE as well as clinical parameters were analyzed.

RESULTS

Baseline serum levels of VEGF, bFGF, IL-6, IL-8, and TNF-α in HCC patients were significantly elevated, whereas EGF and TGF-β1 levels were lower compared to those in healthy controls (p < 0.05 for all). Serum IL-6 increased rapidly and peaked on day 1 after TACE administration, whereas VEGF increased more slowly and peaked on day 14 after TACE administration. Patients with post-TACE fever had higher serum IL-6 levels on days 1, 3, and 5 (p < 0.005 for all). Patients with pre-TACE serum VEGF < 200 pg/ml had a longer survival than those with pre-TACE serum VEGF levels ≥ 200 pg/ml (22.2 months vs. 11.6 months, p = 0.014). Cox multivariate analysis showed that baseline serum VEGF significantly predicted survival for HCC patients receiving TACE.

CONCLUSIONS

TACE is associated with the modulation of serum angiogenic, inflammatory, and cell growth cytokines in HCC patients. Serum IL-6 correlates with post-TACE fever, and baseline serum VEGF independently predicts patient survival.

Prevention of hepatocellular carcinoma: potential targets, experimental models, and clinical challenges

Chronic fibrotic liver diseases such as viral hepatitis eventually develop liver cirrhosis, which causes occurrence of hepatocellular carcinoma (HCC). Given the limited therapeutic efficacy in advanced HCC, prevention of HCC development could be an effective strategy for improving patient prognosis. However, there is still no established therapy to meet the goal. Studies have elucidated a wide variety of molecular mechanisms and signaling pathways involved in HCC development. Genetically-engineered or chemically-treated experimental models of cirrhosis and HCC have been developed and shown their potential value in investigating molecular therapeutic targets and diagnostic biomarkers for HCC prevention. In this review, we overview potential targets of prevention and currently available experimental models, and discuss strategies to translate the findings into clinical practice.

Surveillance for hepatocellular carcinoma

The only hope for a cure from hepatocellular carcinoma (HCC) rests on early diagnosis as it can be attained through semiannual surveillance with abdominal ultrasound (US) of patients at risk. While the strategy of semiannual screening rests on the growth rate of the tumor that in cirrhotic patients takes 6 months to double its volume, on average, the noninvasive radiological diagnosis of HCC is possible in cirrhotic patients with a de novo HCC and patients with chronic hepatitis B. More recently, metabolic diseases related to insulin resistance, including diabetes and obesity, have been recognized to be causally related to HCC as well, in most patients bridging HCC to the histopathological diagnosis of non-alcoholic steatohepatitis (NASH). While the endpoint of an early diagnosis is achieved quite easily in most patients with >1 cm HCC by computed tomography (CT) or magnetic resonance imaging (MRI) demonstrating the specific pattern of an intense contrast uptake during the arterial phase (wash-in) and contrast wash-out during the venous/delayed phase, nodules <1 cm in size are more difficult to diagnose, almost invariably requiring an enhanced follow up with three monthly examinations with US until they grow in size or change their echo pattern. Owing to the lack of robust controlled evidence demonstrating a clinical benefit of surveillance, the real support for screening for liver cancer comes from the striking differences in response to therapy between screened populations in whom HCC is diagnosed and treated at early stages and patients with more advanced, incidentally detected tumors. This notwithstanding, numerous barriers work against screening effectiveness, including limited or outdated knowledge, lack of financial incentives, and limited access to appropriate testing and treatment. Though strengthening prediction in individual patients is expected to improve the cost-effectiveness ratio of screening, the benefits of approaches like pretreatment patient stratification by clinical, histologic, and genetic scores remain uncertain, while the worthiness of excluding patients with severe comorbidities and aged individuals is still debated.

Single nucleotide polymorphisms and risk of hepatocellular carcinoma in cirrhosis

Liver carcinogenesis is a complex and multi-factorial process, in which both environmental and genetic features interfere and contribute to malignant transformation. Patients with cirrhosis are particularly exposed and justify periodical screenings in order to detect the early development of hepatocellular carcinoma (HCC). The risk of HCC is, however, not identical from one patient to another. The identification of host factors that may also play an important role in HCC development may improve our understanding of the implications of the various biological pathways involved in liver carcinogenesis; such progress may as well help refine the selection of patients who could benefit from specific preventative measures or could be given adapted screening policies. Numerous candidate-gene studies have reported associations between single nucleotide polymorphisms (SNPs) and the presence of HCC. Some of these publications unfortunately suffer from major methodological drawbacks because of their case-control, retrospective and monocentric aspect. Prospective cohort studies conducted in large homogeneous populations and comprising a sufficient number of events during follow-up may overcome these pitfalls, but require a long time to be conducted and are still scarce. More recently, the first Genome Wide Association studies (GWAs) have enabled the identification of unsuspected loci that may be involved in various steps implicated in liver tumourigenesis. Taken together, these studies highlight variants that modulate oxidative stress, iron metabolism, inflammatory and immune responses, DNA repair mechanisms or systems involved in cell-cycle regulation as genetic traits susceptible to modify the natural history of cirrhotic patients and partly explain the observed differences in the risk of HCC occurrence. However, large genetic epidemiology studies in the field of cancer diseases have suggested the limited ability of polymorphic traits, alone, to refine individual prognosis. The integration of various panels of genes into clinical scores may in the near future define a "genomic risk prediction" specific to liver cancer developed in cirrhotic patients.

Epidermal growth factor 61A>G polymorphism is associated with risk of hepatocellular carcinoma: a meta-analysis

The association between hepatocellular carcinoma (HCC) and the 61A>G polymorphism in the epidermal growth factor (EGF) gene has been analyzed in several studies, but results have been inconsistent. The aim of this study was to integrate previous findings and explore whether this polymorphism is associated with susceptibility to HCC. A meta-analysis was performed by searching PubMed, Web of Science, and Cochrane Library databases. Data were extracted using predefined form and pooled odds ratios (OR) with 95% confidence intervals (CI) and were calculated to evaluate the strength of this association. Five studies involving 690 cases, 514 healthy controls, and 1419 controls with cancer-free liver diseases were identified. On the basis of healthy controls, the significant main effects on HCC risk were observed in a heterozygote comparison (OR=1.76, 95% CI 1.07-2.90, p=0.02) and a dominant genetic model (OR=1.65, 95% CI 1.03-2.66, p=0.04). On the basis of the controls with cancer-free liver diseases, a significantly increased risk of HCC was found in all the genetic models. Subgroup analyses stratified by ethnicity and etiology of HCC also showed positive associations. The EGF 61G allele is a risk factor for developing HCC without the influence of ethnic and etiological diversity.

Functional genomic studies: insights into the pathogenesis of liver cancer

Liver cancer is the sixth-most-common cancer overall but the third-most-frequent cause of cancer death. Among primary liver cancers, hepatocellular carcinoma (HCC), the major histological subtype, is associated with multiple risk factors, including hepatitis B and C virus infection, alcohol consumption, obesity, and diet contamination. Although previous studies have revealed that certain genetic and epigenetic changes, such as TP53 and β-catenin mutations, occur in HCC cells, the pathogenesis of this cancer remains obscure. Functional genomic approaches-including genome-wide association studies, whole-genome and whole-exome sequencing, array-based comparative genomic hybridization, global DNA methylome mapping, and gene or noncoding RNA expression profiling-have recently been applied to HCC patients with different clinical features to uncover the genetic risk factors and underlying molecular mechanisms involved in this cancer's initiation and progression. The genome-wide analysis of germline and somatic genetic and epigenetic events facilitates understanding of the pathogenesis and molecular classification of liver cancer as well as the identification of novel diagnostic biomarkers and therapeutic targets for cancer.

Association of epidermal growth factor +61 A/G polymorphism in Chinese patients with colon cancer

Epidermal growth factor (EGF) plays an important role in tumorigenesis. The association between the +61 A/G polymorphism of the EGF gene and colon cancer risk remains controversial and unclear. The objective of this study was to investigate the association between EGF +61 A/G polymorphism and colon cancer risk in a Chinese population. A hospital-based case-control study was conducted to assess the possible association between EGF +61 A/G polymorphism and colon cancer risk. A total of 180 colon cancer patients and 180 cancer-free healthy controls were recruited in the Chinese population. Genomic DNA was isolated from peripheral blood, and gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Colon cancer patients had a significantly higher frequency of +61 GG genotype (odds ratio [OR]=1.93, 95% confidence interval [CI]=1.07, 3.50; p=0.03) than that of controls. When stratified by the tumor location, tumor size, growth pattern, differentiation, and tumor-node-metastasis (TNM) stage of colon cancer, no statistically significant results were observed. Our study revealed that EGF +61 GG genotype was associated with a higher risk of colon cancer in Chinese population.

Epidermal growth factor gene polymorphism and risk of hepatocellular carcinoma: a meta-analysis

BACKGROUND

Hepatocarcinogenesis is a complex process that may be influenced by many factors, including polymorphism in the epidermal growth factor (EGF) gene. Previous work suggests an association between the EGF 61*A/G polymorphism (rs4444903) and susceptibility to hepatocellular carcinoma (HCC), but the results have been inconsistent. Therefore, we performed a meta-analysis of several studies covering a large population to address this controversy.

METHODS

PubMed, EMBASE, Google Scholar and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. Data were abstracted independently by two reviewers. A meta-analysis was performed to examine the association between EGF 61*A/G polymorphism and susceptibility to HCC. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Eight studies were chosen in this meta-analysis, involving 1,304 HCC cases (1135 Chinese, 44 Caucasian and 125 mixed) and 2,613 controls (1638 Chinese, 77 Caucasian and 898 mixed). The EGF 61*G allele was significantly associated with increased risk of HCC based on allelic contrast (OR = 1.29, 95% CI = 1.16-1.44, p<0.001), homozygote comparison (OR = 1.79, 95% CI = 1.39-2.29, p<0.001) and a recessive genetic model (OR = 1.34, 95% CI = 1.16-1.54, p<0.001), while patients carrying the EGF 61*A/A genotype had significantly lower risk of HCC than those with the G/A or G/G genotype (A/A vs. G/A+G/G, OR = 0.66, 95% CI = 0.53-0.83, p<0.001).

CONCLUSION

The 61*G polymorphism in EGF is a risk factor for hepatocarcinogenesis while the EGF 61*A allele is a protective factor. Further large and well-designed studies are needed to confirm this conclusion.

Genomic risk of hepatitis C-related hepatocellular carcinoma

To identify the genetic susceptibility factor(s) for hepatitis C virus-induced hepatocellular carcinoma (HCV-induced HCC), we conducted a genome-wide association study using 432,703 autosomal SNPs in 721 individuals with HCV-induced HCC (cases) and 2890 HCV-negative controls of Japanese origin. Eight SNPs that showed possible association (P <1 10(⁻5)) in the genome-wide association study were further genotyped in 673 cases and 2596 controls. We found a previously unidentified locus in the 50 flanking region of MICA on 6p21.33 (rs2596542, P(combined) = 4.21 10(⁻13), odds ratio = 1.39) to be strongly associated with HCV induced HCC. Subsequent analyses using individuals with chronic hepatitis C (CHC) indicated that this SNP is not associated with CHC susceptibility (P = 0.61) but is significantly associated with progression from CHC to HCC (P = 3.13 10(⁻8)). We also found that the risk allele of rs2596542 was associated with lower soluble MICA protein levels in individuals with HCV-induced HCC (P = 1.38 10(⁻13)).

Targeted therapy for hepatocellular carcinoma: novel agents on the horizon

Hepatocellular carcinoma (HCC) is the most common liver cancer, accounting for 90% of primary liver cancers. In the last decade it has become one of the most frequently occurring tumors worldwide and is also considered to be the most lethal of the cancer systems, accounting for approximately one third of all malignancies. Although the clinical diagnosis and management of early-stage HCC has improved significantly, HCC prognosis is still extremely poor. Furthermore, advanced HCC is a highly aggressive tumor with a poor or no response to common therapies. Therefore, new effective and well-tolerated therapy strategies are urgently needed. Targeted therapies have entered the field of anti-neoplastic treatment and are being used on their own or in combination with conventional chemotherapy drugs. Molecular-targeted therapy holds great promise in the treatment of HCC. A new therapeutic opportunity for advanced HCC is the use of sorafenib (Nexavar). On the basis of the recent large randomized phase III study, the Sorafenib HCC Assessment Randomized Protocol (SHARP), sorafenib has been approved by the FDA for the treatment of advanced HCC. Sorafenib showed to be able to significantly increase survival in patients with advanced HCC, establishing a new standard of care. Despite this promising breakthrough, patients with HCC still have a dismal prognosis, as it is currently the major cause of death in cirrhotic patients. Nevertheless, the successful results of the SHARP trial underscore the need for a comprehensive understanding of the molecular pathogenesis of this devastating disease. In this review we summarize the most important studies on the signaling pathways implicated in the pathogenesis of HCC, as well as the newest emerging drugs and their potential use in HCC management.

ABO blood group and the risk of hepatocellular carcinoma: a case-control study in patients with chronic hepatitis B

BACKGROUND

Studies have observed an association between the ABO blood group and risk of certain malignancies. However, no studies of the association with hepatocellular carcinoma (HCC) risk are available. We conducted this hospital-based case-control study to examine the association with HCC in patients with chronic hepatitis B (CHB).

METHODS

From January 2004 to December 2008, a total of 6275 consecutive eligible patients with chronic hepatitis B virus (HBV) infection were recruited. 1105 of them were patients with HBV-related HCC and 5,170 patients were CHB without HCC. Multivariate logistic regression models were used to investigate the association between the ABO blood group and HCC risk.

RESULTS

Compared with subjects with blood type O, the adjusted odds ratio (AOR) for the association of those with blood type A and HCC risk was 1.39 [95% confidence interval (CI), 1.05-1.83] after adjusting for age, sex, type 2 diabetes, cirrhosis, hepatitis B e antigen, and HBV DNA. The associations were only statistically significant [AOR (95%CI) = 1.56(1.14-2.13)] for men, for being hepatitis B e antigen positive [AOR (95%CI) = 4.92(2.83-8.57)], for those with cirrhosis [AOR (95%CI), 1.57(1.12-2.20)], and for those with HBV DNA≤10(5)copies/mL [AOR (95%CI), 1.58(1.04-2.42)]. Stratified analysis by sex indicated that compared with those with blood type O, those with blood type B also had a significantly high risk of HCC among men, whereas, those with blood type AB or B had a low risk of HCC among women.

CONCLUSIONS

The ABO blood type was associated with the risk of HCC in Chinese patients with CHB. The association was gender-related.