Ju Dong Yang

Hepatocellular carcinoma: a global view

Hepatocellular carcinoma (HCC) is a global health problem, although developing countries are disproportionally affected: over 80% of HCCs occur in such regions. About three-quarters of HCCs are attributed to chronic HBV and HCV infections. In areas endemic for HCV and HBV, viral transmission occurs at an early age, and infected individuals develop HCC in mid-adulthood. As these are their most productive years of life, HCC accounts for a substantial burden on the health-care system and drain of productive capacity in the low-income and middle-income countries most affected by HCV and HBV infections. Environments with disparate resource levels require different strategies for the optimal management of HCC. In high-resource environments, guidelines from the American Association for the Study of Liver Diseases or European Association for the Study of the Liver should be applied. In intermediate-resource or low-resource environments, the fundamental focus should be on primary prevention of HCC, through universal HBV vaccination, taking appropriate precautions and antiviral treatments. In intermediate-resource and low-resource environments, the infrastructure and capacity for abdominal ultrasonography, percutaneous ethanol injection, radiofrequency ablation and surgical resection should be established. Programs to provide targeted therapy at low cost, similar to the approach used for HIV therapy in the developing world, should be pursued.

The tumor microenvironment in hepatocellular carcinoma: current status and therapeutic targets.

A growing body of literature highlights the cross-talk between tumor cells and the surrounding peri-tumoral stroma as a key modulator of the processes of hepatocarcinogenesis, epithelial mesenchymal transition (EMT), tumor invasion and metastasis. The tumor microenvironment can be broadly classified into cellular and non-cellular components. The major cellular components include hepatic stellate cells, fibroblasts, immune, and endothelial cells. These cell types produce the non-cellular components of the tumor stroma, including extracellular matrix (ECM) proteins, proteolytic enzymes, growth factors and inflammatory cytokines. The non-cellular component of the tumor stroma modulates hepatocellular carcinoma (HCC) biology by effects on cancer signaling pathways in tumor cells and on tumor invasion and metastasis. Global gene expression profiling of HCC has revealed that the tumor microenvironment is an important component in the biologic and prognostic classification of HCC. There are substantial efforts underway to develop novel drugs targeting tumor-stromal interactions. In this review, we discuss the current knowledge about the role of the tumor microenvironment in pathogenesis of HCC, the role of the tumor microenvironment in the classification of HCC and efforts to develop treatments targeting the tumor microenvironment.

Epidemiology and Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major world health problem because of the high incidence and case fatality rate. In most patients, the diagnosis of HCC is made at an advanced stage, which limits the application of curative treatments. Most HCCs develop in patients with underlying chronic liver disease. Chronic viral hepatitis B and C are the major causes of liver cirrhosis and HCC. Recent improvements in treatment of viral hepatitis and in methods for surveillance and therapy for HCC have contributed to better survival of patients with HCC. This article reviews the epidemiology, cause, prevention, clinical manifestations, surveillance, diagnosis, and treatment approach for HCC.

Cirrhosis Is Present in Most Patients With Hepatitis B and Hepatocellular Carcinoma

BACKGROUND & AIMS There are few data available about the prevalence or effects of cirrhosis in patients with hepatocellular carcinoma (HCC) from viral hepatitis. We compared patients with HCC and hepatitis B virus (HBV) or hepatitis C virus (HCV) infections to determine the proportions of cirrhosis in each group, virologic and tumor characteristics, and overall survival. METHODS This analysis included patients with HBV (n = 64) or HCV (n = 118) infection who were diagnosed with HCC at the Mayo Clinic in Rochester, Minnesota from 1994-2008; groups were matched for age and sex. The diagnosis of cirrhosis was based on histology and, if histologic information was insufficient or unavailable, clinical indicators that included ascites or varices, thrombocytopenia or splenomegaly, and radiographic configuration of cirrhosis. Virologic characteristics, tumor stage, and patient survival were also assessed. RESULTS The prevalence of histologic cirrhosis was 88% among patients with HBV infection and 93% among those with HCV infection (P = .46). When the most inclusive criteria for cirrhosis were applied, cirrhosis was present in 94% of patients with HBV and 97% with HCV (P = .24). Among HCV patients, 5.2% were negative for HCV RNA after antiviral treatment; 63.4% of HBV patients had HBV DNA <2000 IU/mL with or without treatment. Patients with HBV tended to have less surveillance and more advanced stages of HCC, without differences in survival from those with HCV infection (P = .75). CONCLUSIONS Most patients with HCC and chronic viral hepatitis had evidence of cirrhosis, including those with HBV infection and those without active viral replication.

Factors That Affect Risk for Hepatocellular Carcinoma and Effects of Surveillance

BACKGROUND & AIMS The incidence of hepatocellular carcinoma (HCC) in the United States is increasing. Surveillance may affect the stage at diagnosis and consequently the treatment options available for HCC. We evaluated risk factors for HCC, the proportion of cases detected via surveillance, tumor characteristics, treatment approaches, and overall patient survival in a referral center cohort. METHODS The study included all patients diagnosed with HCC at the Mayo Clinic, Rochester, Minnesota, from 2007 to 2009 (n = 460). Clinical information was retrospectively abstracted from the medical record. RESULTS Hepatitis C virus (HCV, 36%), alcohol use (29%), and nonalcoholic fatty liver disease (NAFLD, 13%) were the most common risk factors for HCC. HCV was present in 56% of patients younger than 60. NAFLD was present in 19% of patients older than 60. HCC was detected during surveillance in 31% of patients. Patients with worse liver function were more likely to be on surveillance. Transarterial chemoembolization, surgical resection, and liver transplantation were the most common treatment approaches for HCC. Patients diagnosed with HCC during surveillance had less advanced disease, were more likely to be eligible for potentially curative treatments, and had increased survival times (P < .001). CONCLUSIONS At a major US referral center, the predominant HCC etiologies were HCV, alcohol use, and NAFLD. HCCs were detected during surveillance in the minority of patients. HCCs detected during surveillance were of less advanced stage, and patients were more likely to receive treatment that prolonged their survival.

Gender and Menopause Impact Severity of Fibrosis among Patients with Nonalcoholic Steatohepatitis

Estrogens inhibit stellate cell activation and fibrogenesis. Thus, gender and reproductive states may influence the degree of fibrosis in patients with nonalcoholic steatohepatitis (NASH). To investigate the association between gender, menopause, and the severity of liver fibrosis in patients with NASH, we analyzed 541 adult patients enrolled from our Duke Liver Clinics (n = 338) and the Duke Metabolic and Weight Loss Surgery Program (n = 203) who had a histologic diagnosis of NASH. Multiple ordinal logistic regression models were used to assess the association between gender, menopause, and severity of liver fibrosis. Overall, men, premenopausal, and postmenopausal women composed 35.1%, 28.4%, and 36.5% of the population, respectively. The mean age was 48 years and 22% had advanced fibrosis. After adjusting for covariates (enrolling site, grades of portal inflammation, and hepatocyte ballooning) and potential confounders (race, body mass index, diabetes/prediabetes, hypertension), adjusted cumulative odd ratio (ACOR) and 95% confidence interval (CI) for greater fibrosis severity was 1.4 (0.9, 2.1) (P = 0.17) for postmenopausal women and 1.6 (1.0, 2.5) (P = 0.03) for men, having premenopausal women as a reference. There was borderline interaction between gender and age group divided by age 50, the average age at menopause in the U.S. (P = 0.08): ACOR and 95% CI of having greater fibrosis severity in men compared to women was 1.8 (1.1, 2.9) for patients with age <50 years (P = 0.02) and 1.2 (0.7, 2.1) for patients with age ≥50 years (P = 0.59). Conclusion: Men are at a higher risk of having more severe fibrosis compared to women before menopause, while postmenopausal women have a similar severity of liver fibrosis compared to men. These findings may be explained by the protective effects of estrogen against fibrogenesis. (Hepatology 2014;59:1406‐1414)

Risk factors for intrahepatic cholangiocarcinoma: Association between metformin use and reduced cancer risk

The associations between diabetes, smoking, obesity, and intrahepatic cholangiocarcinoma (ICC) risk remain inconclusive. Metformin is purportedly associated with a reduced risk for various cancers. This case‐control study evaluated risk factors for ICC and explored the effects of metformin on ICC risk in a clinic/hospital‐based cohort. ICC patients observed at the Mayo Clinic (Rochester, MN) between January 2000 and May 2010 were identified. Age, sex, ethnicity, and residential area‐matched controls were selected from among Mayo Clinic Biobank participants. The associations between potential factors and ICC risk were determined. Six hundred and twelve cases and 594 controls were identified. Factors associated with increased ICC risk included biliary tract diseases (adjusted odds ratio [AOR]: 81.8; 95% confidence interval [CI]: 11.2‐598.8; P < 0.001), cirrhosis (AOR, 8.0; 95% CI: 1.8‐36.5; P = 0.007), diabetes (AOR, 3.6; 95% CI: 2.3‐5.5; P < 0.001), and smoking (AOR, 1.6; 95% CI: 1.3‐2.1; P < 0.001). Compared to diabetic patients not treated with metformin, the odds ratio (OR) for ICC for diabetic patients treated with metformin was significantly decreased (OR, 0.4; 95% CI: 0.2‐0.9; P = 0.04). Obesity and metabolic syndrome were not associated with ICC. Conclusion: This study confirmed diabetes and smoking as independent risk factors for ICC. A novel finding was that treatment with metformin was significantly associated with a 60% reduction in ICC risk in diabetic patients. (HEPATOLOGY 2013)

Neuropilin-1 stimulates tumor growth by increasing fibronectin fibril assembly in the tumor microenvironment.

The tumor microenvironment, including stromal myofibroblasts and associated matrix proteins, regulates cancer cell invasion and proliferation. Here, we report that neuropilin-1 (NRP-1) orchestrates communications between myofibroblasts and soluble fibronectin that promote α5β1 integrin-dependent fibronectin fibril assembly, matrix stiffness, and tumor growth. Tumor growth and fibronectin fibril assembly were reduced by genetic depletion or antibody neutralization of NRP-1 from stromal myofibroblasts in vivo. Mechanistically, the increase in fibronectin fibril assembly required glycosylation of serine 612 of the extracellular domain of NRP-1, an intact intracellular NRP-1 SEA domain, and intracellular associations between NRP-1, the scaffold protein GIPC, and the nonreceptor tyrosine kinase c-Abl that augmented α5β1 fibronectin fibril assembly activity. Analysis of human cancer specimens established an association between tumoral NRP-1 levels and clinical outcome. Our findings indicate that NRP-1 activates the tumor microenvironment, thereby promoting tumor growth. These results not only identify new molecular mechanisms of fibronectin fibril assembly but also have important implications for therapeutic targeting of the myofibroblast in the tumor microenvironment.

Integrative Genomic Analysis of Cholangiocarcinoma Identifies Distinct IDH-Mutant Molecular Profiles

Summary Cholangiocarcinoma (CCA) is an aggressive malignancy of the bile ducts, with poor prognosis and limited treatment options. Here, we describe the integrated analysis of somatic mutations, RNA expression, copy number, and DNA methylation by The Cancer Genome Atlas of a set of predominantly intrahepatic CCA cases and propose a molecular classification scheme. We identified an IDH mutant-enriched subtype with distinct molecular features including low expression of chromatin modifiers, elevated expression of mitochondrial genes, and increased mitochondrial DNA copy number. Leveraging the multi-platform data, we observed that ARID1A exhibited DNA hypermethylation and decreased expression in the IDH mutant subtype. More broadly, we found that IDH mutations are associated with an expanded histological spectrum of liver tumors with molecular features that stratify with CCA. Our studies reveal insights into the molecular pathogenesis and heterogeneity of cholangiocarcinoma and provide classification information of potential therapeutic significance.

Risk prediction of hepatocellular carcinoma in patients with cirrhosis: The ADRESS-HCC risk model

All patients with cirrhosis are at risk of developing hepatocellular carcinoma (HCC). This risk is not uniform because other patient‐related factors influence the risk of HCC. The objective of the current study was to develop an HCC risk prediction model to estimate the 1‐year probability of HCC to assist with patient counseling.