Trends in hepatocellular carcinoma due to non-alcoholic fatty liver disease

Introduction: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and is associated with hepatocellular carcinoma (HCC), the most frequent malignant liver tumor. The increasing prevalence of obesity and diabetes is influencing the epidemiology of HCC with the most dramatic increases in NAFLD-related HCC seen in Western countries. Although cirrhosis is the major risk factor for HCC in NAFLD, there is increasing recognition that NAFLD-HCC occurs in the absence of cirrhosis.

Areas covered: The epidemiology of NAFLD related HCC and its impact on changing the incidence of HCC globally. We overview risk factors for NAFLD-HCC in the presence and absence of cirrhosis and examine trends in liver transplantation (LT) related to NAFLD-HCC.

Expert commentary: The incidence of NAFLD-related cirrhosis will continue to rise globally in parallel with risk factors of obesity and diabetes. Consequently, NAFLD-related HCC will become an increasingly important cause of liver-related morbidity and mortality and a common indication for LT worldwide. Further identification of risk factors for NAFLD-HCC and effective treatments for NAFLD are required to reduce this future burden of disease.     

Non‐alcoholic fatty liver disease: a review of epidemiology,risk factors,diagnosis and management

Due to the rising prevalence of obesity and type II diabetes mellitus, non‐alcoholic fatty liver disease is becoming the leading cause of chronic liver disease in the Western world. In some patients, simple steatosis can result in non‐alcoholic steatohepatitis which over time can lead to liver cirrhosis and its associated sequelae, including hepatocellular carcinoma. Early identification and management of patients at risk with intensive dietary and lifestyle modification are essential to prevent the development of advanced liver disease and its complications. In this review, we will discuss the epidemiology of non‐alcoholic fatty liver disease, pathogenesis, diagnosis, management and surveillance strategies to offset the morbidity and mortality of this disease, as well as liver and non‐liver‐related complications.     

Non-alcoholic fatty liver disease: an overview

Non-alcoholic fatty liver disease (NAFL) includes a spectrum of clinicopathological conditions with increasing prevalence in the developed world. Although steatosis alone seems to have a benign course, those patients with the diagnosis of non-alcoholic steatohepatitis (NASH) can have a progressive course. Additionally, there is now evolving, indirect evidence that some of the patients with cryptogenic cirrhosis may be the result of 'burned-out' NASH. Although NAFL and NASH are associated with insulin-resistance syndrome, some patients with NAFL may have no obvious risk factors. Despite preliminary data from a number of pilot studies, no established therapies can be offered to patients with NASH. Over the next few years, a number of exciting research projects dealing with the epidemiology as well as the pathogenesis of NAFL are expected to be completed. It is anticipated that, through a better understanding of NAFL, more effective treatment protocols can be developed targeting only those patients with NASH that are at the highest risk for progression to cirrhosis and liver failure.     

Gut microbiota dysbiosis in patients with non-alcoholic fatty liver disease

BACKGROUND: Gut microbiota plays a significant role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). This study aimed to assess the contribution of gut microbiota dysbiosis to the pathogenesis of NAFLD. METHODS: Forty-seven human feces samples (25 NAFLD patients and 22 healthy subjects) were collected and 16S rDNA amplicon sequencing was conducted on Hiseq 2000 platform. Discrepancy of species composition between controls and NAFLD group was defined by Metastats analysis under P value<0.01. RESULTS: NAFLD patients harbored lower gut microbiota diversity than healthy subjects did. In comparison to the control group, the Proteobacteria (13.50%) and Fusobacteria (2.76%) phyla were more abundant in NAFLD patients. Ad-ditionally, the Lachnospiraceae (21.90%), Enterobacteriaceae (12.02%), Erysipelotrichaceae (3.83%), and Streptococcaceae (1.39%) families, as well as the Escherichia_Shigella (10.84%), Lachnospiraceae_Incertae_Sedis (7.79%), and Blautia (4.95%) genera were enriched in the NAFLD group. However, there was a lower abundance of Prevotella in the NAFLD group than that in the control group (5.83% vs 27.56%, P<0.01). The phylum Bacteroidetes (44.63%) also tended to be more abundant in healthy subjects, and the families Prevotellaceae (28.66%) and Ruminococcaceae (26.44%) followed the same trend. Compared to those without non-alcoholic steatohepa-titis (NASH), patients with NASH had higher abundance of genus Blautia (5.82% vs 2.25%; P=0.01) and the correspond-ing Lachnospiraceae family (24.33% vs 14.21%; P<0.01). Patients with significant fibrosis had a higher abundance of genus Escherichia_Shigella (12.53% vs 1.97%; P<0.01) and the corresponding Enterobacteriaceae family (13.92% vs 2.07%;P<0.01) compared to those with F0/F1 fibrosis. CONCLUSIONS: NAFLD patients and healthy subjects harbor varying gut microbiota. In contrast to the results of previous research on children, decreased levels of Prevotella might be detrimental for adults with NAFLD. The increased level of the genus Blautia, the family Lachnospiraceae, the genus Escherichia_Shigella, and the family Enterobacteriaceae may be a primary contributor to NAFLD progression.     

Protein glutathionylation increases in the liver of patients with non-alcoholic fatty liver disease

Background and Aim:  Oxidative stress is an important pathophysiological mechanism in non-alcoholic steatohepatitis, where hepatocyte apoptosis is significantly increased correlating with disease severity. Protein glutathionylation occurs as a response to oxidative stress, where an increased concentration of oxidized glutathione modifies post-translational proteins by thiol disulfide exchange. In this study, we analyzed the protein glutathionylation in non-alcoholic fatty liver disease (NAFLD) and evaluated a potential association between glutathionylation, fibrosis, and vitamin E treatment.
Methods:  Protein glutathionylation was studied in the livers of 36 children (mean age 12.5 years, range 4–16 years) subdivided into three groups according to their NAFLD activity score (NAS) by Western blot analysis and immunohistochemistry, using a specific monoclonal antibody. In addition, we identified the hepatocyte ultrastructures involved in glutathionylation by immunogold electron microscopy.
Results:  Our findings showed that protein glutathionylation increases in the livers of patients with NAFLD and it is correlated with steatohepatitis and liver fibrosis. Its increase appears mainly in nuclei and cytosol of hepatocytes, and it is reversed by antioxidant therapy with reduced fibrosis.
Conclusion:  Protein glutathionylation significantly increases in livers with NAFLD, strongly suggesting that oxidative injury plays a crucial role in this disease. Furthermore, the marked increase of protein glutathionylation, in correlation with collagen VI immunoreactivity, suggests a link between the redox status of hepatic protein thiols and fibrosis.     

Influence of inducible nitric oxide synthase polymorphisms in Japanese patients with non-alcoholic fatty liver disease

Aim:  Genetic factors as well as environmental factors play an important role in the development of non-alcoholic fatty liver disease (NAFLD). Recently, inducible nitric oxide synthase (iNOS) was significantly higher in the severest form of non-alcoholic steatohepatitis (NASH), and nitric oxide (NO) has been determined to play an important role in the process of fibrosis in NASH. In this study, we investigated iNOS gene polymorphisms for associations with NAFLD.
Methods:  A total of 115 NAFLD patients, consisting of 65 patients with NASH and 50 patients with simple steatosis, in whom a positive diagnosis had been made by liver biopsy, and 435 healthy control subjects, were recruited into this study.
Results:  We investigated 10 single nucleotide polymorphisms (SNP) of the iNOS gene, one of which, rs1060822, had the lowest P -value in the allele frequency model ( P  = 0.00078) with an odds ratio (95% confidence interval) of 0.49 (0.32–0.75). Four SNP, rs2297510, rs2297511, rs2797512 and rs1060822, were significantly associated with NAFLD, even when the most conservative Bonferroni's correction was applied. Linkage disequilibrium analysis revealed that SNP rs1060822 and three other SNP, rs2297510, rs2297511 and rs2797512, were in the same block. We also investigated associations between rs1060822 genotypes and the fibrosis index, and the results of the analysis revealed an additive increase in the fibrosis index and intrahepatic iNOS mRNA expression in the patients with the T allele of rs1060822.
Conclusion:  This is the first study to identify genetic variations in iNOS that may influence the risk of NAFLD and liver fibrosis in NAFLD.     

脂肪肝与非脂肪肝患者血常规的差异分析

目的探讨成人脂肪肝患者与非脂肪肝患者血常规的差异。方法选用沈阳地区2008年3月～2008年12月参加体检的18岁以上人群为研究对象,对肝脏彩色多普勒检查诊断的脂肪肝与非脂肪肝患者,采用问卷咨询、体格检查和生化检查外,重点探讨脂肪肝与血常规之间的关系,数据用SPSS16.0软件分析。结果入选人群共8842名,B超共检出脂肪肝3306例,占37.39%,其中酒精性、非酒精性脂肪肝分别占15%（1326名）和22.39%（1980名）,与非脂肪肝组（NAFL）相比,脂肪肝组（AFL）WBC（白细胞计数）、EO%（嗜酸性细胞比率）、RBC（红细胞计数）、HGB（血红蛋白浓度）、HCT（红细胞比积测定）、MCH（平均红细胞Hb含量）、MCHC（平均红细胞Hb浓度）、RDW（红细胞分布宽度）、PDW（血小板分布宽度）显著增加（P〈0.01）;LYM%（淋巴细胞比率）、MONO%（单核细胞比率）、MCV（平均细胞容积）、P-LCR（大型血小板比率）、MPV（平均血小板体积）等明显增加（P〈0.05）;PLT（血小板计数）明显减少（P〈0.05）;与非酒精性脂肪肝组（NAFL）比,酒精性脂肪肝（AFL）组RBC、HGB、HCT、MCV、MCHC等显著增加（P〈0.01）,LYM%明显减少（P〈0.05）,MCH、MONO%（单核细胞比率）明显增加（P〈0.05）。结论脂肪肝患者中白细胞总数及分类（除中性粒细胞百分比外）明显高于非脂肪肝组,红细胞系统（除MCHC外）也有类似的趋势,而血小板计数明显低于非脂肪肝组;而酒精性和非酒精性脂肪肝相比,红细胞系统显著增加,尤其MCV更加明显,而白细胞系统（除LYM%明显减少外）和血小板系统大部分无显著变化。说明简单的血常规及分类检查对脂肪肝的临床诊断和病因诊断具有重要的意义。     

Clinical features and outcomes of cirrhosis due to non-alcoholic steatohepatitis compared with cirrhosis caused by chronic hepatitis C

Background and Aim:  Ethnic differences in non-alcoholic steatohepatitis (NASH) are well-documented, but there has been no study on the prognosis of Japanese NASH patients with cirrhosis. Accordingly, we compared cirrhotic NASH with liver cirrhosis caused by chronic hepatitis C (LC-C) to clarify its clinical features and define the risk factors for death.
Methods:  A prospective evaluation of the outcomes of NASH patients with severe fibrosis was started in 1990. Data on age- and sex-matched patients with biopsy-proven LC-C were collected retrospectively and used as the control.
Results:  There were 68 patients with cirrhotic NASH and 69 with LC-C. The Child–Turcotte–Pugh (CTP) class was similar in these two groups. Although the outcome of the NASH group was better than that of the LC-C group, cirrhotic NASH followed a similar course to that of LC-C; that is, complications of cirrhosis developed, including hepatocellular carcinoma (HCC; the 5-year HCC rate was 11.3% for NASH and 30.5% for HCV) and death (the 5-year survival rates were 75.2% and 73.8%, respectively). HCC was the leading cause of death in both groups (NASH, 47%; HCV, 68%). The occurrence of HCC and the CTP class were significant risk factors for mortality in NASH patients according to a multivariate analysis (HCC: hazard ratio [HR] 7.96, 95% confidence interval [CI] 2.45–25.88, CTP class A: HR 0.17, 95% CI 0.06–0.50).
Conclusion:  In conclusion, the present study confirmed that cirrhotic NASH has a similar course to LC-C. The occurrence of HCC was the strongest predictor of mortality in the NASH groups. These findings may be helpful when deciding on therapeutic interventions for NASH and also for the daily management of these patients.     

Pathogenesis of hepatocarcinogenesis in non-cirrhotic nonalcoholic fatty liver disease:Potential mechanistic pathways

Although hepatocellular carcinoma(HCC) primarily arises in the background of liver cirrhosis,the development of HCC in nonalcoholic fatty liver disease(NAFLD) without cirrhosis is increasingly recognized. The pathogenesis of NAFLD associated non-cirrhotic HCC is distinct from that of cirrhotic HCC because the metabolic syndrome(MS) along with obesity and insulin resistance(IR) underlie several unique mechanisms that promote tumorigenesis. IR associated with MS,NAFLD,and type 2 diabetes mellitus lead to the release of multiple pro-inflammatory cytokines,including tumor necrosis factor alpha,interleukin-6,leptin and resistin,as well as decreased amounts of adiponectin. These processes favor the development of hepatic steatosis and inflammation within the liver,which precede HCC development. Nevertheless,further investigation is necessary to elucidate the determinants for development of HCC in patients with NAFLD in the absence of cirrhosis.     

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the Western world. It is closely associated with metabolic syndrome. The alarming epidemics of diabetes and obesity have fueled an increasing prevalence of NAFLD, particularly among these high-risk groups. Histologically, NAFLD encompasses a disease spectrum ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), which is characterized by hepatocyte injury, inflammation, and variable degrees of fibrosis on liver biopsy. Non-alcoholic steatohepatitis can progress to cirrhosis in a fraction of patients. There is currently little understanding of risk factors for disease progression and the disease pathogenesis has not been fully defined. Liver biopsy remains the gold standard for diagnosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. There are no well-established pharmacological agents for treatment of NASH, although this is a subject of ongoing research.     

Hepatocellular carcinoma in patients with non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease(NAFLD) is the most common chronic liver disease in the United States and represents an increasingly important etiology of hepatocellular carcinoma(HCC) with annual cumulative incidence rates ranging from 2% to 12% in cohorts of NAFLD cirrhosis. While the risk of progression of NAFLD to HCC remains higher among patients with fibrosis or cirrhosis, an increasing amount of literature describes NAFLD-HCC as a disease that can occur in the absence of cirrhosis. Efforts to characterize the pathogenesis of NAFLD-HCC have suggested mechanisms that strongly associate with states of hyperinsulinemia and chronic inflammation, cellular mechanisms including adaptive immune responses and hepatic progenitor cell populations, and genetic polymorphisms including mutations of PNPLA3. Current literature describes NAFLD-HCC mostly as a disease of late presentation with lower rates of receipt of curative therapy and worse prognosis. However, a growing body of evidence has reported comparable and potentially more favorable disease-free and overall survival rates among patients with NAFLD-HCC after receipt of curative treatment. This review summarizes current evidence of epidemiology, pathophysiology, disease presentation, demand and receipt of curative therapy, post-treatment outcomes, and overall survival of NAFLD-associated HCC.     

The characteristics and natural history of Japanese patients with nonalcoholic fatty liver disease.

AIMS: The aim of our study was to elucidate the characteristics and natural history of Japanese nonalcoholic fatty liver disease (NAFLD). PATIENTS AND METHODS: Two hundred and forty-seven patients were diagnosed as having biopsy-proven NAFLD at Tokyo Women's Medical University or an affiliated hospital from 1990 to June 2004. Biopsies were scored for the severity of steatosis, necro-inflammation, and fibrosis according to modified Brunt criteria. We assessed the clinicopathological features and natural history of NAFLD in patients stratified by the stage of their fibrosis. Univariate and multivariate logistic analyses were performed, and the diagnostic ability was assessed by the area under the receiver operating characteristic curve. RESULTS: Clinicopathological features: The median age of the patients was 53 years, with a range from 10 to 89 years. There were 130 males and 117 females. Histologically, 46 patients were classified as F3 (bridging fibrosis), and 43 patients had F4 (cirrhosis). Females and older patients were more common in the F3-4 patients. Most of the F3-4 patients showed mild elevation of transaminases with significant deterioration of liver function tests compared with F0-2 patients. Ten patients were simultaneously diagnosed as having cirrhotic NASH and hepatocellular carcinoma (HCC). Natural history: During follow-up (median 44 months) of the F3-4 patients, 10 patients developed liver-related morbidity and five patients developed HCC. In the F3-4 patients, the 5-year cumulative incidence of HCC was 20%. Eight patients died (two of liver failure, four of HCC and two of other carcinomas). Serum markers for detecting F3-4: Serum hyaluronic acid levels can accurately evaluate NAFLD patients with F3-4. CONCLUSIONS: The most important consequence of NAFLD patients with advanced fibrosis was HCC. Regular screening for this complication is extremely important.     

细胞衰老在非酒精性脂肪性肝病发生发展中的作用

非酒精性脂肪性肝病(NAFLD)是一种非酒精原因所致的以肝细胞脂肪变性为主要特征的临床病理综合征,肝硬化及肝细胞癌是NAFLD的两个最为重要的肝病结局。细胞衰老是细胞脱离正常周期不可逆地丧失增殖能力后进入的一种相对稳定的状态,是细胞生命活动的一种客观规律。研究表明细胞衰老与NAFLD肝纤维化进程及肝细胞癌变的发生发展密切相关,为NAFLD相关肝硬化及肝细胞癌的防治提供了一个新的思路。     

Difference in malignancies of chronic liver disease due to non-alcoholic fatty liver disease or hepatitis C in Japanese elderly patients

Aim: Malignancies that include hepatocellular carcinoma often occurred in patients with chronic liver disease. The aim of this retrospective match control study was to assess the cumulative development incidence and predictive factors for total malignancies in elderly Japanese patients with non‐alcoholic hepatic diseases (NAFLD) or hepatitis C virus (HCV). Methods: A total of 1600 NAFLD patients with age of ≥60 years were enrolled, and 1600 HCV patients with age of ≥60 years were selected as control by matching 1:1 with NAFLD group for age, sex, and follow‐up period. The primary goal is the first development of malignancies. Evaluation was performed by the use of the Wilcoxon rank sum test, the Kaplan–Meier method, and Cox proportional hazard model. The mean observation period is 8.2 years in both NAFLD and HCV group, respectively. Results: The number of patients with the development of malignancies was 167 in the NAFLD group and 395 in the HCV group. The 10th development rate of malignancies was 13.9% in the NAFLD group and 28.2% in the HCV group (risk ratio 2.27; P < 0.001). The incident rates of hepatocellular carcinoma in all the malignancies were 6.0% (10/167) in the NAFLD group and 67.6% (267/395) in the HCV group (P < 0.001). The malignancies in the NAFLD group were observed in the following order: gastric cancer 34 cases (20.4%) > colon cancer 31 cases (18.6%) > prostate cancer 21 cases (12.6%). Conclusions: The incident rates of hepatocellular carcinoma in all the malignancies were approximately 6% in the NAFLD group and two‐thirds in the HCV group.     

Clinical usage of serum ferritin to assess liver fibrosis in patients with non‐alcoholic fatty liver disease: Proceed with caution

Serum ferritin was recently reported to have low diagnostic accuracy for the detection of advanced fibrosis in patients with non‐alcoholic fatty liver disease (NAFLD). To corroborate these findings, we investigated the diagnostic accuracy of serum ferritin levels for detecting liver fibrosis in NAFLD patients utilizing a large Japanese cohort database. A total 1201 biopsy‐proven NAFLD patients, seen between 2001 and 2013, were enrolled into the Japan Study Group of NAFLD. Analysis was performed on data from this cohort comparing between serum ferritin levels and hepatic histology. Serum ferritin increased with increasing histological grade of steatosis, lobular inflammation and ballooning. Multivariate analyses revealed that sex differences, steatotic grade and fibrotic stage were independently associated with serum ferritin levels (P < 0.0001, <0.0001, 0.0248, respectively). However, statistical analyses performed using serum ferritin levels demonstrated that the area under the receiver–operator curve for detecting fibrosis was not adequate for rigorous prediction. Several factors including sex differences, steatosis and fibrosis were found to correlate with serum ferritin levels. Therefore, serum ferritin may have low diagnostic accuracy for specifically detecting liver fibrosis in NAFLD patients due to the involvement of multiple hepatocellular processes.