Multicentric occurrence of hepatocellular carcinoma with nonalcoholic steatohepatitis

Screening and follow-up of chronic liver diseases with understanding their etiology in clinics and hospitals

BACKGROUND AND AIM

Considering the increasing prevalence of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH), the development of an effective screening and follow-up system that enables the recognition of etiological changes by primary physicians in clinics and specialists in hospitals is required.

METHODS

Chronic hepatitis B (HBV) and C (HCV), NASH, and alcoholic steatohepatitis (ASH) patients who were assayed for Mac-2-binding protein glycosylation isomer (M2BPGi) (n = 272) and underwent magnetic resonance elastography (MRE) (n = 119) were enrolled. Patients who underwent MRE were also tested by ultrasound elastography (USE) (n = 80) and for M2BPGi (n = 97), autotaxin (ATX) (n = 62), and platelet count (n = 119), and their fibrosis-4 (FIB-4) index was calculated (n = 119).

RESULTS

FIB-4 index >2, excluding HBV-infected patients, M2BPGi >0.5, ATX >0.5, and platelet count <20 × 104/μL were the benchmark indices, and we took into consideration other risk factors, such as diabetes mellitus and age, to recommend further examinations, such as USE, based on the local situation to avoid overlooking hepatocellular carcinoma (HCC) in the clinic. During specialty care in the hospital, MRE exhibited high diagnostic ability for fibrosis stages >F3 or F4; it could efficiently predict collateral circulation with high sensitivity, which can replace USE. We also identified etiological features and found that collateral circulation in NASH/ASH patients tended to exceed high-risk levels; moreover, these patients exhibited more variation in HCC-associated liver stiffness than the HBV and HCV patients.

CONCLUSIONS

Using appropriate markers and tools, we can establish a stepwise, practical, noninvasive, and etiology-based screening and follow-up system in primary and specialty care.

Obesity and liver cancer

Obesity is an established risk factor for many types of cancers, particularly for hepatocellular carcinoma (HCC), owing to its carcinogenic potential and the association with nonalcoholic fatty liver disease (NAFLD). HCC may develop in cirrhotic and noncirrhotic livers with NAFLD, particularly in the presence of multiple metabolic risk factors such as obesity and diabetes. This issue is alarming because the population potentially at higher risk is greatly increasing. This review summarizes current evidence linking obesity and liver cancer, and discusses recent advances on the mechanisms underlying this relationship.

Should visceral fat, strictly linked to hepatic steatosis, be depleted to improve survival?

Numerous epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and its further expression, i.e., nonalcoholic fatty liver disease and death. Using novel models of visceral obesity, several studies have demonstrated that the relationship between visceral fat and longevity is causal, while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. The need of reducing the visceral fat to improve survival, mainly taking into account the strict link between nonalcoholic fatty liver disease and the coronary artery disease is discussed.

Association between nonalcoholic fatty liver disease and risk for hepatocellular cancer, based on systematic review

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) has been implicated as a cause of hepatocellular carcinoma (HCC). We performed a systematic review of epidemiology studies to confirm the association between these disorders.

METHODS

We searched PubMed for original reports published from January 1992 to December 2011 that evaluated the association between NAFLD, nonalcoholic steatohepatitis (NASH), cryptogenic cirrhosis presumed to be NASH-related, and the risk of HCC. Studies were categorized as offering potential direct evidence (eg, cohort studies) or indirect evidence (eg, case-control, cross-sectional, or case-series studies) for an association. We analyzed data from a total of 17 cohort studies (3 population based, 9 clinic based [6 limited to patients with cirrhosis], and 5 natural history), 18 case-control and cross-sectional studies, and 26 case series.

RESULTS

NAFLD or NASH cohorts with few or no cases of cirrhosis cases had a minimal risk for HCC (cumulative HCC mortality of 0%-3% for study periods up to 20 y). Cohorts with NASH and cirrhosis had a consistently higher risk (cumulative incidence ranging from 2.4% over 7 y to 12.8% over 3 y). However, the risk for HCC was substantially lower in these cohorts than for cohorts with hepatitis C-related cirrhosis. Factors that increased risk among cohorts with NASH and cirrhosis could not be determined, because most studies were not sufficiently powered for multivariate analysis.

CONCLUSIONS

This systematic review shows that despite several limitations, there is epidemiologic evidence to support an association between NAFLD or NASH and an increased risk of HCC; risk seems to be limited to individuals with cirrhosis.

Association between nonalcoholic fatty liver disease and risk for hepatocellular cancer, based on systematic review

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) has been implicated as a cause of hepatocellular carcinoma (HCC). We performed a systematic review of epidemiology studies to confirm the association between these disorders.

METHODS

We searched PubMed for original reports published from January 1992 to December 2011 that evaluated the association between NAFLD, nonalcoholic steatohepatitis (NASH), cryptogenic cirrhosis presumed to be NASH-related, and the risk of HCC. Studies were categorized as offering potential direct evidence (eg, cohort studies) or indirect evidence (eg, case-control, cross-sectional, or case-series studies) for an association. We analyzed data from a total of 17 cohort studies (3 population based, 9 clinic based [6 limited to patients with cirrhosis], and 5 natural history), 18 case-control and cross-sectional studies, and 26 case series.

RESULTS

NAFLD or NASH cohorts with few or no cases of cirrhosis cases had a minimal risk for HCC (cumulative HCC mortality of 0%-3% for study periods up to 20 y). Cohorts with NASH and cirrhosis had a consistently higher risk (cumulative incidence ranging from 2.4% over 7 y to 12.8% over 3 y). However, the risk for HCC was substantially lower in these cohorts than for cohorts with hepatitis C-related cirrhosis. Factors that increased risk among cohorts with NASH and cirrhosis could not be determined, because most studies were not sufficiently powered for multivariate analysis.

CONCLUSIONS

This systematic review shows that despite several limitations, there is epidemiologic evidence to support an association between NAFLD or NASH and an increased risk of HCC; risk seems to be limited to individuals with cirrhosis.

Hepatocellular carcinoma in non-alcoholic steatohepatitis: Growing evidence of an epidemic?

The incidence of hepatocellular carcinoma in non-viral-related chronic liver disease has gradually increased in Japan. Obesity and diabetes mellitus type 2 have been established as a significant risk factor for hepatocellular carcinoma (HCC) by epidemiologic observations and experimental studies. The risks of these factors for HCC are likely conferred by two factors: the increased risk for development of non-alcoholic steatohepatitis (NASH) and the carcinogenic potential of themselves. Hepatocellular carcinoma in NASH is difficult to evaluate because histological diagnosis is required for diagnosis of NASH, which can lead selection bias. Furthermore, end-stage NASH is in effect "burned-out" NASH, for which the diagnosis of NASH cannot be made any more. At all events, previous studies on the etiology of Japanese HCC showed that non-alcoholic fatty liver disease accounts for 1-5% of all HCC (male predominant, median age 72 years). They have high prevalences of obesity and/or diabetes mellitus type 2 and 10-75% of the HCC arose from non-cirrhotic livers. HCC in NASH may be of multicentric origin, similar to HCC based on viral hepatitis. Regular screening for HCC is extremely important especially in cirrhotic NASH patients and recurrence should be warned. In western and Asian countries, the prevalence of non-alcoholic fatty liver disease in the general population is increasing dramatically. Therefore, there is an urgent need to elucidate pathogenesis and clinical features of HCC in NASH. In this review we summarize current concepts for HCC in NASH.