Systemic treatment of hepatocellular carcinoma secondary to nonalcoholic fatty liver disease

Hepatocellular carcinoma(HCC)is the third leading cause of cancer death globally,with 15%of cases arising on a background of non-alcoholic fatty liver disease(NAFLD).NAFLD is a heterogenous condition ranging from fatty liver to cirrhosis and is itself a growing global problem,with estimated worldwide prevalence of 50%in 2040.Pathophysiology of NAFLD-HCC is not well understood,there are no dedicated screening programs,and there have been no clinical studies of anticancer treatments in this population specifically.However,the NAFLD-HCC population appears different than other aetiologies-patients tend to be older,diagnosed at more advanced stages,have more comorbidities,and overall worse prognosis.Understanding of best treatment options for this group of patients is an urgent unmet clinical need.This narrative review discusses NAFLD-HCC pathophysiology and systemic treatment,and offers suggestions for future directions in this therapy area.

Characteristics of hepatocellular carcinoma in cirrhotic and non-cirrhotic non-alcoholic fatty liver disease

AIM: To determine characteristics and prognosticpredictors of patients with hepatocellular carcinoma(HCC) in association with non-alcoholic fatty liver disease(NAFLD).METHODS: We reviewed the records of all patients with NAFLD associated HCC between 2000 and 2012. Data collected included demographics; histology; presence or absence of cirrhosis, size and number of HCC, alpha-fetoprotein, body mass index(BMI), and the presence of diabetes, hypertension, or dyslipidaemia.RESULTS: Fifty-four patients with NAFLD associated HCC were identified. Mean age was 64 years with 87% male. Fifteen percent(8/54) were not cirrhotic. 11%, 24% and 50% had a BMI of < 25 kg/m2, 25-29 kg/m2 and ≥ 30 kg/m2 respectively. Fifty-nine percent were diabetic, 44% hypertensive and 26% hyperlipidaemic. Thirty-four percent of the patients had ≤ 1 of these risk factors. Non-cirrhotics had a significantly larger mean tumour diameter at diagnosis than cirrhotics(P = 0.041). Multivariate analysis did not identify any other patient characteristics that predicted the size or number of HCC.CONCLUSION: HCC can develop in NAFLD without cirrhosis. At diagnosis such tumours are larger than those in cirrhotics, conferring a poorer prognosis.

Epidemic of non-alcoholic fatty liver disease and hepatocellular carcinoma

Non-alcoholic fatty liver disease(NAFLD) associated hepatocellular carcinoma(HCC) incidence is increasing worldwide, paralleling the obesity epidemic. Although most cases are associated with cirrhosis, HCC can occur without cirrhosis in NAFLD. Diabetes and obesity are associated risk factors for HCC in patients. Given the sheer magnitude of the underlying risk factors(diabetes, obesity, non-cirrhotic NAFLD) screening for HCC in the non-cirrhotic population is not recommended. Optimal screening strategies in NAFLD cirrhosis are not completely elucidated with Ultrasound having significant limitations in detection of liver lesions in the presence of obesity and steatosis. Consequently NAFLD-HCC is more often diagnosed at a later stage with larger tumors and reduced opportunities for curative treatments as opposed to HCC in other causes of cirrhosis. When HCC is found at a curative stage treatments including liver transplantation, resection and loco-regional therapies are associated with good results similar to that seen in HCV-HCC. Future strategies under study include the use of chemopreventive and antioxidant agents to reduce development of cirrhosis and non-alcoholic steatohepatitis(NASH). Strategies to reverse NASH via weight loss, control of associated conditions like diabetes are key strategies in reducing the increasing incidence of NASH-HCC. Novel therapeutic agents for NASH are in trials and if successful in achieving reversal of NASH will be an important strategy in reducing NAFLD-HCC.

Fibroblast growth factor signaling in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis:Paving the way to hepatocellular carcinoma

Metabolic disorders are increasingly leading to non-alcoholic fatty liver disease,subsequent steatohepatitis,cirrhosis and hepatocellular carcinoma.Fibroblast growth factors and their receptors play an important role in maintaining metabolic homeostasis also in the liver and disorders in signaling have been identified to contribute to those pathophysiologic conditions leading to hepatic lipid accumulation and chronic inflammation.While specific and well tolerated inhibitors of fibroblast growth factor receptor activity are currently developed for(non-liver)cancer therapy,treatment of non-alcoholic fatty liver disease and nonalcoholic steatohepatitis is still limited.Fibroblast growth factor-mimicking or restoring approaches have recently evolved as a novel therapeutic option and the impact of such interactions with the fibroblast growth factor receptor signaling network during non-alcoholic fatty liver disease/non-alcoholic steatohepatitis development is reviewed here.

Non-alcoholic fatty liver disease and hepatocellular carcinoma:Clinical challenges of an intriguing link

Non-alcoholic fatty liver disease(NAFLD)has emerged as the most common liver disorder worldwide mainly attributed to the epidemic spread of obesity and type 2 diabetes mellitus.Although it is considered a benign disease,NAFLD can progress to non-alcoholic steatohepatitis,liver cirrhosis and hepatocellular carcinoma(HCC).Most data regarding the epidemiology of NAFLD-related HCC are derived from cohort and population studies and show that its incidence is increasing as well as it is likely to emerge as the leading indication for liver transplantation,especially in the Western World.Although cirrhosis constitutes the main risk factor for HCC development,in patients with NAFLD,HCC can arise in the absence of cirrhosis,indicating specific carcinogenic molecular pathways.Since NAFLD as an underlying liver disease for HCC is often underdiagnosed due to lack of sufficient surveillance in this population,NAFLDHCC patients are at advanced HCC stage at the time of diagnosis making the management of those patients clinically challenging and affecting their prognostic outcomes.In this current review,we summarize the latest literature on the epidemiology,other than liver cirrhosis-pathogenesis,risk factors and prognosis of NAFLD-HCC patients.Finally,we emphasize the prevention of the development of NAFLD-associated HCC and we provide some insight into the open questions and issues regarding the appropriate surveillance policies for those patients.

Non-alcoholic fatty liver disease-related hepatocellular carcinoma:Is there a role for immunotherapy?

Hepatocellular carcinoma(HCC)is among the most common cancers and it is a major cause of cancer-related deaths.Non-alcoholic fatty liver disease(NAFLD)affects approximately one fourth of individuals worldwide and it is becoming one of the most important causes of HCC.The pathogenic mechanisms leading to NAFLD-related HCC are complex and not completely understood.However,metabolic,fibrogenic,oncogenic,inflammatory and immunological pathways seem to be involved.First-line therapy of advanced HCC has recently undergone major changes,since the combination of atezolizumab and bevacizumab was proven to increase survival when compared to sorafenib.Other immune-oncology drugs are also demonstrating promising results in patients with advanced HCC when compared to traditional systemic therapy.However,initial studies raised concerns that the advantages of immunotherapy might depend on the underlying liver disease,which seems to be particularly important in NAFLD-related HCC,as these tumors might not benefit from it.This article will review the mechanisms of NAFLD-related hepatocarcinogenesis,with an emphasis on its immune aspects,the efficacy of traditional systemic therapy for advanced NAFLD-related HCC,and the most recent data on the role of immunotherapy for this specific group of patients,showing that the management of this condition should be individualized and that a general recommendation cannot be made at this time.

Hepatocellular carcinoma in non-alcoholic steatohepatitis without cirrhosis

Cirrhosis is an emerging major cause of the development of hepatocellular carcinoma(HCC),but in non-alcoholic fatty liver disease(NAFLD),up to 50%of patients with HCC had no clinical or histological evidence of cirrhosis.It is currently challenging to propose general recommendations for screening patients with NAFLD without cirrhosis,and each patient should be evaluated on a caseby-case basis based on the profile of specific risk factors identified.For HCC screening in NAFLD,a valid precision-based screening is needed.Currently,when evaluating this population of patients,the use of non-invasive methods can guide the selection of those who should undergo a screening and surveillance program.Hence,the objective of the present study is to review the epidemiology,the pathophysiology,the histopathological aspects,the current recommendations,and novel perspectives in the surveillance of non-cirrhotic NAFLD-related HCC.

Non-alcoholic fatty liver disease:An expanded review

Non-alcoholic fatty liver disease(NAFLD) encompasses the simple steatosis to more progressive steatosis with associated hepatitis, fibrosis, cirrhosis, and in some cases hepatocellular carcinoma. NAFLD is a growing epidemic, not only in the United States, but worldwide in part due to obesity and insulin resistance leading to liver accumulation of triglycerides and free fatty acids. Numerous risk factors for the development of NAFLD have been espoused with most having some form of metabolic derangement or insulin resistance at the core of its pathophysiology. NAFLD patients are at increased risk of liver-related as well as cardiovascular mortality, and NAFLD is rapidly becoming the leading indication for liver transplantation. Liver biopsy remains the gold standard for definitive diagnosis, but the development of noninvasive advanced imaging, biochemical and genetic tests will no doubt provide future clinicians with a great deal of information and opportunity for enhanced understanding of the pathogenesis and targeted treatment. As it currently stands several medications/supplements are being used in the treatment of NAFLD; however, none seem to be the "magic bullet" in curtailing this growing problem yet. In this review we summarized the current knowledge of NAFLD epidemiology, risk factors, diagnosis, pathogenesis, pathologic changes, natural history, and treatment in order to aid in further understanding this disease and better managing NAFLD patients.

Obesity and non-alcoholic fatty liver disease: Disparate associations among asian populations

obesity is a global epidemic contributing to an increas-ing prevalence of obesity-related systemic disorders, including nonalcoholic fatty liver disease. The rising prevalence of nonalcoholic steatohepatitis(NASh) will in the near future lead to end-stage liver disease in a large cohort of patients with NASh-related cirrhosis and NASh is predicted to be a leading indication for liver transplantation in the coming decade. however, the prevalence of obesity and the progression of hepatic histological damage associated with NASh exhibit sig-nificant ethnic disparities. Despite a significantly lower body mass index and lower rates of obesity compared to other ethnic groups, Asians continue to demonstrate a significant prevalence of hypertension, diabetes, met-abolic syndrome and NASh. Ethnic disparities in central adiposity and visceral fat distribution have been hy-pothesized to contribute to these ethnic disparities. The current review focuses on the epidemiology of obesity and NASh among Asian populations.

Mild drinking habit is a risk factor for hepatocarcinogenesis in non-alcoholic fatty liver disease with advanced fibrosis

AIM The impact of mild drinking habit(less than 20 g/d of ethanol) on the clinical course of non-alcoholic fatty liver disease(NAFLD) has not been determined. We examined the influence of a mild drinking habit on liver carcinogenesis from NAFLD. METHODS A total of 301 patients who had been diagnosed as having NAFLD by liver biopsy between 2003 and 2016 [median age: 56 years, 45% male, 56% with nonalcoholic steatohepatitis, 26% with advanced fibrosis(F3-4)] were divided into the mild drinking group withe thanol consumption of less than 20 g/d(mild drinking group, n = 93) and the non-drinking group(n = 208). Clinicopathological features at the time of liver biopsy and factors related to hepatocellular carcinoma(HCC) occurrence were compared between the groups.RESULTS We observed significant differences in male prevalence(P = 0.01), platelet count(P = 0.04), and gammaglutamyl transpeptidase(P = 0.02) between the test groups. Over 6 years of observation, the HCC appearance rate was significantly higher in the mild drinking group(6.5% vs 1.4%, P = 0.02). Multivariate survival analysis using Cox's regression model revealed that hepatic advanced fibrosis(F3-4)(P < 0.01, risk ratio: 11.60), diabetes mellitus(P < 0.01, risk ratio: 89.50), and serum triglyceride(P = 0.04, risk ratio: 0.98) were factors significantly related to HCC in all NAFLD patients, while the effect of a drinking habit was marginal(P = 0.07, risk ratio: 4.43). In patients with advanced fibrosis(F3-4), however, a drinking habit(P = 0.04, risk ratio: 4.83), alpha-fetoprotein(P = 0.01, risk ratio: 1.23), and diabetes mellitus(P = 0.03, risk ratio: 12.00) were identified as significant contributors to HCC occurrence. CONCLUSION A mild drinking habit appears to be a risk factor for hepatocarcinogenesis in NAFLD patients, especially those with advanced fibrosis.

Significant cohort of non-alcoholic fatty liver disease with portal vein thrombosis in transplant waiting list

AIM: To characterize non-alcoholic fatty liver disease(NAFLD) presentation with esophageal varices. METHODS: We carried out a retrospective cohort study on 258 patients with esophageal varices at a single tertiary referral center. These patients underwent diagnosis of several liver diseases, including: NAFLDassociated cirrhosis, hepatitis B, hepatitis C, Wilson disease, autoimune liver diseases, and others. RESULTS: Of the 258 patients, 39% of patients exhibited esophageal varices due to NAFLD-associated cirrhosis. Of the 38(14.7%) patients developed hepatocellular carcinoma during follow-up, 52% were due to hepatitis B, 26% due to hepatitis C and 13.2% due to NAFLD. Of the 258 patients, 50.0% with NAFLD, 33.3% with hepatitis B, 26.3% with hepatitis C, and 58.3% with other diseases were alive at the end of the 5-year period with a significant difference according to the Kaplan-Meier log Rank test(P = 0.040). Portal vein thrombosis was detected in 47.5% of patients with NAFLD, in 29% of patients with hepatitis B, in 17% of patients with hepatitis C, and in 62% of patients with other related diseases(P < 0.0001). CONCLUSION: Our study showed a proportionally greater elevation in liver transplant candidacy in patients with NAFLD and portal vein thrombosis. Older patients were more prone to developing cirrhosis, hepatocellular carcinoma and a high mortality rate. However, younger patients exhibited more portal vein thrombosis and gastric varices.

Promoting genetics in non-alcoholic fatty liver disease: Combined risk score through polymorphisms and clinical variables

Non-alcoholic fatty liver disease(NAFLD) has a prevalence of approximately 30% in western countries, and is emerging as the first cause of liver cirrhosis and hepatocellular carcinoma(HCC). Therefore, risk stratification emerges as fundamental in order to optimize human and economic resources, and genetics displays intrinsic characteristics suitable to fulfill this task. According to the available data, heritability estimates for hepatic fat content range from 20% to 70%, and an almost 80% of shared heritability has been found between hepatic fat content and fibrosis. The rs738409 single nucleotide polymorphism(SNP) in patatin-like phospholipase domain-containing protein 3 gene and the rs58542926 SNP in transmembrane 6 superfamily member 2 gene have been robustly associated with NAFLD and with its progression, but promising results have been obtained with many other SNPs. Moreover, there has been proof of the additive role of the different SNPs in determining liver damage, and there have been preliminary experiences in which risk scores created through a few genetic variants, alone or in combination with clinical variables, were associated with a strongly potentiated risk of NAFLD, non-alcoholic steatohepatitis(NASH), NASH fibrosis or NAFLD-HCC. However, to date, clinical translation of genetics in the field of NAFLD has been poor or absent. Fortunately, the research we have done seems to have placed us on the right path: We should rely on longitudinal rather than on cross-sectional studies; we should focus on relevant outcomes rather than on simple liver fat accumulation; and we should put together the genetic and clinical information. The hope is that combined genetic/clinical scores, derived from longitudinal studies and built on a few strong genetic variants and relevant clinical variables, will reach a significant predictive power, such as to have clinical utility for risk stratification at the single patient level and even to esteem the impact of intervention on the risk of disease-related outcomes. Well-structured future studies would demonstrate if this vision can become a reality.

Hepatocellular carcinoma in non-alcoholic steatohepatitis:Current knowledge and implications for management

With the prevalence of hepatitis C virus expected to decline, the proportion of hepatocellular carcinoma(HCC) related to non-alcoholic steatohepatitis(NASH) is anticipated to increase exponentially due to the growing epidemic of obesity and diabetes. The annual incidence rate of developing HCC in patients with NASH-related cirrhosis is not clearly understood with rates ranging from 2.6%-12.8%. While multiple new mechanisms have been implicated in the development of HCC in NASH; further prospective long-term studies are needed to validate these findings. Recent evidence has shown a significant proportion of patients with non-alcoholic fatty liver disease and NASH progress to HCC in the absence of cirrhosis. Liver resection and transplantation represent curative therapeutic options in select NASHrelated HCC patients but have placed a significant burden to our healthcare resources and utilization. Currently NASH-related HCC is the fastest growing indication for liver transplant in HCC candidates. Increased efforts to implement effective screening and preventative strategies, particularly in non-cirrhotic NASH patients, are needed to reduce the future impact imposed by NASH-related HCC.

Hepatocellular carcinoma and non-alcoholic steatohepatitis:The state of play

Hepatocellular carcinoma(HCC) is now the fifth cancer of greatest frequency and the second leading cause of cancer related deaths worldwide. Chief amongst the risks of HCC are hepatitis B and C infection, aflatoxin B1 ingestion, alcoholism and obesity. The latter can promote non-alcoholic fatty liver disease(NAFLD), that can lead to the inflammatory form non-alcoholic steatohepatitis(NASH), and can in turn promote HCC. The mechanisms by which NASH promotes HCC are only beginning to be characterized. Here in this review, we give a summary of the recent findings that describe and associate NAFLD and NASH with the subsequent HCC progression. We will focus our discussion on clinical and genomic associations that describe new risks for NAFLD and NASH promoted HCC. In addition, we will consider novel murine models that clarify some of the mechanisms that drive NASH HCC formation.

Influence of Gut Microbiota and its Metabolites on Progression of Metabolic Associated Fatty Liver Disease

Metabolic associated fatty liver disease(MAFLD)has become a prevalent chronic liver disease worldwide because of lifestyle and dietary changes.Gut microbiota and its metabolites have been shown to play a critical role in the pathogenesis of MAFLD.Understanding of the function of gut microbiota and its metabolites in MAFLD may help to elucidate pathological mechanisms,identify diagnostic markers,and develop drugs or probiotics for the treatment of MAFLD.Here we review the pathogenesis of MAFLD by gut microbiota and its metabolites and discuss the feasibility of treating MAFLD from the perspective of gut microbes.

Gut microbiota contribution to hepatocellular carcinoma manifestation in non-alcoholic steatohepatitis

Recently,the gut microbiota has been recognized as an obvious active player in addition to liver steatosis/steatohepatitis in the pathophysiological mechanisms of the development of hepatocellular carcinoma(HCC),even in the absence of cirrhosis.Evidence from clinical and experimental studies shows the association of specific changes in the gut microbiome and the direct contribution to maintaining liver inflammation and/or cancerogenesis in nonalcoholic fatty liver disease-induced HCC.The composition of the gut microbiota differs significantly in obese and lean individuals,especially in the abundance of pro-inflammatory lipopolysaccharide-producing phyla,and,after establishing steatohepatitis,it undergoes minor changes during the progression of the disease toward advanced fibrosis.Experimental studies proved that the microbiota of obese subjects can induce steatohepatitis in normally fed mice.On the contrary,the transplantation of healthy microbiota to obese mice relieves steatosis.However,further studies are needed to confirm these findings and the mechanisms involved.In this review,we have evaluated well-documented clinical and experimental research on the role of the gut microbiota in the manifestation and promotion of HCC in nonalcoholic steatohepatitis(NASH).Furthermore,a literature review of microbiota alterations and consequences of dysbiosis for the promotion of NASH-induced HCC was performed,and the advantages and limitations of the microbiota as an early marker of the diagnosis of HCC were discussed.

Epidemiology,therapy and outcome of hepatocellular carcinoma between 2010 and 2019 in Piedmont,Italy

BACKGROUND Hepatocellular carcinoma(HCC)is the most common primary liver malignancy and the second leading cause of cancer deaths worldwide.It is often diagnosed at an advanced stage and therefore its prognosis remains poor with a low 5-year survival rate.HCC patients have increasingly complex and constantly changing characteristics,thus up-to-date and comprehensive data are fundamental.AIM To analyze the epidemiology and main clinical characteristics of HCC patients in a referral center hospital in the northwest of Italy between 2010 and 2019.METHODS In this retrospective study,we analyzed the clinical data of all consecutive patients with a new diagnosis of HCC recorded at"Santa Croce e Carle"Hospital in Cuneo(Italy)between 1 January 2010 and 31 December 2019.To highlight possible changes in HCC patterns over the 10-year period,we split the population into two 5-year groups,according to the diagnosis period(2010-2014 and 2015-2019).RESULTS Of the 328 HCC patients who were included(M/F 255/73;mean age 68.9±11.3 years),154 in the first period,and 174 in the second.Hepatitis C virus infection was the most common HCC risk factor(41%,135 patients).The alcoholic etiology rate was 18%,the hepatitis B virus infection etiology was 5%,and the non-viral/non-alcoholic etiology rate was 22%.The Child-Pugh score distribution of the patients was:class A 75%,class B 21%and class C 4%.The average Mayo end-stage liver disease score was 10.6±3.7.A total of 55 patients(17%)were affected by portal vein thrombosis and 158(48%)by portal hypertension.The average nodule size of the HCC was 4.6±3.1 cm.A total of 204 patients(63%)had more than one nodule<3,and 92%(305 patients)had a non-metastatic stage of the disease.The Barcelona Clinic Liver Cancer(BCLC)staging distribution of all patients was:4%very early,32%early,23%intermediate,34%advanced,and 7%terminal.Average survival rate was 1.6±0.3 years.Only 20%of the patients underwent treatment.Age,presence of ascites,BCLC stage and therapy were predictors of a better prognosis(P<0.01).A comparison of the two 5-year groups revealed a statistically significant difference only in global etiology(P<0.05)and alpha-fetoprotein(AFP)levels(P<0.01).CONCLUSION In this study analyzing patients with a new diagnosis of HCC between 2010-2019,hepatitis C virus infection was the most common etiology.Most patients presented with an advanced stage disease and a poor prognosis.When comparing the two 5-year groups,we observed a statistically significant difference only in global etiology(P<0.05)and AFP levels(P<0.01).

Disparate outcomes in Hispanic patients with metabolic dysfunctionassociated steatotic liver disease/steatohepatitis and type 2 diabetes: Large cohort study

BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)and metabolic dysfunction-associated steatohepatitis(MASH)are a growing health burden across a significant portion of the global patient population.However,these conditions seem to have disparate rates and outcomes between different ethnic populations.The combination of MASLD/MASH and type 2 diabetes increases the risk of hepatocellular carcinoma(HCC),and Hispanic patients experience the greatest burden,particularly those in South Texas.AIM To compare outcomes between Hispanic and non-Hispanic patients in the United States,while further focusing on the Hispanic population within Southeast Texas to determine whether the documented disparity in outcomes is a function of geographical circumstance or if there is a more widespread reason that all clinicians must account for in prognostic consideration.METHODS This cohort analysis was conducted with data obtained from TriNetX,LLC(“TriNetX”),a global federated health research network that provides access to deidentified medical records from healthcare organizations worldwide.Two cohort networks were used:University of Texas Medical Branch(UTMB)hospital and the United States national database collective to determine whether disparities were related to geographic regions,like Southeast Texas.RESULTS This study findings revealed Hispanics/Latinos have a statistically significant higher occurrence of HCC,type 2 diabetes mellitus,and liver fibrosis/cirrhosis in both the United States and the UTMB Hispanic/Latino groups.Allcause mortality in Hispanics/Latinos was lower within the United States group and not statistically elevated in the UTMB cohort.CONCLUSION This would appear to support that Hispanic patients in Southeast Texas are not uniquely affected compared to the national Hispanic population.

Pathological characterization of occult hepatitis B virus infection in hepatitis C virus-associated or non-alcoholic steatohepatitis-related hepatocellular carcinoma

Occult hepatitis B virus(HBV)infection,by definition,is a state in which infection with this virus does not manifest with the conventional diagnostic laboratory criteria reserved for the obvious form of HBV infection.As a result,occult HBV infection is commonly a surprise finding discovered accidently during the evaluation of other apparent liver diseases,such as hepatitis C virus(HCV)infection or non-alcoholic fatty liver disease and,more importantly,their evolution into life-threatening hepatocellular carcinoma.As infection with HCV and occult HBV is rarely considered when assessing these more obvious conditions,and in an attempt to offer a better understanding of this phenomenon,this study attempted to shed some light onto the uniqueness of occult HBV infection by addressing the natural history of HBV and HCV infections,as well as non-alcoholic fatty liver disease.This was carried out by taking into account the exclusive integration process undertaken by the HBV genome into infected host hepatocytes,with consideration given to conditions which afford reactivation of the occult infection and stress on the molecular mechanisms that underlie occult HBV infection.Finally,the clinical outcome of occult HBV infection and its relation to hepatocellular carcinoma is analyzed.

phosphatase and tensin homolog is a differential diagnostic marker between nonalcoholic and alcoholic fatty liver disease

AIM: To investigate the protein expression of phosphatase and tensin homolog (PTEN) in human liver biopsies of patients with alcoholic and non-alcoholic liver disease.METHODS: PTEN protein expression was assessed by immunohistochemistry in formalin-fixed, paraffin-embedded liver sections of patients with non-alcoholic fatty liver disease (NAFLD) (n = 44) or alcoholic liver disease (ALD) (n = 25). Liver resections obtained from 3 healthy subjects candidate for partial liver donation served as controls. Histological evaluations were performed by two experienced pathologists, and diagnoses established based on international criteria. The intensity of the PTEN staining in nuclei was compared between steatotic and non-steatotic areas of each liver fragment analyzed. For each liver specimen, the antibody-stained sections were examined and scored blindly by three independent observers, who were unaware of the patients&#x02019; clinical history.RESULTS: In healthy individuals, PTEN immunostaining was intense in both the cytoplasm and nuclei of all hepatocytes. However, PTEN was strongly downregulated in both the nucleus and the cytoplasm of hepatocytes from steatotic areas in patients with NAFLD, independently of the disease stage. In contrast, no changes in PTEN protein expression were observed in patients with ALD, regardless of the presence of steatosis or the stage of the disease. The degree of PTEN downregulation in hepatocytes of patients with NAFLD correlated with the percentage of steatosis (r = 0.3061, P = 0.0459) and the BMI (r = 0.4268, P = 0.0043). Hovewer, in patients with ALD, PTEN expression was not correlated with the percentage of steatosis with or without obesity as a confounding factor (P = 0.5574). Finally, PTEN expression level in steatotic areas of ALD patients was significantly different from that seen in steatotic areas of NAFLD patients (P &#x0003c; 0.0001).CONCLUSION: PTEN protein expression is downregulated early in NAFLD, but not in ALD. PTEN immunohistochemical detection could help in the differential diagnosis of NAFLD and ALD.