Hepatocellular carcinoma, alcohol, and cirrhosis: facts and hypotheses

A prospective study of 68Ga-PSMA PET/CT imaging of HCC as diagnosed on conventional imaging to evaluate for potential 177Lu-PSMA therapy

OBJECTIVE

PSMA expression is seen in many solid tumours in addition to prostate cancer and several studies and case reports have shown PSMA expression and 68Ga-PSMA imaging of hepatocellular carcinoma (HCC). Our prospective study evaluates the role of 68Ga-PSMA in HCC patients and compares it to conventional imaging (CE-CT/MRI).

METHODS

Patients with radiologically and/or histopathologically confirmed HCC were included and all had undergone serum alpha-fetoprotein (S.AFP) assessment as well as CE-CT/MRI prior to PSMA PET/CT. Acquired whole-body PET/CTs were analysed both visually and quantitatively by two experienced nuclear medicine physicians.

RESULTS

Forty-one (41) patients (36 male; 5 female) with known HCC and a mean age of 53.9 ± 10.9 years underwent 68Ga-PSMA PET/CT. All patients had lesions on conventional imaging but only 38/41 patients showed 68Ga-PSMA uptake. Conventional imaging revealed 18 patients with single lesions, all of which were tracer avid. Twenty-three (23) of 41 patients had multifocal (> 2) hepatic lesions on CE-CT/MRI of which 3 patients showed no 68Ga-PSMA uptake, 7 showed tracer uptake in a single lesion only and 13 patients had multifocal tracer avid lesions. There was no correlation observed between S. AFP level and tumour SUVmax on 68Ga-PSMA PET/CT.

CONCLUSION

68Ga-PSMA PET/CT imaging of HCC may complement conventional imaging and identify patients for potential theranostic intervention.

Epidemiology of primary and secondary liver cancers

Primary liver cancer is the sixth most common cancer worldwide with a wide geographic distribution. The incidence of primary liver cancer is increasing and there is still a higher prevalence in developing countries. Early recognition remains an obstacle and lack of it results in poor outcomes for hepatocellular carcinoma (HCC), the most prevalent primary liver cancer, and cholangiocarcinoma. The most common risk factors associated with HCC are hepatitis B and chronic hepatitis C infections, alcohol use, smoking, and aflatoxin exposure. Emerging risk factors such as obesity might play an important role in the future because of the increasing prevalence of this condition.

Tissue homeostasis and cancer

Epithelial cells are known to release an important amount of cytokines capable to modulate immune system functions. On the other hand, immune system cells can release cytokines, which play an important role in the control of the growth of epithelial cells. In this paper, we stand the hypothesis that a mutual (reciprocal) growth regulation exists between epithelial cells and immune system. We propose a model describing plausible cytokine circuits that may regulate (inhibit) both epithelial growth and epithelial inflammation. In addition, we describe how dysfunction of these circuits could lead to tumoral growth, excessive inflammation or both. A failure in the regulation of epithelial growth by the immune system could give rise to a neoplasm, and a failure in the regulation of the immune system by the epithelium could give rise to inflammatory or autoimmune diseases. This model may satisfactorily explain the link between inflammation and cancer.

Epidemiology and carcinogenesis of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) shows marked variation worldwide but the magnitude of this tumor is reflected by the occurrence of at least 1 million new cases annually and the uniformly dismal outlook with median survivals of <25 months after resection and <6 months with symptomatic treatment. The strikingly uneven distribution of this tumor parallels the prevalence of hepatitis B infection with rising incidence in western countries attributed to hepatitis C infection. Chronic hepatitis and cirrhosis constitute the major preneoplastic conditions in the majority of HCCs and may be related to other etiologic agents such as environmental chemical carcinogens including nitrites, hydrocarbons, solvents, organochlorine pesticides, and the chemicals in processed foods, cleaning agents, cosmetics and pharmaceuticals, as well as plant toxins such as anatoxins produced by fungi that cause spoilage of grain and food in the tropics. Genetic diseases such as genetic hematochromatosis, Wilson's disease, alpha-1-antitrypsin deficiency, and the inborn errors of metabolism including hereditary tyrosinemia and hepatic porphyria, are known to be associated with HCC. Numerous genetic alterations and the modulation of DNA methylation are recognized in HCC and it is likely that these genetic and epigenetic changes combine with factors involved in chronic hepatocyte destruction and regeneration to result in neoplastic growth and multiple molecular pathways may be involved in the production of subsets of hepatocellular tumors.

Hepatocellular carcinoma: an overview

Hepatocellular carcinoma remains widely prevalent in tropical Africa and south-east Asia and is largely related to chronic hepatitis B virus (HBV) infection. Primary prevention by vaccination of infants at or near birth is effective but any reduction in tumour incidence cannot be expected for decades to come yet, even in those countries in which the necessary resources exist, as millions of adults remain chronically infected. Meanwhile, the incidence is rising in Japan, Mediterranean countries of Europe, Middle East and North Africa and in the USA, largely due to chronic hepatitis C virus (HCV) infection introduced by the indiscriminate use of unscreened blood and blood products in the recent past. Much has been learned from molecular biological studies on hepatocarcinogenesis incriminating the HBX gene of HBV, the core protein of HCV and a unique guanine to thymine transversion at codon 249 has been observed in cases due to aflatoxin exposure. The subject of precancerous lesions, notably adenomatous/dysplastic nodules and large-cell/small-cell change continues to be a source of much debate and the distinction of nodular lesions in cirrhosis from early carcinoma remains uncertain. Spontaneous regression of hepatocellular carcinoma is rare but it is probably immunologically mediated and treatment by activated T-lymphocytes may reduce recurrence rates after surgery. The positive identification of hepatocellular carcinoma by a liver-specific antibody has greatly facilitated the diagnosis in difficult cases.

Hepatocellular carcinoma in primary biliary cirrhosis: similar incidence to that in hepatitis C virus-related cirrhosis

OBJECTIVES

The prevalence of hepatocellular carcinoma (HCC) in primary biliary cirrhosis (PBC) is not well established, as some reports suggest a low risk, whereas others indicate that HCC may be no less frequent than in other types of cirrhosis.

METHODS

We compared the incidence of HCC in a series of 140 patients with PBC (five men, 135 women, mean age 54 +/- 1.6 yr) followed-up for a mean of period of 5.6 +/- 0.4 yr with a group of patients with cirrhosis related to hepatitis C virus (HCV) who were matched for age, sex, and follow-up period. In all patients, HCC was prospectively screened by clinical, laboratory, and ultrasound procedures.

RESULTS

Five patients with PBC (3.6%) developed HCC. All were in stage IV of the disease. The incidence of HCC in the 45 patients with late stages of the disease (III or IV) was 11.1%, similar to that found in patients with HCV-related cirrhosis, which was 15.0%. The relative risk for HCC in late stages of PBC was of 0.812 (95% CI, 0.229-2.883) with respect to HCV-related cirrhosis. The probability for developing HCC was significantly higher in patients with HCV-related cirrhosis than in PBC patients overall (p = 0.001), but was similar in patients with HCV-related cirrhosis and in patients with PBC in stages III and IV (p = ns).

CONCLUSION

The risk for HCC in patients with late stages of PBC is similar to that in patients with HCV-related cirrhosis.

Lipopolysaccharide tolerance and ethanol modulate hepatic nitric oxide production in a gender-dependent manner

This study was directed at the role of tolerance to endotoxin (lipopolysaccharide, LPS) and ethanol (EtOH) intoxication in modulating hepatic nitric oxide (NO) production, and the demonstration of gender differences. Previous studies demonstrated that tolerance to either LPS or EtOH was associated with reduced hepatic production of superoxide anions. We now tested the hypothesis that the reduced hepatic production of superoxide anions during tolerance to LPS and the altered response to EtOH are accompanied by increased sensitivity of hepatic NO release to stimulation. Age-matched male and female Sprague-Dawley rats were made tolerant to LPS by an i.v. injection of LPS (0.5 or 0.45 mg/kg) 2 days prior to an in vivo EtOH infusion for 3 h (LPS-EtOH group). Control groups were saline-pretreated, saline-infused; saline-pretreated, EtOH-infused; and LPS-pretreated, saline-infused. At the end of the infusion, isolated hepatocytes, Kupffer, and sinusoidal endothelial cells were cultured for 20 h for subsequent measurement of basal (spontaneous) and in vitro-stimulated nitrite release. LPS-tolerance resulted in significantly enhanced stimulated NO production by hepatocytes and Kupffer cells in both male and female rats. EtOH abolished this priming effect in hepatocytes from male, but not from female rats. The priming effect was markedly diminished by EtOH in Kupffer cells of female rats only. LPS-tolerance increased NO production by stimulated endothelial cells of males, and decreased NO production by cells of females. EtOH infusion did not influence NO production by endothelial cells from male rats and it reversed the LPS-tolerance-induced inhibition in females. These data demonstrate that modulation by LPS-tolerance of hepatic NO release in EtOH-treated rats leads to enhanced stimulated NO production, while hepatic superoxide anion release was previously shown to be reduced within the same time frame. Since NO is able to scavenge superoxide, the LPS-tolerance-induced alterations in the EtOH effects on NO production may have a potential significance in modulating - in a time-dependent manner - oxidative injury associated with LPS and acute EtOH intake.

Hepatocellular carcinoma without cirrhosis in the West: epidemiological factors and histopathology of the non-tumorous liver. Groupe d'Etude et de Traitement du Carcinome Hépatocellulaire

BACKGROUND/AIM

In the West, hepatocellular carcinoma rarely occurs in patients without cirrhosis. In these patients, epidemiological factors and the histopathology of the non-neoplastic liver are not well known. The aim of this study was to clarify these points.

METHODS

We studied 30 patients (26 men, 28-87 years) with hepatocellular carcinoma and histologically-proven non-cirrhotic livers. Serological markers of HBV and HCV infection, as well as alcohol and tobacco consumption were evaluated. Pathological changes in the non-tumorous liver (fibrosis, inflammation, steatosis, alcoholic hepatitis lesions, iron overload, and large cell dysplasia) were systematically assessed using semi-quantitative scores.

RESULTS

Twenty patients had alcohol intake > or =30 g/d and 16 were smokers. Serological HBV or HCV markers were positive in 10 patients. Only four patients had no exposure to alcohol or tobacco and no serological markers of HBV or HCV Histological examination showed that all livers had pathological changes. Seventeen patients (57%) had clearly-identified chronic liver disease: chronic hepatitis (n = 10) or alcoholic liver disease (n = 7). Non-specific and moderate pathological changes were observed in the 13 other patients (43%), with different degrees of fibrosis, activity, steatosis, and iron overload. Large cell dysplasia was present in 12 patients (40%).

CONCLUSIONS

In our study, all patients with hepatocellular carcinoma and non-cirrhotic livers had non-tumorous pathological liver changes, especially iron overload and large cell dysplasia. These results suggest that hepatocellular carcinoma originates from an abnormal histological background, even in non-cirrhotic liver.

Enhanced Gi-protein-mediated mitogenesis following chronic ethanol exposure in a rat model of experimental hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is associated with increased expression and function of inhibitory guanine nucleotide regulatory proteins (Gi-proteins). This study addresses the effects of chronic ethanol exposure on the expression and function of adenylyl cyclase (AC)-linked G-proteins (Gs and Gi) and growth in experimental HCC. G-protein expression and function was determined by immunoblot in the hepatic tumorigenic H4IIE cell line and isolated cultured hepatocytes in the absence or presence of ethanol (5-100 mmol/L). Chronic exposure (24 hours) to ethanol dose-dependently increased Gialpha1/2 expression in the H4IIE cell line, but not in cultured hepatocytes. Gsalpha-protein expression remained unchanged in both H4IIE cells and cultured hepatocytes following ethanol treatment. In addition, ethanol directly activated a Gi-protein, because pertussis toxin (PTx)-catalyzed, adenosine diphosphate (ADP)-dependent ribosylation of Gialpha substrates decreased following ethanol treatment. The increased functional activity of Gialpha1/2-protein expression was confirmed by demonstrating that ethanol dose-dependently inhibited basal and stimulated AC activity in H4IIE cells, while not significantly altering basal AC activity in isolated cultured hepatocytes. Furthermore, while ethanol had no significant effect on basal mitogenesis in H4IIE cells or hepatocytes, increased mitogenesis caused by direct Gialpha-protein stimulation (mastoparan M7; 10-5,000 nmol/L) was further enhanced in the presence of ethanol, an effect that was completely blocked following Gi-protein inhibition (PTx; 100 ng/mL). In contrast, activation of Gi-proteins using M7 failed to alter cellular mitogenesis in isolated cultured hepatocytes, whether in the absence or presence of ethanol. Finally, analysis of mitogen-activated protein kinase (MAPK) activity demonstrated that chronic ethanol treatment further enhanced Gi-protein-stimulated MAPK activity in hepatic tumorigenic cells. In conclusion, these data demonstrate that ethanol enhances cellular mitogenesis in experimental HCC as a result of, at least in part, a Gi-MAPK-dependent pathway. Furthermore, this effect may be caused by ethanol's direct up-regulation of the expression and activity of Gi-proteins in HCC.

Primary and metastatic liver cancer

OBJECTIVES

To review liver physiology, the disease process, diagnostic tests, and current treatment options for primary and metastatic liver cancer.

DATA SOURCES

Research studies, review articles, and textbooks relating to liver cancer.

CONCLUSIONS

Surgical resection offers the best available treatment modality, but only a small percentage of patients are eligible. However, combined treatment of radiation therapy and chemotherapy (systemic and intra-arterial), as well as chemoembolization, cryosurgery, and transplantation, offers hope of palliation, conversion of unresectable to resectable disease, and prolonged survival.

IMPLICATIONS FOR NURSING PRACTICE

Understanding and knowledge of the disease process and treatment modalities for primary and metastatic liver cancer will assist the oncology nurse in educating patients and families during their diagnostic and treatment phases.

Premalignant lesions and hepatocellular carcinoma in a non-cirrhotic alcoholic patient with iron overload and normal transferrin saturation

A 66-year-old white man had a hepatic resection for a 6-cm well-differentiated hepatocellular carcinoma which had developed in a non-cirrhotic liver. The only risk factors found were heavy drinking, smoking and heterozygosity for the C282Y mutation of the HFE gene. The liver was mildly fibrotic and overloaded with iron. It also contained numerous iron-free hepatocellular lesions from <1 to 10 mm, suggesting a premalignant change. These lesions were of three types: (i) iron-free foci, (ii) hyperplastic nodules and (iii) dysplastic nodules with severe dysplasia or even foci of well-differentiated grade I hepatocellular carcinoma. This observation suggests the possibility of malignant transformation of the liver in the newly-described syndrome of iron overload and normal transferrin saturation. It also illustrates the multistep process of carcinogenesis in the non-cirrhotic liver.

The role of Src kinase in the potentiation by ethanol of cytokine- and endotoxin-mediated nitric oxide synthase expression in rat hepatocytes

This study demonstrates that exposure of primary rat hepatocytes or mouse BNL Cl.2 liver cell line to ethanol causes potentiation of tumor necrosis factor-alpha (TNF-alpha)- and lipopolysaccharide (LPS)-stimulated nitrite accumulation. The potentiating effect of ethanol (0.02-2 mM) appears to be time and concentration dependent. Consistent with nitrite production, the amount of inducible nitric oxide synthase (iNOS) mRNA and protein is initially detected at 4 hr after treatment with TNF-alpha/LPS/ethanol. Furthermore, the capability of these agents to induce iNOS expression is primarily determined by the age of the animals. Interestingly, antioxidants such as N-acetylcysteine (NAC), ascorbic acid, or alpha-tocopherol fail to inhibit TNF-alpha/LPS/ethanol-induced increase in iNOS protein. In addition, several kinase inhibitors, including staurosporine, genistein, curcumin, and herbimycin A, were used to examine their effects on this induction. Among them, only herbimycin A potently inhibits the accumulation of nitrite and iNOS expression. In vitro kinase assay verifies that Src tyrosine kinase is rapidly activated with a peak at 1 hr after treatment with TNF-alpha/LPS/ethanol but is not activated by these agents singly or doubly. As expected, herbimycin A can block Src kinase activity under circumstances in which iNOS expression is also inhibited. However, our results do not indicate that the mitogen-activated protein kinase is activated after treatment with these agents. The study results suggest that Src tyrosine kinase plays a prominent role in transducing the signal to induce iNOS expression in hepatocytes treated with TNF-alpha/LPS/ethanol.

Etiology, screening, and treatment of hepatocellular carcinoma

The prognosis with large hepatocellular carcinomas is poor, and only palliative treatment is available. Small tumors are amenable to several modes of treatment, including liver transplantation, resection, or alcohol injection, with acceptable 5-year survival rates. Although the value of screening for hepatocellular carcinoma has yet to be shown, these data, coupled with the recognition of at-risk groups and useful diagnostic techniques, might encourage the clinician to screen at-risk patients in the clinic. New imaging techniques such as ultrasonographic angiography enhanced with CO2 microbubbles, or color Doppler ultrasound, may clarify the intratumoral blood flow of small tumors.

Alcohol-related cancer risk: a toxicokinetic hypothesis

Consumption of alcoholic beverages is an accepted social custom world-wide. This makes its involvement in events contributing to human cancer risk very important. Although it is neither tumorigenic nor genotoxic in animals, ethanol can potentiate the carcinogenic risk associated with certain environmentally present agents. The reasons for such a synergistic action are speculative, but among theories postulated may be ethanol's ability to modify the toxicokinetics/dynamics of carcinogen metabolism. Experiments conducted with rodents and primates support this hypothesis, demonstrating increased exposure of posthepatic organs to nitrosamines when given in combination with ethanol, followed by enhancement of DNA adduct formation and, at least in rodents, of tumor development. In addition, ethanol may induce enzymes responsible for carcinogen activation, including hepatic cytochrome P450 2E1 in rodents and humans, and in lung, kidney, and brain in rodents. Studies have also shown that these effects can extend to the next generation via maternal and in utero fetal exposure. What impact such ethanol-induced modulations have on tumorigenesis during childhood and later stages of life needs to be investigated further.

A strong negative association between alcohol consumption and the risk of hepatocellular carcinoma in cirrhotic patients. A case-control study

We carried out a hospital-based, case-control study to assess the association of both the Hepatitis B Virus (HBV) infection and the lifetime daily alcohol intake with the risk of developing hepatocellular carcinoma (HCC) in patients with liver cirrhosis (LC). Cases were 62 consecutive inpatients of a Gastroenterology Division in whom a first diagnosis of HCC superimposed on LC was made. Two control groups were used: 310 patients without liver disease, matched 1:5 with cases and randomly selected from inpatients of the same hospital, and 97 consecutive asymptomatic inpatients in whom the first diagnosis of LC was made. Alcohol intake was quantified in all subjects by a standardized questionnaire. HBV infection was associated with HCC development in cirrhotics (odds ratio = 6.8; 95% confidence interval = 1.4-32.3), whereas we observed a trend towards a decreased HCC risk at increased alcohol intake values (odds ratio from 1 for lifetime abstainers to 0.2 for drinkers of 175 g/day or more). Our results suggest that alcohol intake is not a direct determinant of HCC, but its role is mediated by LC. Cirrhotics with high alcohol intake do not usually survive long enough to develop HCC.

Epidemiology of alcoholic liver disease

Although mortality from alcoholic liver disease has declined in some Western countries in recent years, elsewhere it is increasing and overall it remains a major health problem. Deaths are predominantly seen in patients with alcoholic hepatitis or cirrhosis, and when they occur in patients with fatty liver are usually unrelated to liver disease. Progression to cirrhosis is correlated with the severity of fatty liver and particularly with the presence of alcoholic hepatitis. Mortality from cirrhosis is strongly correlated with per capita alcohol consumption. The decline in cirrhosis mortality rates seen recently is related in part to decreases in per capita consumption, but probably also to the growth of self-help organizations which facilitate abstinence from alcohol. Recent studies suggest there is not an invariable dose-response relationship between alcohol intake and the severity of liver disease and that alcohol has a permissive effect which allows other aetiological factors to operate. Factors that influence susceptibility to alcoholic liver disease include gender (women develop alcoholic cirrhosis more readily than men), concomitant hepatitis C infection and possibly hepatitis B infection. It is uncertain whether HLA status or immune mechanisms are implicated. The systematic use of screening tests for hazardous consumption combined with early intervention therapies offers a good prospect of reducing morbidity and mortality from alcoholic liver disease.