Conditions associated with hepatocellular carcinoma

Hepatocellular carcinoma: predisposing conditions and precursor lesions

The global incidence of HCC is rising; in the United States, its rise is in parallel to that of cirrhosis due to the HCV and obesity epidemics. The lack of adequate treatment for advanced HCC mandates both prevention and early detection of these lesions. The limitations of currently available histopathologic evaluations, serologic markers, and radiographic imaging modalities in detecting HCC and its precursors have been outlined in this review. Refinements of all of these may lead to better HCC detection, earlier intervention, and successful treatment. Randomized controlled trials are necessary to evaluate the most efficacious and cost-effective approach to screening.

Liver cancer

The prognosis of patients with HCC remains dismal. Even in the subgroups of patients who have the most favorable characteristics and are eligible for surgical resection, the 5-year survival rate is less than 25%. For patients with more advanced disease, the median survival time is less than 1 year. The good news in HCC research is that the disease can be prevented. In Taiwan, the rate of HCC in children aged 6 to 9 years decreased from 5.2 per million population before the neonatal vaccination program began in 1984 to 1.3 per million population in the first vaccinated cohort. Treatment of viral hepatitis with IFN may decrease the rates of long-term development of HCC. Other agents that may prevent second primary tumors following resection of HCC, such as polyprenoic acid and acylic retinoid, are also being investigated.

Nonsurgical treatment of hepatocellular carcinoma

Given the poor prognosis of HCC and the therapeutic challenge posed by underlying liver cirrhosis, efforts and resources must be directed towards preventive strategies. Return on the investment in such research is likely to be greater than can be expected from treatment of advanced disease.

Short- and intermediate-term carcinogenicity testing--a review. Part 1: the prototypes mouse skin tumour assay and rat liver focus assay

Carcinogenicity testing is by far the most expensive and time-consuming study type of toxicology. For many years, the lifetime exposure with the maximum tolerated dose in two rodent species has been the gold standard of carcinogenicity testing of pharmaceuticals. Major change was introduced by the Fourth International Conference on Harmonization in July 1997; a chronic rodent bioassay in one species and a short-term carcinogenicity assay are regarded as sufficient for registration. Such requirements provide the opportunity to redirect the vast resources previously spent on the lifetime study in the second species. Numerous experimental protocols for short- and intermediate-term carcinogenicity testing in many target tissues have been available for years. The first part of this review describes the basic principles of short- and intermediate-term carcinogenicity testing using the examples of the widely used mouse skin tumour assay and the rat liver foci assay. In the context of these experimental models, the discrimination and quantification of initiating and promoting activity and the use of preneoplastic lesions as endpoints in carcinogenicity testing are described. The review includes the limitations of the models with regard to the extrapolation from effects observed in animal experiments to a potential exposure of humans.

Disease progression and hepatocellular carcinogenesis in patients with chronic viral hepatitis: a prospective observation of 2215 patients

BACKGROUND/AIMS/METHODS

The aim of this study was to elucidate the rate of development to cirrhosis and the rate of appearance of hepatocellular carcinoma in chronic viral hepatitis and to assess the risk factors for the development of disease in 2215 consecutive patients with viral hepatitis who were prospectively studied for a median observation period of 4.1 years.

RESULTS

The rates of development to cirrhosis were 7.6%, 21.7%, and 32.2%, at the 5th, 10th, and 15th year, respectively. The carcinogenesis rates were 3.4%, 10.5%, and 22.4% at the 5th, 10th, and 15th year, respectively. The appearance rates of cancer in 645 patients with only hepatitis B surface antigen and in 1500 patients with only anti-hepatitis C virus antibodies were 2.1% and 4.8% at the 5th year, 4.9% and 13.6% at the 10th year, and 18.8% and 26.0% at the 15th year, respectively. The proportional hazard model identified that the amount of alcohol intake (p= 0.0002) and the indocyanine green retention rate (p= 0.022) were independently associated with carcinogenesis in hepatitis type B; and stage of hepatitis (p<0.0001), gamma-glutamyl transpeptidase (p= 0.0046), history of blood transfusion (p=0.0093), albumin (p=0.012), and amount of alcohol intake (p= 0.031) were independently associated with the carcinogenesis rate in hepatitis type C. Although the severity of portal fibrosis was closely correlated with the future disease development and carcinogenesis in chronic hepatitis C, it was not a good predictor in chronic hepatitis B.

CONCLUSION

These epidemiological results suggest that there are some differences in the activity and modes of disease progression and cancer promotion between hepatitis B virus infection and hepatitis C virus infection.

Liver, gallbladder, extrahepatic bile ducts, and pancreas

BACKGROUND

The liver, gallbladder, bile ducts, and pancreas have a common embryologic origin; cancers that arise from these sites therefore are expected to share a similar spectrum of histologic types. These cancers are known for their extremely poor prognoses.

METHODS

Data from the Surveillance, Epidemiology, and End Results Program regarding the incidence, distribution of histologic types, stage of disease, and survival for cancers of the gallbladder (n = 4412), extrahepatic bile ducts (n = 3486), pancreas (n = 23,116), and liver (n = 6,391) were reviewed. The most common histologic types are discussed, and the frequency of rare types is reported.

RESULTS

The incidence of biliary cancer decreased, while the incidence of hepatic and pancreatic cancer rose slightly over the 15-year period from 1973 to 1987. Age and sex distributions varied by histologic type. Greater than 98% of pancreatic and biliary cancers were carcinomas, and adenocarcinoma (not otherwise specified) was the most common histologic type recorded. In the liver, hepatocellular carcinoma was the most common type, followed by intrahepatic cholangiocarcinoma. The overall 5-year relative survival rates for these cancers were very low: gallbladder, 12.3%; extrahepatic bile duct, 12.7%; liver 3.1%; and pancreas 2.5% (all stages combined, 1978-1986).

CONCLUSIONS

This review confirmed that these carcinomas are associated with a very poor outcome; however, survival was influenced by stage of disease and histologic type. In the gallbladder and extrahepatic bile ducts, papillary adenocarcinoma was associated with the best outcome of all histologic types, and in the exocrine pancreas, mucinous cystadenocarcinoma was associated with the best prognosis.

A multivariate analysis of risk factors for hepatocellular carcinogenesis: a prospective observation of 795 patients with viral and alcoholic cirrhosis

To elucidate the appearance rates of hepatocellular carcinoma in cirrhosis and to assess the risk factors for hepatocellular carcinogenesis, we prospectively studied 795 consecutive patients with viral or alcoholic cirrhosis for 2 to 17 yr (median of 5.8 yr). During the observation period, hepatocellular carcinoma developed in 221 patients. Cumulative appearance rates of hepatocellular carcinoma were 19.4%, 44.3% and 58.2% at the end of the fifth, tenth and fifteenth years, respectively. When classified by the type of hepatitis virus infection, the appearance rates of hepatocellular carcinoma in 180 patients with only HBsAg and in 349 patients with only antibodies to hepatitis C virus were 14.2% and 21.5% at the fifth yr, 27.2% and 53.2% at the tenth yr and 27.2% and 75.2% at the fifteenth yr, respectively. Cox proportional hazard model identified that alpha-fetoprotein levels (p = 0.00001), age (p = 0.00067), positive hepatitis C virus antibodies (p = 0.00135), total alcohol intake (p = 0.00455) and indocyanine green retention rate (p = 0.04491) were independently associated with the appearance rates of hepatocellular carcinoma. Whereas age and indocyanine green retention rate were independent predictors for the appearance rate of liver tumor in the subgroup of HBsAg-positive patients, alpha-fetoprotein levels, age and past alcohol consumption were independent predictors in the group of hepatitis C virus antibody-positive patients. These epidemiological results suggest that some differences exist in the activity and modes of cancer promotion between hepatitis B virus infection and hepatitis C virus infection.

Expression of androgen receptor mRNA in human hepatocellular carcinomas and hepatoma cell lines

The expression of androgen receptor messenger RNA in hepatocellular carcinomas and hepatoma cell lines was studied using Northern-blot analysis and the complementary DNA-polymerase chain reaction method. Androgen receptor messenger RNAs were detected (although in low levels) in both hepatocellular carcinoma tissues and noncancerous tissues of the liver in all eight cases we studied, except for the tumor sample of one case. None of the hepatoma cell lines studied, however, expressed detectable levels of androgen receptor messenger RNA except for the SK-HEP-1 hepatoma cell line.