Childhood primary hepatocellular carcinoma and hepatitis B virus infection

Pharmacotherapy options for managing hepatitis B in children

INTRODUCTION

To eliminate viral hepatitis by 2030, the World Health Organization (WHO) launched the first global health sector strategy on viral hepatitis, with particular focus given to hepatitis B and C in 2016. To achieve the reduction of mortality in children, it is indispensable to know which children should be treated and how to treat them.

AREA COVERED

In this article, the authors review the antiviral treatment of children with chronic hepatitis B virus (HBV) infection including antivirals available for children with chronic HBV infection.

EXPERT OPINION

The approvals of nucleos(t)ide analogues (NAs) and pegylated interferon (PEG-IFN) for children have lowered a hurdle to the initiation of antiviral treatment in children. The international guidelines use nearly the same criteria of antiviral treatment for children with chronic HBV infection, but the WHO guidelines provide a cautious stance on the antiviral treatment of children. Not only PEG-IFN but also NAs with a high genetic barrier to drug resistance should be the first-line treatment for children. In settings with limited medical resources, NAs can be the first-line treatment for children. Although the concept of an 'immune-tolerant phase' is challenged, evidence is not sufficient to recommend the treatment of HBeAg-positive immune-tolerant children.

Characteristics of Hepatitis B Virus-associated Hepatocellular Carcinoma in Children: A Multi-center Study

INTRODUCTION

Pediatricians and liver specialists in the United States and Canada continue to encounter hepatitis B virus (HBV) infection in high-risk populations, including unvaccinated children, adopted children, and immigrants. Although hepatocellular carcinoma (HCC) is a known complication of HBV, there exists a paucity of data regarding the clinical presentation of HBV-associated HCC in children in these countries.

METHODS

Investigators at 4 medical centers with large numbers of HBV-positive children queried their pathology and/or oncology databases to identify all cases of HBV-infected children <18 years old presenting with HCC between 1990 and 2015. Clinical data were extracted from chart review.

RESULTS

The group identified 8 patients, 8 to 17 years old, including 6 (75%) males. All individuals were assumed to be infected through vertical transmission. Three (38%) presented initially to the emergency room, 2 (25%) to a general pediatrician, 1 (13%) to a hepatologist, and the initial location was not documented in 2 (25%) cases. Three patients were asymptomatic, but the most common symptoms were abdominal pain (50%) and fatigue (38%). Hepatomegaly was present in 5 (63%) patients. Viral load was not documented in any patient. Only 3 patients had their HBeAg status documented and all individuals were HBeAg(-) and anti-HBe(+). Aspartate aminotransferase (AST) ranged from 13 to 575 IU/L, and alanine aminotransferase (ALT) ranged from 14 to 212 IU/L; 4 patients had AST and ALT < 1.5 times the upper limit of normal. Three patients had elevated bilirubin and gamma glutamyl transpeptidase (GGT), and 3 had normal bilirubin and GGT; 1 patient had unknown bilirubin and a separate patient had unknown GGT. Alpha-fetoprotein (AFP) was elevated in 3 patients (range 2.556-7.600 ng/mL), normal in 2 patients, and not documented in 3 patients. Ultrasound was initially used to identify the tumor in 5 patients whereas computerized axial tomography scan was used in 3 patients. Six patients had multiple nodules on initial imaging.

CONCLUSIONS

Although rare, HBV-associated HCC occurs in young children, often with normal liver enzymes, bilirubin, GGT, and AFP. Only routine imaging with ultrasound or computerized axial tomography scan consistently identified the tumor. These data may help inform screening for HCC including age of initiation and the role for imaging over laboratory testing.

Antiviral therapy in management of chronic hepatitis B viral infection in children: A systematic review and meta-analysis

Most individuals with chronic hepatitis B viral (HBV) infection acquired the infection around the time of birth or during early childhood. We aimed to synthesize evidence regarding the effectiveness of antiviral therapy in the management of chronic HBV infection in children. We conducted a comprehensive search of multiple databases from 1988 to December 2, 2014, for studies that enrolled children (<18 years) with chronic HBV infection treated with antiviral therapy. We included observational studies and randomized controlled trials (RCTs). Two independent reviewers selected studies and extracted data. In the 14 included studies, two cohort studies showed no significant reduction in the already low risk of hepatocellular carcinoma or cirrhosis and 12 RCTs reported intermediate outcomes. In RCTs with posttreatment follow-up <12 months, antiviral therapy compared to placebo improved alanine aminotransferase normalization (risk ratio [RR] = 2.3, 95% confidence interval [CI] 1.7-3.2), hepatitis B e antigen (HBeAg) clearance/loss (RR = 2.1, 95% CI 1.5-3.1), HBV DNA suppression (RR = 2.9, 95% CI 1.8-4.6), HBeAg seroconversion (RR = 2.1, 95% CI 1.4-3.3), and hepatitis B surface antigen clearance (RR = 5.8, 95% CI 1.1-31.5). In RCTs with posttreatment follow-up ≥12 months, antiviral therapy improved cumulative HBeAg clearance/loss (RR = 1.9, 95% CI 1.7-3.1), HBeAg seroconversion (RR = 2.1, 95% CI 1.3-3.5), alanine aminotransferase normalization (RR = 1.4, 95% CI 1.1-1.7), and HBV DNA suppression (RR = 1.4, 95% CI 1.1-1.8) but not hepatitis B surface antigen clearance or seroconversion.

CONCLUSION

In children with chronic HBV infection, antivirals compared to no antiviral therapy improve HBV DNA suppression and frequency of alanine aminotransferase normalization and HBeAg seroconversion.

Hepatitis B virus infection in children

For two decades, hepatitis B vaccine has been integrated into national routine childhood vaccination programs in almost all countries. The prevalence of HBsAg has decreased in children worldwide. However, there are children who miss the benefit of hepatitis B vaccine in some regions and countries. Long-term follow-up studies have revealed the clinical outcomes of chronic hepatitis B virus infection in children. A small percentage of chronically infected children develop liver cirrhosis and hepatocellular carcinoma. However, it is controversial who should be treated and when antiviral treatment should be initiated in children. Compared with adult studies, the data are insufficient to evaluate the pathogenesis of hepatitis B infection and the efficacy of antiviral treatment in childhood. New antiviral drugs have been approved for children and adults. Also, oral antiviral drugs are administered to pregnant women to reduce the hepatitis B virus mother-to-child transmission rate.

Childhood hepatocellular carcinoma: a clinicopathological study of 12 cases with special reference to EpCAM

AIMS

To elucidate the characteristics of hepatocellular carcinoma (HCC) in children.

METHODS AND RESULTS

A retrospective search of our database identified 12 children with HCC (aged 10 months to 11 years; male/female ratio of 5:7). Their pathological features were compared with those of adult HCCs (n = 20), fibrolamellar HCCs (n = 14), and hepatoblastomas (n = 15). All childhood HCCs developed on a background of cirrhosis resulting from tyrosinaemia type 1 (n = 4), bile salt export transporter deficiency (n = 4), biliary atresia (n = 3), and long-standing total parenteral nutrition (n = 1). HCCs in cases of tyrosinaemia type 1 always had clear cell changes, solid architecture, and only mild nuclear atypia, whereas the morphological features of HCCs in the other conditions were basically similar to those of adult HCCs. On immunostaining, all cases of childhood HCC were positive for epithelial cell adhesion molecule (EpCAM); expression was diffuse (>50% of cancer cells) in 11 cases, and particularly strong in six children, all aged <3 years. In contrast, EpCAM was only focally expressed in three cases of adult HCC (15%). EpCAM was also expressed in most fibrolamellar HCCs and hepatoblastomas, but these two neoplasms differed from childhood HCCs in the expression of CK7, β-catenin, and p53.

CONCLUSIONS

The diffuse expression of EpCAM characterizes childhood HCC, and may indicate immaturity of neoplastic cells.

Pelioid hepatocellular carcinoma in an adult Eurasian badger (Meles meles)

A mass was identified within the left lateral lobe of the liver of a 10-year-old Eurasian badger (Meles meles). The mass was friable and multilobulated, with blood-filled spaces between the lobules. Microscopically, the lesion consisted of sheets and trabeculae of neoplastic hepatocytes often forming cystic spaces containing erythrocytes, fibrin and necrotic debris. The histological appearance was consistent with hepatocellular carcinoma (HCC). Immunohistochemically, the neoplastic cells expressed cytokeratin 18 but not von Willebrand factor. Multiple intranuclear (amphophilic or acidophilic) inclusion bodies were observed in hepatocytes at the junction between the tumour and normal hepatic tissue. HCCs have also been reported in other domestic and wild animals. As hepadnavirus infection has been associated with HCC in woodchucks, further histochemical and transmission electron microscopical studies were performed; however, these demonstrated that the inclusions consisted of lipid droplets and not viral particles. To our knowledge, this is the first report of a naturally occurring HCC in a Eurasian badger.

Treatment of chronic hepatitis B in children

Chronic hepatitis B infection remains a significant health problem worldwide, and acquisition during infancy or childhood causes many of the chronic infections that are responsible for the morbidity associated with this disease. Some children with chronic hepatitis B are candidates for treatment. Two medications are currently licensed for use in children, and it is anticipated that others will be available in the next several years. This article describes rationale for treatment, patient selection and pros and cons of the current and expected therapeutic options.

Hepatocellular carcinoma in children and effect of living-donor liver transplantation on outcome

Hepatocellular carcinoma (HCC) is primarily observed in the older children and in most cases it develops in association with liver cirrhosis. Liver transplantation offers a good chance for long-term cure. To evaluate the outcome of children with HCC and the impact of living-donor orthotopic liver transplantation (OLT) on survival a retrospective review of radiographic, laboratory, pathologic, and therapeutic data in 13 children (six female and seven male) with chronic liver disease accompanied with HCC were studied. The patients were divided into two groups according to therapeutic modality: transplanted and non-transplanted patients. Kaplan-Meier survival curves in various therapeutic groups were plotted. The mean age of patients was 6.4 +/- 4.8 yr. Pediatric end-stage liver disease score was adapted to model for end-stage liver disease score for HCC and ranged between 1-44 and 18-44, respectively. The underlying liver diseases were tyrosinemia type 1 (n = 6), chronic hepatitis B infection (n = 6), glycogen storage disease type 1 (n = 1). Alfa-feto protein levels were elevated in all patients except one. Median number of tumor nodules was three (1-10), median maximal diameter of tumor nodules was 3.4 cm (0.5-8). Eleven patients were eligible for OLT whereas two patients were not eligible. Seven of the 11 patients considered for transplantation underwent living-donor OLT. Remaining four patients died while waiting on cadaveric transplant list. Overall 1 and 4-yr survival rates for all patients were 53.3 and 26.6%, respectively, and were found significantly higher in transplanted children than non-transplanted children (72%, 72% vs. 33% and 16.6%). No patient had tumor recurrence at median of 36-month follow-up after OLT. OLT is a life-saving procedure for children with chronic liver disease accompanying with HCC. Living-donor OLT avoids the risk of tumor progression and transplant ineligibility in these children.

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.

Viral diseases of the liver in children: diagnostic and differential diagnostic considerations

This review summarizes the general histologic features of acute and chronic hepatitides and highlights those morphologic findings that may suggest or be diagnostic of a specific agent or etiology. The main epidemiologic, clinical, and pathologic features of the hepatotropic viruses are discussed, with an emphasis on pediatric studies and the differential diagnosis of hepatitis in childhood.

Management of hepatitis B in children

Children with hepatitis B infection require management by physicians knowledgeable about the natural history of this disorder and experienced in the treatment of children. Selection of appropriate pediatric patients for treatment will prevent some cases of advanced liver disease later in life. New treatments under development for adults may benefit children as well, once they have been rigorously investigated in the pediatric population. Prevention of new HBV infections is an important part of management in children, and working with public health campaigns will hopefully reduce both vertical and horizontal transmission.

Detection of TT virus DNA and GB virus type C/Hepatitis G virus RNA in serum and breast milk: determination of mother-to-child transmission

To investigate the vertical transmission of the newly described TT virus (TTV), serum and breast milk samples from 46 women as well as sera from their 47 newborns were examined for the presence of TTV DNA by PCR. TTV DNA was detected in 47.8% (n = 22) of the women. All but one child born to these women were also viremic for TTV from the first sample onward. TTV DNA was found in 73.9% (n = 17) of the breast milk samples derived from TTV viremic mothers. The one TTV-negative child born to a viremic mother remained negative during follow-up, although it was breast-fed. Our data show that TTV is highly effectively transmitted from mothers to their children during pregnancy. Although the majority of breast milk samples from viremic mothers are positive by TTV PCR, there is no need to discourage women from breast-feeding, because most children are TTV viremic even before breast-feeding begins.

Interferon-alpha for viral hepatitis

IFN-alpha has emerged as a promising treatment of chronic viral hepatitis. Although therapeutic response to IFN is far from universal, efficacy has been demonstrated; and studies combining IFN-alpha with other agents, as well as trials with new preparations of IFN-alpha, are under way. Children do not represent a large part of the identified population with chronic viral hepatitis. Yet children, by simple virtue of age, are more recently infected. In addition, longer life expectancies can be expected to be associated with greater morbidity from chronic viral hepatitis. Children seem to tolerate therapy with IFN-alpha well. Treatment of children with chronic viral hepatitis should be strongly considered, with protocols designed to ascertain specific pediatric safety and efficacy.

Clinical features of hepatocellular carcinoma in the elderly: a study of 91 patients older than 70 years

In order to determine the clinical features of hepatocellular carcinoma in the elderly, a total of 622 patients with hepatocellular carcinoma, including 91 patients 70 years or older, were retrospectively analysed with reference to their ages at the time of diagnosis. The proportion of females increased and that of hepatitis B surface antigen-positive cases decreased as age increased. Tumour sizes at the time of diagnosis were somewhat smaller in the elderly than in younger patients, whereas clinical stage taking liver function into consideration was similar in the two age groups. The prognosis in the elderly patients was similar to that in the younger ones in a clinical stage-matched comparison. Furthermore, by a multivariate analysis using the Cox proportional hazards model with inclusion of age and other clinical parameters, age was not selected in the final model as an independent predictor for survival. These results indicate that elderly patients with hepatocellular carcinoma have certain clinical features different from those in younger patients and that their prognosis is not necessarily poorer than in the latter.

Pediatric liver transplantation for primary hepatocellular carcinoma associated with hepatitis virus infection

We report two cases of early primary hepatocellular carcinoma (PHC) in children, after probable maternal transmission of hepatitis B, that were treated with orthotopic liver transplantation (OLT). Both children were 8.5 years old and had elevated levels of serum alpha-feto-protein. The diagnosis of PHC was made at 8 years and confirmed histologically. Serum hepatitis B surface antigen (HBs Ag) was detected in the mothers and suggested vertical transmission. An attempt at complete liver tumor resection failed, leading to OLT. In order to prevent recurrence of the hepatitis B virus (HBV) infection, hepatitis B immunoprophylaxis was used. Two years after OLT, one child presented with recurrent HBV infection. No tumor recurrence was observed at follow-up in either of the patients. From these two cases we conclude that (1) HBV infection may play an important causal role in PHC in children, with an even shorter incubation period than that in adults; (2) close follow-up is needed for children who are HBs Ag-positive carriers; and (3) liver transplantation should be proposed early after the diagnosis of PHC, when tumor resection is not feasible.

Liver tumors in childhood: epidemiology and clinics

Childhood liver tumors have received great attention for many reasons: their vast histologic variety, uncertainty about pathogenesis and classification, recent gains in genetic understanding, relationship to antecedent diseases, and difficulties in treatment. In this paper we review the main epidemiological aspects of malignant epithelial and nonepithelial liver tumors of children, clinical aspects at presentation of disease, and diagnostic evaluation with biological and imaging studies.

Latent hepatitis B virus infection in childhood hepatocellular carcinoma. Analysis by polymerase chain reaction

The presence of hepatitis B virus (HBV) has been evaluated in liver specimens from 11 children with primary liver tumors and negative results of serologic testing for HBV markers. HBV-DNA sequences were detected by the polymerase chain reaction procedure, using different sets of oligonucleotide primers from highly conserved regions of HBV genome. Two of three children with histologic diagnosis of hepatocellular carcinoma were positive for HBV-DNA in the liver, whereas the remaining children, including six patients with hepatoblastoma, one patient with hemangioma, and one patient with hamartoma, were negative. These findings support the hypothesis of a primary role of HBV in the development of hepatocellular carcinoma in children from nonendemic areas and without overt HBV infection.

Paediatric oncology in developing countries

Paediatric oncology in developing countries is a specialty in its own right that has so far been largely neglected by the western medical profession. It has specific features of genetic cancer predisposition and of external factors influencing phenotypic cancer manifestations. We point out here some of the specific features of cancer presentation in children of developing countries.

Influence of hepatitis B virus infection and age on mode of growth of hepatocellular carcinoma

According to the extent of hepatic involvement of the tumor and that of portal vein invasion at the time of initial diagnosis, patients with hepatocellular carcinoma (HCC) were grouped into three or four groups. Correlations among the extent of hepatic involvement, extent of portal vein invasion, and prevalence of hepatitis B surface antigen (HBsAg) and age distribution were examined. The extent of hepatic involvement of the tumor and that of portal vein invasion were significantly greater in patients with positive HBsAg compared with findings in the negative patients (P less than 0.001). For cases of both positive and negative HBsAg, patients with a more extensive HCC were significantly younger. Results of the multivariate logistic regression analysis showed that hepatitis B antigenemia and younger age were statistically significant and independent positive predictors of extensive HCC. These results strongly suggest that hepatitis B surface antigenemia and age play an important role in the growth mode and the kinetics of HCC in Japanese patients.