Liver fluke-associated and sporadic cholangiocarcinoma: an immunohistochemical study of bile duct, peribiliary gland and tumour cell phenotypes

Mutational Landscape of Cholangiocarcinoma According to Different Etiologies: A Review

Recent next-generation sequencing (NGS) studies on large cohorts of cholangiocarcinoma (CCA) patients have clearly revealed the extreme intra- and inter-tumoral molecular heterogeneity that characterizes this malignancy. The lack of a stereotyped molecular signature in CCA makes the identification of actionable therapeutic targets challenging, making it mandatory to have a better understanding of the origin of such heterogeneity in order to improve the clinical outcome of these patients. Compelling evidence has shown that the CCA genomic landscape significantly differs according to anatomical subtypes and the underlying etiology, highlighting the importance of conducting molecular studies in different populations of CCA patients. Currently, some risk factors have been recognized in CCA development, while others are emerging from recent epidemiological studies. Nevertheless, the role of each etiologic factor in driving CCA genetic heterogeneity still remains unclear, and available studies are limited. In an attempt to shed more light on this issue, here we review the current literature data on the mutational spectrum of this disease according to different etiologies.

Endoscopic Ultrasound in the Diagnosis of Extrahepatic Cholangiocarcinoma: What Do We Know in 2023?

Extrahepatic cholangiocarcinoma (CCA) is a rare and aggressive type of cancer, presenting as a mass or as a biliary stricture. This review summarizes the utility of endoscopic ultrasound (EUS) in the detection, staging, and determination of the differential diagnosis, especially when no cause of bile duct dilatation is revealed by cross-sectional imaging. The EUS detection rate for distal CCAs is higher than that for the proximal CCAs. The accuracy of T staging varies between 60 and 80%, and vascular involvement is correctly assessed by conventional EUS. EUS-tissue acquisition from the primary tumors is reserved for unresectable or metastatic CCA, especially in distal strictures or mass CCAs. For proximal lesions, EUS could be performed as an adjunctive to ERCP sampling when the latter is inconclusive. EUS is not appropriate for assessing the malignant features of lymph nodes in CCAs. Lymph node EUS-tissue acquisition should be performed only if it changes the surgical decision. Perhaps the development of EUS-fine needle biopsy and the detection of molecular genetic alteration will increase the diagnostic yield in CCAs.

Development of extrahepatic bile ducts and mechanisms of tumorigenesis: Lessons from mouse models

The biliary system is a highly branched tubular network consisting of intrahepatic bile ducts (IHBDs) and extrahepatic bile ducts (EHBDs). IHBDs are derived from hepatic progenitor cells, while EHBDs originate directly from the endoderm through a separate branching morphogenetic process. Traits that are important for cancer are often found to overlap in developmental and other processes. Therefore, it has been suggested that intrahepatic cholangiocarcinomas (iCCAs) and extrahepatic cholangiocarcinomas (eCCAs) have different developmental mechanisms. While much evidence is being gathered on the mechanism of iCCAs, the evidence for eCCA is still very limited. The main reason for this is that there are very few appropriate animal models for eCCA. We can gain important insights from these animal models, particularly genetically engineered mouse models (GEMMs). GEMMs are immunocompetent and mimic human CCA subtypes with a specific mutational pattern, allowing the development of precancerous lesions, that is, biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB). This review provides a summary of the pathogenesis and mechanisms of eCCA that can be revealed by GEMMs. Furthermore, we discuss several clinical questions, such as whether BilIN and IPNB really become malignant, whether the peribiliary gland is the origin of eCCAs, and others.

Genomic alterations in cholangiocarcinoma: clinical significance and relevance to therapy

Improving the survival of patients with cholangiocarcinoma (CCA) has long proved challenging, although the treatment of this disease nowadays is on advancement. The historical invariability of survival outcomes and the limited number of agents known to be effective in the treatment of this disease has increased the number of studies designed to identify genetic targetable hits that can be efficacious for novel therapies. In this respect, the increasing feasibility of molecular profiling starting either from tumor tissue or circulating cell-free DNA (cfDNA) has led to an increased understanding of CCA biology. Intrahepatic CCA (iCCA) and extrahepatic CCA (eCCA) display different and typical patterns of actionable genomic alterations, which offer opportunity for therapeutic intervention. This review article will summarize the current knowledge on the genomic alterations of iCCA and eCCA, provide information on the main technologies for genomic profiling using either tumor tissue or cfDNA, and briefly discuss the main clinical trials with targeted agents in this disease.

Mapping of population disparities in the cholangiocarcinoma urinary metabolome

Phenotypic diversity in urinary metabolomes of different geographical populations has been recognized recently. In this study, urinary metabolic signatures from Western (United Kingdom) and South-East Asian (Thai) cholangiocarcinoma patients were characterized to understand spectral variability due to host carcinogenic processes and/or exogenous differences (nutritional, environmental and pharmaceutical). Urinary liquid chromatography mass spectroscopy (LC–MS) spectral profiles from Thai (healthy = 20 and cholangiocarcinoma = 14) and UK cohorts (healthy = 22 and cholangiocarcinoma = 10) were obtained and modelled using chemometric data analysis. Healthy metabolome disparities between the two distinct populations were primarily related to differences in dietary practices and body composition. Metabolites excreted due to drug treatment were dominant in urine specimens from cholangiocarcinoma patients, particularly in Western individuals. Urine from participants with sporadic (UK) cholangiocarcinoma contained greater levels of a nucleotide metabolite (uridine/pseudouridine). Higher relative concentrations of 7-methylguanine were observed in urine specimens from Thai cholangiocarcinoma patients. The urinary excretion of hippurate and methyladenine (gut microbial-host co-metabolites) showed a similar pattern of lower levels in patients with malignant biliary tumours from both countries. Intrinsic (body weight and body composition) and extrinsic (xenobiotic metabolism) factors were the main causes of disparities between the two populations. Regardless of the underlying aetiology, biological perturbations associated with cholangiocarcinoma urine metabolome signatures appeared to be influenced by gut microbial community metabolism. Dysregulation in nucleotide metabolism was associated with sporadic cholangiocarcinoma, possibly indicating differences in mitochondrial energy production pathways between cholangiocarcinoma tumour subtypes. Mapping population-specific metabolic disparities may aid in interpretation of disease processes and identification of candidate biomarkers.

Cell of origin in biliary tract cancers and clinical implications

Biliary tract cancers (BTCs) are aggressive epithelial malignancies that can arise at any point of the biliary tree. Albeit rare, their incidence and mortality rates have been rising steadily over the past 40 years, highlighting the need to improve current diagnostic and therapeutic strategies. BTCs show high inter- and intra-tumour heterogeneity both at the morphological and molecular level. Such complex heterogeneity poses a substantial obstacle to effective interventions. It is widely accepted that the observed heterogeneity may be the result of a complex interplay of different elements, including risk factors, distinct molecular alterations and multiple potential cells of origin. The use of genetic lineage tracing systems in experimental models has identified cholangiocytes, hepatocytes and/or progenitor-like cells as the cells of origin of BTCs. Genomic evidence in support of the distinct cell of origin hypotheses is growing. In this review, we focus on recent advances in the histopathological subtyping of BTCs, discuss current genomic evidence and outline lineage tracing studies that have contributed to the current knowledge surrounding the cell of origin of these tumours.

Serum IgG as a Marker for Opisthorchis viverrini-Associated Cholangiocarcinoma Correlated with HER2 Overexpression

BACKGROUND

Serum antibody for Opisthorchis viverrini (OV) is strong evidence for a history of OV infection in people. Currently, no studies have examined whether varying cholangiocarcinoma (CCA) prevalence levels are linked to previous OV infection nor have they provided comprehensive assessment and characterization of OV-associated CCA.

OBJECTIVE

Our study examined the prevalence of serum IgG antibodies for OV-positive CCA cases and determined whether there were correlations of IgG antibodies with histopathologic features, HER2, PD-L1, and FGFR2 expression, as well as their roles on the patients' survival.

METHODS

The study involved 221 CCA surgical patients at Khon Kaen University Hospital, Thailand, from 2005 to 2017. Serum specimens were tested for OV IgG by ELISA. CCA tissue microarrays were used to examined for HER2, PD-L1, and FGFR2 expression. Logistic regression was used to investigate an association between factors and IgG. Cox regression was used to determine factors that affected CCA patient survival.

RESULTS

IgG for OV were positive in 162 cases, and the prevalence was 73.3% (95% CI=68.0-78.7). About three quarters (78.3%) had large duct type tumors and concomitant intraductal papillary neoplasm of bile ducts (IPNB) occurred in 92 (50%) cases. HER2 expression was positive in 94 (61.4%) cases. Positive PD-L1 and FGFR2 expression occurred in 125 (83.9%) and 100 (67.1%) cases. IgG for OV had no significant correlation to any histological feature but had significant correlation with HER2 overexpression with adjusted OR=2.32 (95% CI=1.09-4.96, P=0.03). Cases of CCA with OV IgG positive had a significantly poor prognosis with adjusted HR=1.66 (95% CI=1.13-2.43, P=0.01).

CONCLUSION

We found a high prevalence of serum IgG for OV-positive CCA patients and a correlation with overexpression of HER2. Moreover, IgG for OV and HER2 expression indicated poor survival of CCA. Therefore, future clinical studies for anti-HER2 treatments should focus on OV-associated CCA.

Translating Biomarkers of Cholangiocarcinoma for Theranosis: A Systematic Review

Cholangiocarcinoma (CCA) is a rare disease with poor outcomes and limited research efforts into novel treatment options. A systematic review of CCA biomarkers was undertaken to identify promising biomarkers that may be used for theranosis (therapy and diagnosis). MEDLINE/EMBASE databases (1996-2019) were systematically searched using two strategies to identify biomarker studies of CCA. The PANTHER Go-Slim classification system and STRING network version 11.0 were used to interrogate the identified biomarkers. The TArget Selection Criteria for Theranosis (TASC-T) score was used to rank identified proteins as potential targetable biomarkers for theranosis. The following proteins scored the highest, CA9, CLDN18, TNC, MMP9, and EGFR, and they were evaluated in detail. None of these biomarkers had high sensitivity or specificity for CCA but have potential for theranosis. This review is unique in that it describes the process of selecting suitable markers for theranosis, which is also applicable to other diseases. This has highlighted existing validated markers of CCA that can be used for active tumor targeting for the future development of targeted theranostic delivery systems. It also emphasizes the relevance of bioinformatics in aiding the search for validated biomarkers that could be repurposed for theranosis.

Anatomical, histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin-producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub-classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho-molecular groups can currently be discriminated. Large-duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2-fusions are typically seen in small-duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.

Peribiliary Glands as the Cellular Origin of Biliary Tract Cancer

The identification of the cellular origin of cancer is important for our understanding of the mechanisms regulating carcinogenesis, thus the cellular origin of cholangiocarcinoma (CCA) is a current topic of interest. Although CCA has been considered to originate from biliary epithelial cells, recent studies have suggested that multiple cell types can develop into CCA. With regard to the hilar and extrahepatic bile ducts, peribiliary glands (PBGs), a potential stem cell niche of biliary epithelial cells, have attracted attention as the cellular origin of biliary tract cancer. Recent histopathological and experimental studies have suggested that some kinds of inflammation-induced CCA and intraductal papillary neoplasms of the bile duct are more likely to originate from PBGs. During inflammation-mediated cholangiocarcinogenesis, the biliary epithelial injury-induced regenerative response by PBGs is considered a key process. Thus, in this review, we discuss recent advances in our understanding of cholangiocarcinogenesis from the viewpoint of inflammation and the cellular origin of CCA, especially focusing on PBGs.

Biliary epithelial injury-induced regenerative response by IL-33 promotes cholangiocarcinogenesis from peribiliary glands

The carcinogenic mechanism of extrahepatic cholangiocarcinoma (ECC) is unclear, due at least in part to the lack of an appropriate mouse model. Because human studies have reported frequent genetic alterations in the Ras- and TGFβ/SMAD-signaling pathways in ECC, mice with tamoxifen-inducible, duct-cell-specific Kras activation and a TGFβ receptor type 2 (TGFβR2) deletion were first generated by crossing LSL-Kras^G12D , Tgfbr2^flox/flox , and K19^CreERT mice (KT-K19^CreERT ). However, KT-K19^CreERT mice showed only mild hyperplasia of biliary epithelial cells (BECs) in the extrahepatic bile duct (EHBD) and died within 7 wk, probably a result of lung adenocarcinomas. Next, to analyze the additional effect of E-cadherin loss, KT-K19^CreERT mice were crossed with CDH1^flox/flox mice (KTC-K19^CreERT ). Surprisingly, KTC-K19^CreERT mice exhibited a markedly thickened EHBD wall accompanied by a swollen gallbladder within 4 wk after tamoxifen administration. Histologically, invasive periductal infiltrating-type ECC with lymphatic metastasis was observed. Time-course analysis of EHBD revealed that recombined BECs lining the bile duct lumen detached due to E-cadherin loss, whereas recombined cells could survive in the peribiliary glands (PBGs), which are considered a BEC stem-cell niche. Detached dying BECs released high levels of IL-33, as determined by microarray analysis using biliary organoids, and stimulated inflammation and a regenerative response by PBGs, leading eventually to ECC development. Cell lineage tracing suggested PBGs as the cellular origin of ECC. IL-33 cooperated with Kras and TGFβR2 mutations in the development of ECC, and anti-IL-33 treatment suppressed ECC development significantly. Thus, this mouse model provided insight into the carcinogenic mechanisms, cellular origin, and potential therapeutic targets of ECC.

Revealing gene clusters associated with the development of cholangiocarcinoma, based on a time series analysis

Cholangiocarcinoma (CC) is a rapidly lethal malignancy and currently is considered to be incurable. Biomarkers related to the development of CC remain unclear. The present study aimed to identify differentially expressed genes (DEGs) between normal tissue and intrahepatic CC, as well as specific gene expression patterns that changed together with the development of CC. By using a two‑way analysis of variance test, the biomarkers that could distinguish between normal tissue and intrahepatic CC dissected from different days were identified. A k‑means cluster method was used to identify gene clusters associated with the development of CC according to their changing expression pattern. Functional enrichment analysis was used to infer the function of each of the gene sets. A time series analysis was constructed to reveal gene signatures that were associated with the development of CC based on gene expression profile changes. Genes related to CC were shown to be involved in 'mitochondrion' and 'focal adhesion'. Three interesting gene groups were identified by the k‑means cluster method. Gene clusters with a unique expression pattern are related with the development of CC. The data of this study will facilitate novel discoveries regarding the genetic study of CC by further work.

Occult hepatitis B virus infection in Chinese cryptogenic intrahepatic cholangiocarcinoma patient population

BACKGROUND

There is no information available about occult hepatitis B virus (HBV) infection (OBI) in individuals with intrahepatic cholangiocarcinoma (ICC).

GOALS

To investigate the correlation between OBI and ICC.

STUDY

A retrospective case-control study was conducted. The cases were 183 cryptogenic ICC patients (group I), and the controls were 549 healthy individuals (group II). The cases and controls were matched for age, sex, and inhabitancy. Adjusted odds ratios and 95% confidence intervals were calculated. Intrahepatic total HBV DNA in 63 paraffin-embedded samples was collected from patients in group I (n=44), HBV-associated ICC patients (n=3), and hepatic cavernous hemangioma patients with seronegative HBsAg (hepatitis B S antigen) (group III; n=16). We determined the levels of serum and intrahepatic HBV DNA and compared the level of intrahepatic HBV DNA in 44 cryptogenic patients from group I with the level in the patients from group III.

RESULTS

Compared with group II, group I had a lower prevalence of anti-HBs (antibody against HBsAg) and a higher prevalence of anti-HBe (antibody against hepatitis B e antigen) and anti-HBc (antibody against hepatitis B c antigen). Multivariate analysis confirmed that anti-HBe and anti-HBc positivity were associated with ICC. The odds ratios and 95% confidence intervals for anti-HBe and anti-HBc were 2.482 and 1.482-4.158, 4.556 and 2.938-7.066, respectively. Compared with group III, cryptogenic ICC cases showed more frequent detection of intrahepatic total HBV DNA (63.64% vs. 18.75%, P=0.002).

CONCLUSIONS

OBI may represent an important risk factor for ICC. HBsAg seroclearance does not signify eradication of HBV and may not entirely prevent the development of ICC.

Differences in immunohistochemical biomarkers between intra- and extrahepatic cholangiocarcinoma: a systematic review and meta-analysis

BACKGROUND AND AIM

Cholangiocarcinomas of different locations differ in growth patterns, symptoms, treatment response, and survival. Still, they are regarded in many studies as a uniform malignancy. Because intra- (iCCA) and extrahepatic (eCCA) cholangiocarcinoma display such differences, we performed a systematic review and meta-analysis to analyze differences in the immunohistochemical profile of these tumors.

METHODS

In February 2014, we searched the two main medical literature databases MEDLINE and EMBASE. We extracted risk ratios and 95% confidence intervals from the identified studies and performed random-effects model meta-analyses in accordance with PRISMA and REMARK guidelines.

RESULTS

A total of 54 cohort studies, including 4458 patients and studying 102 individual markers met the inclusion criteria. Of the 57 markers that were evaluated in more than 30 iCCA and eCCA patients, 18 showed a statistically significant difference in expression between iCCA and eCCA. Biomarkers expressed differently between iCCA and eCCA included potential targets of therapy: EGFR, c-erbB-2 and VEGF-A. Several markers showed no statistical difference but large 95% confidence intervals, suggesting insufficient sample size.

CONCLUSIONS

This systematic review shows differences in marker expression between iCCA and eCCA. Consequently, patients with iCCA and eCCA may benefit from different treatment strategies.

The challenge of cholangiocarcinoma: dissecting the molecular mechanisms of an insidious cancer

Cholangiocarcinoma is a fatal cancer of the biliary epithelium and has an incidence that is increasing worldwide. Survival beyond a year of diagnosis is less than 5%, and therapeutic options are few. Known risk factors include biliary diseases such as primary sclerosing cholangitis and parasitic infestation of the biliary tree, but most cases are not associated with any of these underlying diseases. Numerous in vitro and in vivo models, as well as novel analytical techniques for human samples, are helping to delineate the many pathways implicated in this disease, albeit at a frustratingly slow pace. As yet, however, none of these studies has been translated into improved patient outcome and, overall, the pathophysiology of cholangiocarcinoma is still poorly understood. There remains an urgent need for new approaches and models to improve management of this insidious and devastating disease. In this review, we take a bedside-to-bench approach to discussing cholangiocarcinoma and outline research opportunities for the future in this field.

Viable metacercariae of Opisthorchis viverrini in northeastern Thai cyprinid fish dishes--as part of a rational program for control of O. viverrini-associated cholangiocarcinoma

Among the various types of chronic helminthic infections, only schistosomiasis hematobium, opisthorchiasis, and clonorchiasis in a long-standing inflammation are found to be causative agents of cancer. Opisthorchiasis and Opisthorchis viverrini-associated bile duct cancer are prevalent among the residents in northeastern Thailand, who prefer consuming raw or improperly cooked cyprinid fish. Although numerous studies have reported on the presence of O. viverrini metacercariae in freshwater cyprinid fishes, none of the data has been derived directly from cyprinid fish dishes. Here, we have demonstrated the presence of viable metacercariae in a number of cyprinid fish dishes that are among the favorite foods of northeastern Thais. Traditional salt-fermented and grilled cyprinid fish were found to be safe to consume, but not raw fish salad or cyprinid fish fermented in sticky rice for 69 h. This information could be used as part of a rational and sustainable control program for O. viverrini-associated bile duct cancer.

The biliary tree--a reservoir of multipotent stem cells

The biliary tree is composed of intrahepatic and extrahepatic bile ducts, lined by mature epithelial cells called cholangiocytes, and contains peribiliary glands deep within the duct walls. Branch points, such as the cystic duct, perihilar and periampullar regions, contain high numbers of these glands. Peribiliary glands contain multipotent stem cells, which self-replicate and can differentiate into hepatocytes, cholangiocytes or pancreatic islets, depending on the microenvironment. Similar cells-presumably committed progenitor cells-are found in the gallbladder (which lacks peribiliary glands). The stem and progenitor cell characteristics indicate a common embryological origin for the liver, biliary tree and pancreas, which has implications for regenerative medicine as well as the pathophysiology and oncogenesis of midgut organs. This Perspectives article describes a hypothetical model of cell lineages starting in the duodenum and extending to the liver and pancreas, and thought to contribute to ongoing organogenesis throughout life.

Infection with the carcinogenic human liver fluke, Opisthorchis viverrini

Throughout Southeast Asia there is a strikingly high incidence of cholangiocarcinoma (CCA--hepatic cancer of the bile duct epithelium), particularly in people from rural settings in Laos and Northeast Thailand who are infected with the liver fluke, Opisthorchis viverrini, one of only three carcinogenic eukaryotic pathogens. More ubiquitous carcinogenic microbes, such as Helicobacter pylori, induce cancer in less than 1% of infected people, while as many as one-sixth of people with opisthorchiasis will develop CCA. The mechanisms by which O. viverrini causes cancer are multi-factorial, involving mechanical irritation from the activities and movements of the flukes, immunopathology, dietary nitrosamines and the secretion of parasite proteins that promote a tumourigenic environment. Genomic and proteomic studies of the liver fluke secretome have accelerated the discovery of parasite proteins with known/potential roles in pathogenesis and tumourigenesis, establishing a framework towards understanding, and ultimately preventing, the morbidity and mortality attributed to this highly carcinogenic parasite.

An immunohistochemical profile of the so-called bile duct adenoma: clues to pathogenesis

The so-called bile duct adenoma and peribiliary glands are characterized by the expression of two foregut antigens (designated D10 and 1F6) and secretion of acid mucin. On account of this similarity in phenotype and their frequent close association with a large caliber bile duct, it was earlier suggested that bile duct adenoma represent a peribiliary gland hamartoma. Here, we compare the expression of 13 tissue antigens in bile duct adenomas, other benign bile duct lesions, and various foregut-derived tissues, to further investigate the bile duct adenoma phenotype and pathogenesis. Antibodies to 4 intestinal mucins, 3 cytokeratins, and CDX2, were not informative. Five foregut antigens (D10, 1F6, MUC6, MUC5AC, and TFF2) and secretion of acid mucin were of use in distinguishing bile duct adenoma from other hepatic lesions. 1F6 and MUC6 were normally present in bile ductules and canals of Hering, whereas the epithelium lining the larger bile ducts stained focally for D10, MUC5AC, MUC6, or TFF2 in, respectively, 21%, 36%, 43%, and 100% of the livers examined. Thirty-six bile duct adenomas examined were distinguished by expression of MUC6 (94% of bile duct adenoma), MUC5AC (90%), TFF2 (80%), D10 (67%), and 1F6 (61%), and varying degrees of acid mucin secretion (100%). Of 30 bile duct adenoma tested for all 5 antigens, 40% expressed all 5, 27% expressed 4, 17% expressed 3, 13% expressed 2, and 1 expressed only MUC6. Peribiliary glands invariably expressed D10, 1F6, MUC6, and TFF2, and showed acid mucin secretion, with MUC5AC present in the inflamed peribiliary glands of 3/4 livers with recurrent pyogenic cholangitis, but none of the glands of the other 23 normal or diseased livers tested. The acini of pyloric gland metaplasia in gallbladder and terminal ileum also stained for D10, 1F6, MUC6, and TFF2, with MUC5AC focally present in the gastric foveolar metaplasia overlying the pyloric gland metaplasia but not in the metaplastic glands. MUC6 was expressed in 92% of ductular reactions, 1F6 in 42%, and D10 in 25%. Focal expression of MUC6, or TFF2 was observed in 1 or 2 examples of 14 von Meyenburg complexes and 6 polycystic livers, with staining for acid mucin generally obvious only in the glycocalyx of the epithelium of these two types of lesions. The distinguishing feature of so-called bile duct adenoma is their display of the same phenotype as pyloric gland metaplasia. It is concluded that they develop as a localized biliary healing response equivalent to the function of a peribiliary gland or pyloric gland metaplasia in the foregut.

Hepatitis B virus-associated intrahepatic cholangiocarcinoma and hepatocellular carcinoma may hold common disease process for carcinogenesis

AIMS

To evaluate potential risk factors for intrahepatic cholangiocarcinoma (ICC) and analyse clinicopathologic characteristics of ICC patients with seropositive hepatitis B surface antigen (HBsAg).

METHODS

A retrospective case-control study was conducted. Cases were 317 ICC patients referred to the Eastern Hepatobiliary Surgery Hospital in China between 2003 and 2006. Controls were 634 healthy individuals. Adjusted odds ratios (ORs) were calculated in logistic regression analysis. Among 317 consecutively enrolled ICC patients, 154 patients were seropositive HBsAg (48.6%). We compared clinicopathologic characteristics of these patients (group I) with ICC patients seronegative for HBsAg (group II; n=163) and compared the age and sex distributions of patients in group I with randomly selected hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) (group III; n=1,140).

RESULTS

Compared with the controls, ICC patients had a high prevalence of seropositive HBsAg, cirrhosis, hepatolithiasis and hepatic schistosomiasis. Compared with seronegative-HBsAg ICC patients, seropositive-HBsAg ICC patients were younger, more frequently male and had a higher proportion of abnormal aminotransferase and serum alpha-fetoprotein (AFP) level, histological inflammation and cirrhosis, right-lobe focus, poor tumour differentiation, tumour encapsulation and microvascular invasion; had a lower proportion of abnormal serum carbohydrate antigen 19-9 (CA19-9) level and lymphatic metastasis. The age and sex distribution profiles were nearly identical between seropositive-HBsAg ICC patients and HBV-associated HCC patients.

CONCLUSIONS

The HBV infection, cirrhosis, hepatolithiasis and hepatic schistosomiasis may be potential risk factors for ICC. HBV-associated ICC shares many clinicopathological similarities with HBV-associated HCC. The result indicated HBV-associated ICC and HBV-associated HCC may hold common disease process for carcinogenesis.

Etiological and clinicopathologic characteristics of intrahepatic cholangiocarcinoma in young patients

AIM: To investigate the prevalence, risk factors, and clinicopathologic characteristics of intrahepatic cholangiocarcinoma (ICC) in young patients.

METHODS: A retrospective analysis was performed in ICC patients referred to the Eastern Hepatobiliary Surgery Hospital in Shanghai, China. Among 317 consecutively enrolled patients, 40 patients were aged ≤ 40 years (12.61%). We compared the risk factors and clinicopathologic characteristics of these patients (group I: n = 40) with those aged > 40 years (group II: n = 277).

RESULTS: Group I had distinct features compared with group II, including a low frequency of hepatolithiasis (P = 0.000); a high positive rate of serum hepatitis B surface antigen (P = 0.000) and hepatitis B virus (HBV)-associated cirrhosis (P = 0.038); a high frequency of α-fetoprotein (> 400 μg/L) (P = 0.011); a low frequency of carbohydrate antigen 19-9 (> 37 U/mL) (P = 0.017); and a high frequency of liver histological inflammation (P = 0.002). Although there was no significant difference between the two groups in regards to hepatic schistosomiasis, alcohol-associated cirrhosis and cirrhosis due to other causes (P > 0.05), they only occurred in the elderly group.

CONCLUSION: The risk factors are significantly different between young and elderly ICC patients. HBV and HBV-associated cirrhosis are the most important risk factors for young ICC patients.

Inflammation and carcinogenesis of the biliary tract: update on endoscopic treatment

Both diagnosis and treatment of cholangiocarcinoma are suboptimal. From the former standpoint, fluorescence in situ hybridization, direct cholangioscopy, endocystoscopy, and optical coherence tomography are just a few of the myriad technologies being studied or employed to improve diagnostic yield. From the latter standpoint, most series suggest that fewer than 1 third of patients are resectable for cure, although liver transplantation has increasingly been used in a subset of cholangiocarcinoma patients with extrahepatic disease. Palliation has included chemotherapy which is of dubious value in most series. Instead, a majority of therapies have addressed mechanisms to improve biliary drainage to delay and preclude hepatic failure and minimize the risk of cholangitis. Although the latter has been accomplished with surgery and attempted with external beam irradiation and brachytherapy, percutaneous and/or endoscopic drainage are the most commonly employed methods in widespread use. There are prospective, randomized studies that suggest that bilateral stenting is associated with improved outcomes in bifurcation lesions if plastic stents are placed, that percutaneous transhepatic biliary drainage is more successful than endoscopic stenting in Klatskin tumors, that self-expandable biliary stents have prolonged patency compared with plastic prostheses, and that, if approached with computed tomography and magnetic resonance imaging guidance to preclude contamination of the contralateral undrained system, outcomes are comparable in patients treated with unilateral as opposed to bilateral self-expandable metal stents. There is a single prospective, randomized study suggesting that patients treated with endoscopic or percutaneous stenting in conjunction with photodynamic therapy have prolonged survival compared with stent placement alone.

Effect of extracellular matrix composition on airway epithelial cell and fibroblast structure: implications for airway remodeling in asthma

BACKGROUND

Airway remodeling in asthma is characterized by structural changes to the airways including extracellular matrix (ECM) deposition and epithelial metaplasia. Extracellular matrix deposition in the subepithelial region may play an important role in modulation of epithelial cell and fibroblast structure and function because it lies in immediate contact with these cell types and exists within the functional epithelial mesenchymal trophic unit.

OBJECTIVE

To investigate the effect of aberrant ECM components on airway epithelial cells and fibroblasts and the relationship among subepithelial ECM deposition, other remodeling changes, and airway hyperresponsiveness.

METHODS

BEAS-2B human airway epithelial cells and WI-38 human airway fibroblast cells were cultured on various ECM protein substrates (Matrigel, representing normal basement membrane matrix, or aberrant matrix proteins collagen I, collagen III, and fibronectin). Airway remodeling changes were determined using morphometry in sections from a murine model of chronic allergic airway disease. Airway reactivity to methacholine was determined, and these parameters correlated.

RESULTS

Abnormal ECM substrates induced epithelial and fibroblast proliferation and altered the cell morphology of both human airway epithelial cells and fibroblasts when compared with normal basement membrane ECM. Subepithelial matrix deposition in the mouse correlated with epithelial thickness, but only weak correlations were noted among the other parameters.

CONCLUSIONS

We have demonstrated that ECM may affect the growth of airway epithelial cells and fibroblasts in vitro and may influence epithelial thickness in the mouse. These findings may have implications for understanding the pathogenesis of asthma and future therapeutic targeting of airway remodeling.

Cholangiocarcinoma: lessons from Thailand

PURPOSE OF REVIEW

To present the background of liver fluke-associated cholangiocarcinoma in Thailand focusing on recent epidemiological data and pathogenesis of this bile duct cancer.

RECENT FINDINGS

More systematic tumor registration in Thailand nowadays uncovers new high-incidence areas that are confined to not only the northeastern part but also some provinces in northern Thailand. The link between the liver fluke, Opisthorchis viverrini, and cholangiocarcinoma, particularly in terms of cellular and molecular pathogenesis, is further elucidated.

SUMMARY

Thailand is still the country with the highest incidence of cholangiocarcinoma in the world. Liver fluke induces chronic inflammation leading to oxidative DNA damage of the infected biliary epithelium and malignant transformation. Eradication of the fluke and identification of high-risk populations are urgently needed.

Perihilar cholangiocarcinoma arising in hepatitis C virus-related liver cirrhosis with hepatocellular carcinoma

Liver cirrhosis is reportedly one of the conditions preceding peripheral-type intrahepatic cholangiocarcinoma but not hilar/perihilar cholangiocarcinoma. Herein, we report a case of perihilar cholangiocarcinoma arising in a hepatitis C virus-related cirrhotic liver. The patient was a 69-year-old man. He was diagnosed with hepatitis C virus-related chronic hepatitis at the age of 56 years, and 9 years later, multiple hepatocellular carcinomas were detected by imaging modalities. Despite treatments, including chemotherapy, he died of hepatic failure at the age of 69 years. At autopsy, in addition to multiple nodules of hepatocellular carcinoma, we found a white mucinous and fibrous tumor spreading from the hepatic hilum to the periphery along the left lateral segmental bile ducts in the advanced cirrhotic liver. This tumor was histologically a cholangiocarcinoma that involved mainly the peribiliary glands and showed variable cystic dilation, suggesting that it might have been derived from these peribiliary glands. Immunohistochemically, the cholangiocarcinoma cells were positive for cytokeratin 7 and mucin core protein 1, and negative for cytokeratin 20 and mucin core protein 2. Hilar/perihilar cholangiocarcinoma arising in hepatitis C virus-related liver cirrhosis has rarely been reported. This case warrants further studies to clarify the possible involvement of hepatitis C virus in tumorigenesis of hilar/perihilar cholangiocarcinoma.