K-ras point mutations in cancerous and noncancerous biliary epithelium in patients with pancreaticobiliary maljunction

Diagnostic usefulness of SpyGlass in intracholecystic papillary neoplasm with pancreaticobiliary maljunction: a case report and comparison with conventional gallbladder cancer with pancreaticobiliary maljunction

BACKGROUND

Intracholecystic papillary neoplasm (ICPN) is one of the precursors of gallbladder cancer defined in the 2010 World Health Organization classification of tumors. We herein report ICPN with pancreaticobiliary maljunction (PBM), which is a high-risk factor for biliary cancer.

CASE PRESENTATION

A 57-year-old female presented with abdominal pain. Computed tomography showed a swollen appendix and gallbladder nodules with bile duct dilatation. Endoscopic ultrasonography revealed a gallbladder tumor spreading into the cystic duct confluence accompanying PBM. Based on papillary tumors around the cystic duct detected using the SpyGlass DS II Direct Visualization System (SpyGlass DS), ICPN was suspected. We performed extended cholecystectomy, extrahepatic bile duct resection, and appendectomy with a diagnosis of ICPN and PBM. The pathological diagnosis was ICPN (90 × 50 mm) with high-grade dysplasia spreading into the common bile duct. The absence of residual cancer in the resected specimen was pathologically confirmed. P53 staining was totally negative in both the tumor and normal epithelium. The overexpression of CTNNB1 was not observed.

CONCLUSIONS

We encountered a patient with a very rare gallbladder tumor, ICPN with PBM. SpyGlass DS contributed to a precise assessment of the extent of the tumor as well as a qualitative diagnosis.

Liquid Biopsy from Bile-Circulating Tumor DNA in Patients with Biliary Tract Cancer

Simple Summary

Utilization of cell free DNA for diagnosing and monitoring patients with biliary tract cancers is emerging and promising. The strength of the present study is in its description of a novel approach using bile rather than blood or tissue samples, which is particularly relevant in biliary tract cancers. This paper largely serves as a proof of concept that ctDNA from bile is potentially feasible.

Abstract

Although liquid biopsy of blood is useful for cancer diagnosis and prediction of prognosis, diagnostic and prognostic value of ctDNA in bile fluid for BTCs are not clear yet. To determine whether liquid biopsy for circulating tumor DNA (ctDNA) can replace tissue biopsy when assessing somatic mutations in biliary tract cancers (BTCs). Bile samples were obtained from 42 patients with BTC. Matched formalin-fixed paraffin-embedded (FFPE) samples were obtained from 20 of these patients and matched plasma samples from 16 of them. Droplet digital PCR (ddPCR) was used for detection KRAS somatic mutation. KRAS mutations were identified in the bile ctDNA of 20 of 42 (48%) patients. Patients with mutant KRAS showed significantly worse survival than those with wild-type KRAS (2-year survival rates: 0% vs. 55.5%, respectively; p = 0.018). There was 80.0% mutational concordance between the paired bile ctDNA and FFPE samples, and 42.9% between the plasma and FFPE samples. On transcriptomic sequencing of one set of paired bile and FFPE samples, expression level of KRAS-associated signaling oncogenes in the bile and tissue samples showed a strong positive correlation (r = 0.991, p < 0.001). Liquid biopsy of bile reliably detect mutational variants within the bile ctDNA of BTC patients. These results suggest that bile is an effective biopsy fluid for ctDNA analysis.

Kras-driven heterotopic tumor development from hepatobiliary organoids

Cancers arising from the biliary tract are refractory to conventional therapies, requiring the development of novel therapeutics. However, only a limited number of genetically engineered mouse models have been created, partly because of time-consuming work required. Besides, liver-specific gene manipulation mostly resulted in concurrent development of hepatocellular carcinoma, another type of liver cancer, and gallbladder-restricted gene targeting is still not feasible. Consequently, establishment of cancer type-specific disease modeling remains a technical challenge. To address this issue, we took an alternative cell-based approach to quickly induce tumorigenesis ex vivo. Specifically, murine primary organoids from liver and gallbladder were transduced with lentiviral vectors to reconstitute genetic alterations common in biliary tract cancers, followed by inoculation in immunodeficient mice. Although any single genetic alteration did not induce tumors, mutant Kras and repression of major tumor suppressors cooperated for tumor development within 2 months. Induced lesions varied among normal, dysplastic and papillary lesions to adenocarcinoma, recapitulating multistep tumorigenesis even in a heterotopic situation. We further demonstrated that two putative oncogenes in intrahepatic cholangiocellular carcinoma, mutant Pik3ca and FGFR2-AHCYL1 fusion, were rather modest drivers for liver-derived organoids, probably requiring additional mutations or hepatic niche to robustly induce full-blown tumors. Thus, we showed that cancer cells could be readily generated from primary cells in the biliary tract, at least in cases where genetic factors play dominant roles. Collectively, this study will likely contribute to gaining mechanistic insights into biliary carcinogenesis and providing valuable resources for drug discovery.

Identification of MAP kinase pathways as therapeutic targets in gallbladder carcinoma using targeted parallel sequencing

The aim of this study was to profile somatic mutation spectrum in gallbladder cancers (GBCs), and determine the role of MAP kinase pathway in GBC by a series of in vitro and in vivo studies. We performed targeted massively parallel sequencing of DNA isolated from GBCs and matched blood from 14 GBC patients to search for mutations in 504 genes commonly altered in human cancers. We identified recurrent mutations enriched in several major signaling pathways including MAP kinase, Wnt/β-catenin and NF-κB pathways. Immunohistochemistry analysis further validated overactivation of MAP kinase and Wnt pathways in a panel of GBC samples. By treating GBC cells with MEK inhibitor trametinib, we found that trametinib not only dramatically inhibited the activity of MAPK/ERK pathway, but also blocked the Wnt/β-catenin signaling through decreasing β-catenin expression or suppressing nucleus translocation of β-catenin. Moreover, trametinib inhibited the proliferation of GBC cell in a dose- and time-dependent manner, induced GBC cell apoptosis, and inhibited GBC cell migration and invasion. Growth of xenograft tumors derived from GBC cell line NOZ in nude mice was also significantly inhibited by trametinib. Our data highlight the critical role of MAP kinase pathways in GBC pathogenesis, and may represent therapeutic targets for this cancer.

Synchronous primary gallbladder and pancreatic cancer associated with congenital biliary dilatation and pancreaticobiliary maljunction

Introduction

Synchronous double cancer of the gallbladder and pancreas that is associated with congenital biliary dilatation (CBD) and pancreaticobiliary maljunction (PBM) is extremely rare. PBM is frequently reported in Asia, particularly in Japan. We report a surgical case of synchronous double cancer in a patient with primary gallbladder and pancreatic cancer.

Presentation of case

A 72-year-old woman with epigastralgia underwent subtotal stomach-preserving pancreaticoduodenectomy and gallbladder bed resection for synchronous primary gallbladder and pancreatic head cancer. Histopathological examination revealed moderately differentiated ductal adenocarcinoma of the pancreatic head and well-differentiated tubular adenocarcinoma at the bottom of the gallbladder.

Conclusion

Synchronous gallbladder and pancreatic cancer is extremely rare. It is necessary to determine the optimal surgical course taking into consideration the degree of tumor progression. This is the second case of synchronous primary gallbladder and pancreatic cancer associated with CBD accompanied by PBM.

KrasG12D upregulates Notch signaling to induce gallbladder tumorigenesis in mice

Background

Kras mutations and increased Notch activation occur frequently in gallbladder cancer. However, their roles in gallbladder carcinogenesis have not been defined. This study was aimed at determining whether expression of mutant Kras was sufficient to induce gallbladder carcinoma and whether Notch deregulation played a role in this context.

Methods

We determined Cre recombination activity of Pdx1-Cre in the gallbladder using a reporter strain and examined gallbladder tumor development in the Kras^{LSL- G12D/+};Pdx1-Cre mice. We analyzed expression of Notch pathway genes in the mouse gallbladder by immunohistochemistry, quantitative RT-PCR, and Western blot analysis. We also determined the effect of Jag1 deletion on Kras-induced gallbladder tumor development.

Results

Pdx1-Cre exhibits robust recombination activity in the gallbladder epithelium. Kras^LSL-G12D/+;Pdx1-Cre mice form early onset adenoma in the gallbladder and adjacent biliary tract with complete penetrance, albeit short of invasive adenocarcinoma. Kras^G12D upregulates expressions of Notch2, Notch3, Notch4, Jag1 and downstream target genes Hes1, Hey1 and Hey2, and deletion of Jag1 partially suppresses Kras^G12D-induced adenoma development.

Conclusions

Kras^G12D induces gallbladder adenoma and Notch plays a key role in Kras-initiated gallbladder tumorigenesis.

Congenital choledochal malformation: search for a marker of epithelial instability

PURPOSE

There is a predisposition to the development of malignancy in congenital choledochal malformation (CCM) although the degree of risk is unknown. We investigated the role of CA19-9 in bile and the MIB-1 (Ki-67) epithelial proliferation index as markers of an at risk choledochal epithelium at the time of definitive surgery.

METHODS

Bile collected at surgery was analyzed for levels of amylase (as a surrogate of pancreatic reflux) and CA19-9. Immunohistochemical staining for CA19-9 and MIB-1 index (expressed as %) was performed on resected specimens. Data are quoted as median (IQR) and differences assessed using non-parametric statistics. A P value of 0.05 was regarded as significant.

RESULTS

Our study group consisted of 78 children with CCM (Type 1 fusiform, n=34; Type 1 cystic, n=30 and Type 4, n=14). Median bile CA19-9 was 159,400 (6-1×10(6)) kU/L. There was no correlation with bile amylase (P=0.49) or biliary pressure (P=0.17) but modest correlation with bilirubin (rs=0.24; P=0.02). In contrast, bile amylase was correlated with plasma γ-glutamyl transpeptidase (P=0.02), alkaline phosphatase (P=0.05) and aspartate aminotransferase (P=0.02); and inversely correlated with biliary pressure (rs=-0.38; P<0.0008). Epithelial expression of CA19-9 and MIB-1 was assessed in 43 specimens. CA19-9 was diffusely expressed on all choledochal epithelium. MIB-1 expression was divided into: high expression (>40%) n=3; moderate (20-40%) n=5, low (6-20%) n=7 and very low (≤5%) n=28. There was no correlation with choledochal pressure (P=0.87), CA19-9 (P=0.51) or bile amylase (P=0.55).

CONCLUSION

Biliary CA19-9 levels were grossly (and unexpectedly) raised in choledochal malformation and appear to arise from biliary rather than pancreatic epithelium. MIB-1 confirms that a small proportion (19%) has marked epithelial proliferation but no clinical correlates could be identified.

The effects of miR-1207-5p expression in peripheral blood on cisplatin-based chemosensitivity of primary gallbladder carcinoma

OBJECTIVE

The aim of this study was to investigate the association between miR-1207-5p expression in peripheral blood and the chemosensitivity of primary gallbladder carcinoma (PGBC).

METHODS

A total of 85 patients with PGBC undergoing preoperative chemotherapy were divided into effective (n=18) and ineffective (n=67) groups. Another 70 healthy individuals were selected as the control group. An miR-1207-5p mimic (mimic group), an inhibitor (inhibitor group), and a negative control (NC group) sequence were transfected into human gallbladder carcinoma GBC-SD cells. Real-time quantitative polymerase chain reaction was used to determine miR-1207-5p expression. After 48 hours of cisplatin treatment, CCK-8 method was used to detect cell proliferation and flow cytometry were performed to examine cell apoptosis.

RESULTS

miR-1207-5p expression in peripheral blood was significantly associated with tumor node metastasis staging of PGBC (P<0.05). Before chemotherapy, miR-1207-5p expression in patients was higher than in healthy individuals (P<0.05). After chemotherapy, the effective group had lower miR-1207-5p expression than the ineffective group (P<0.05). The rates of positive expression of Ki67 protein in the effective group were significantly lower than those in the ineffective group (P<0.05). Receiver operating characteristic curves showed that the area under curve, sensitivity, and specificity of miR-1207-5p used to diagnose PGBC were 0.898, 77.6%, and 97.1% at a cutoff of 1.470, respectively. After 48 hours of cisplatin treatment, compared with the NC group and nontransfected (non-T) group, the mimic group had decreased rates of cell inhibition and apoptosis, but the inhibitor group had increased rates (all P<0.05). The expression levels of caspase3 protein were increased in the mimic group and decreased in the inhibitor group. Cell survival rates in the mimic group at different time points after cisplatin treatment were significantly higher than the corresponding rates in the NC and non-T groups, whereas the cell survival rates in the inhibitor group were significantly lower than the rates in the NC and non-T groups (all P<0.05). The concentration and action time of cisplatin were negatively associated with the cell survival rate in each group (all P<0.05).

CONCLUSION

Cisplatin-based chemosensitivity of PGBC increased as expression of miR-1207-5p in peripheral blood declined. Thus, miR-1207-5p appears to be a promising and novel chemosensitizer for the treatment of PGBC.

The inflammatory inception of gallbladder cancer

Gallbladder cancer is a lethal disease with notable geographical variations worldwide and a predilection towards women. Its main risk factor is prolonged exposure to gallstones, although bacterial infections and other inflammatory conditions are also associated. The recurrent cycles of gallbladder epithelium damage and repair enable a chronic inflammatory environment that promotes progressive morphological impairment through a metaplasia-dysplasia-carcinoma, along with cumulative genome instability. Inactivation of TP53, which is mutated in over 50% of GBC cases, seems to be the earliest and one of the most important carcinogenic pathways involved. Increased cell turnover and oxidative stress promote early alteration of TP53, cell cycle deregulation, apoptosis and replicative senescence. In this review, we will discuss evidence for the role of inflammation in gallbladder carcinogenesis obtained through epidemiological studies, genome-wide association studies, experimental carcinogenesis, morphogenetic studies and comparative studies with other inflammation-driven malignancies. The evidence strongly supports chronic, unresolved inflammation as the main carcinogenic mechanism of gallbladder cancer, regardless of the initial etiologic trigger. Given this central role of inflammation, evaluation of the potential for GBC prevention removing causes of inflammation or using anti-inflammatory drugs in high-risk populations may be warranted.

Well-differentiated endocrine carcinoma originating from the bile duct in association with a congenital choledochal cyst

We encountered a rare case of a well-differentiated endocrine carcinoma originating from the bile duct in association with a congenital choledochal cyst (CCC). The patient is a 28-year-old woman referred to our clinic for pruritus. Laboratory data showed mild elevation of serum hepatobiliary enzymes. Computed tomography and magnetic resonance imaging demonstrated pancreatobiliary maljunction and a Todani type IV-A CCC from the inferior bile duct to the bilateral intrahepatic bile ducts. A solid tumor was detected in the middle portion of the common bile duct. Pancreatoduodenectomy and total extrahepatic bile duct resection was performed. Based on pathologic and immunohistochemical examinations, a diagnosis of well-differentiated endocrine carcinoma was made according to the World Health Organization criteria. To our knowledge, this is the third report of a neuroendocrine tumor originating from the bile duct in association with a CCC.

A genetic model for gallbladder carcinogenesis and its dissemination

Gallbladder cancer, although regarded as the most common malignancy of the biliary tract, continues to be associated with a dismal overall survival even in the present day. While complete surgical removal of the tumour offers a good chance of cure, only a fraction of the patients are amenable to curative surgery owing to their delayed presentation. Moreover, the current contribution of adjuvant therapies towards prolonging survival is marginal, at best. Thus, understanding the biology of the disease will not only enable a better appreciation of the pathways of progression but also facilitate the development of an accurate genetic model for gallbladder carcinogenesis and dissemination. This review provides an updated, evidence-based model of the pathways of carcinogenesis in gallbladder cancer and its dissemination. The model proposed could serve as the scaffolding for elucidation of the molecular mechanisms involved in gallbladder carcinogenesis. A better understanding of the pathways involved in gallbladder tumorigenesis will serve to identify patients at risk for the cancer (and who thus could be offered prophylactic cholecystectomy) as well as aid oncologists in planning the most suitable treatment for a particular patient, thereby setting us on the vanguard of transforming the current treatment paradigm for gallbladder cancer.

Clinical features of pancreaticobiliary maljunction: update analysis of 2nd Japan-nationwide survey

INTRODUCTION

Pancreaticobiliary maljunction (PBM) is a congenital anomaly, which can be defined as a union of the pancreatic and biliary ducts located outside off the duodenal wall. We herein investigate clinical features of PBM including as the 2nd report of a Japanese nationwide survey.

PATIENTS AND METHODS

During a period of 18 years (from 1990 to 2007), 2,561 patients with PBM were registered at 141 medical institutions in Japan. Among them, eligible patients (n = 2,529) were divided into two groups: adult (n = 1,511) and pediatric patients (n = 1,018). Comparisons of clinical features including associated biliary cancers were performed according to the biliary dilatation (BD), age factor, and time era.

RESULTS

Only one case in pediatric patients with BD combined with a bile duct cancer (0.1 %). In adult patients, the bile duct cancer and the gallbladder cancer was seen in 6.9 and 13.4 % patients with BD and in 3.1 and 37.4 % patients without BD, respectively. In adult patients with BD, the occurrence rates of biliary cancers were increased in latter period (00'-07') compared with former period (90'-99'). The ratio of biliary cancer localization was changed between former and latter period, and the bile duct cancer was increased in latter period (from 5.5 to 9.3 %).

CONCLUSIONS

The largest series of PBM were evaluated to clarify the clinical features including the associated biliary cancer in this Japan-nationwide survey. This report could be widely used in the future as a reference data for diagnosis and treatment of PBM.

Pancreaticobiliary maljunction is associated with common bile duct carcinoma: a meta-analysis

Objective. Pancreaticobiliary maljunction (PBM) has been reported to be associated with an increased risk of gallbladder carcinoma. However, the relationship between PBM and common bile duct carcinoma (CBDC) remains unclear. We aimed to conduct a meta-analysis to determine the available evidence on the association between PBM and CBDC. Methods. The pooled odds ratio (OR) and standard mean differences (SMD) with 95% confidence interval (95% CI) were used to estimate the effects. Results. A total of eight case-control studies and two cohort studies were identified. The incidence of PBM was higher in CBDC patients than in controls (OR = 1.45; 95% CI, 1.19–1.76). Compared with patients without PBM, CBDC patients with PBM were younger at the diagnosis age (SMD = −0.46; 95% CI, −0.64 to −0.28). A difference in the incidence of associated CDC was found between CBDC patients with or without PBM (OR = 2.14; 95% CI, 1.60–2.87). Conclusions. Compared with benign biliary tract diseases, the incidence of PBM was higher in CBDC patients, especially in relatively young patients. We also found that the incidence of CDC was higher in CBDC patients with PBM. These findings showed positive association between PBM and CBDC, which may help in identifying high-risk individuals.

Early diagnosis of gallbladder carcinoma: an algorithm approach

Gall bladder carcinoma is the most common biliary tract cancer. Delayed presentation and early spread of tumor make it one of the lethal tumors with poor prognosis. Considering that simple cholecystectomy for T1 disease could offer a potential cure, it is increasingly needed to identify it at early stages. Identification of high-risk cases and offering prophylactic cholecystectomy can decrease the incidence of gallbladder carcinoma. With advances in diagnostic tools like contrast-enhanced endoscopic ultrasound, elastography, multidetctor CT, MRI, and PET scan, we can potentially diagnose gallbladder carcinoma at early stages. This paper reviews the various diagnostic modalities available and an algorithmic approach to early diagnosis of gallbladder carcinoma.

Helicobacter bilis colonization of the biliary system in patients with pancreaticobiliary maljunction

BACKGROUND

Helicobacter bilis is considered to be a causative factor in the pathogenesis of biliary cancer. This study investigated the prevalence of H. bilis colonization of the biliary system of patients with pancreaticobiliary maljunction (PBM).

METHODS

Bile juice and biliary tissue samples were collected from 17 patients with PBM and 27 controls who had benign biliary disease without PBM. DNA extracted from each biliary sample was subjected to polymerase chain reaction (PCR) analysis for H. bilis and Helicobacter pylori.

RESULTS

PCR assays revealed that 12 of the 17 patients with PBM were positive for H. bilis DNA, compared with eight of 27 patients without PBM (P = 0.009). Among patients with PBM, H. bilis DNA was identified in six of eight children, including a 2-month-old infant, and in six of nine adults. The high prevalence of H. bilis DNA in the biliary system of patients with PBM was independent of age, sex, common bile duct dilatation, configuration of the pancreatic and bile ducts, and amylase activity in bile.

CONCLUSION

H. bilis colonization of the biliary system is extremely common in patients with PBM. This may point to a role in the pathogenesis of biliary cancer.

Carcinogenesis and chemoprevention of biliary tract cancer in pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is a high risk factor for biliary tract cancer. In PBM, since the pancreatic duct and bile duct converge outside the duodenal wall beyond the influence of the sphincter of Oddi, pancreatic juice and bile are constantly mixed, producing a variety of harmful substances. Because of this, the biliary mucosa is repeatedly damaged and repaired, which causes an acceleration of cell proliferative activity and multiple gene mutations. Histological changes such as hyperplasia, metaplasia, and dysplasia ultimately result in a high incidence of carcinogenesis. In a nationwide survey by the Japanese Study Group on PBM, coexisting biliary tract cancer was detected in 278 of the 1627 registered cases of PBM (17.1%). Of these cases, in those with dilatation of the extrahepatic bile duct, cancer was often detected not only in the gallbladder but also in the bile ducts. More than 90% of cancer cases without dilatation of the extrahepatic bile duct develop in the gallbladder. Standard treatment for PBM is a cholecystectomy and resection of the extrahepatic bile duct. However, cholecystectomy alone is performed at nearly half of institutions in Japan. Conversely, reports of carcinogenesis in the remnant bile duct or pancreas after diversion surgery are steadily increasing. One of the causes for this is believed to be an accumulation of gene mutations which were present before surgery. Anticancer drugs are ineffective in preventing such carcinogenesis following surgery, thus the postoperative administration of chemopreventive agents may be necessary.

Diagnosis and clinical implications of pancreatobiliary reflux

The sphincter of Oddi is located at the distal end of the pancreatic and bile ducts and regulates the outflow of bile and pancreatic juice. A common channel can be so long that the junction of the pancreatic and bile ducts is located outside of the duodenal wall, as occurs in pancreaticobiliary maljunction (PBM); in such cases, sphincter action does not functionally affect the junction. As the hydropressure within the pancreatic duct is usually greater than in the bile duct, pancreatic juice frequently refluxes into the biliary duct (pancreatobiliary reflux) in PBM, resulting in carcinogenetic conditions in the biliary tract. Pancreatobiliary reflux can be diagnosed from elevated amylase level in the bile, secretin-stimulated dynamic magnetic resonance cholangiopancreatography, and pancreatography via the minor duodenal papilla. Recently, it has become obvious that pancreatobiliary reflux can occur in individuals without PBM. Pancreatobiliary reflux might be related to biliary carcinogenesis even in some individuals without PBM. Since few systemic studies exist with respect to clinical relevance and implications of the pancreatobiliary reflux in individuals with normal pancreaticobiliary junction, further prospective clinical studies including appropriate management should be performed.

Pancreaticobiliary maljunction and carcinogenesis to biliary and pancreatic malignancy

BACKGROUND

It is widely accepted that congenital choledochal cyst is associated with pancreaticobiliary maljunction (PBM). But, PBM is an independent disease entity from choledochal cyst. PBM is synonymous with "abnormal junction of the pancreaticobiliary ductal system", "anomalous arrangement of pancreaticobiliary ducts", "anomalous union of bilio-pancreatic ducts", etc. Cases with PBM not associated with biliary duct dilatation are often found, and these cases are frequently complicated gallbladder cancer. The Japanese Study Group of Pancreaticobiliary Maljunction was started in 1983, and defined diagnostic criteria and nationwide registration system of PBM cases was started. PBM is defined as a union of the pancreatic and biliary ducts which is located outside the duodenal wall. Bile and pancreatic juice reflux and regurgitate mutually.

BILIARY CARCINOGENESIS

The most bothersome problem is biliary carcinogenesis. Gallbladder cancers arise in 14.8% and bile duct cancers arise in 4.9%. The incidence of the gallbladder carcinoma of PBM without bile duct dilatation is 36.1%. Many investigators have tried to clarify the carcinogenic process, from various aspects. The biliary epithelia are injured by harmful substances, and in the course of repair, multiple alterations of oncogenes and tumor suppressor genes are followed, and they lead to carcinoma through multistage interaction. In the biliary epithelia of PBM, incidence and degree of hyperplasia are characteristic. K-ras gene mutations are observed in the cancerous as well as noncancerous lesions of biliary tract of PBM patients. Mutations of p53 gene and overexpression of p53 protein are also found in the cancerous and noncancerous lesions. These changes are called "hyperplasia-carcinoma sequence".

TREATMENT

Total excision of the extrahepatic bile duct with gallbladder followed by hepaticojejunostomy, Roux-en-Y, or end-to-side hepaticoduodenostomy are treatment of choice, even for cases with not dilated bile duct, because the incidence of cancer in the nondilated bile duct is not negligible, and genetic changes are seen in a nondilated bile duct.

Secretin-stimulating MRCP in patients with pancreatobiliary maljunction and occult pancreatobiliary reflux: direct demonstration of pancreatobiliary reflux

We propose the hypothesis that the enlargement of the common bile duct (CBD) or gallbladder (GB) that is occasionally demonstrated on magnetic resonance cholangiopancreatography (MRCP) after secretin stimulation is caused by pancreatobiliary reflux. Recently, occult pancreatobiliary reflux (OPR) has been demonstrated in patients without morphological pancreatobiliary maljunction (MPBM). The aim of this study was to evaluate the efficacy of secretin-stimulating MRCP (SMRCP) in the diagnosis of pancreatobiliary reflux. The study included 14 patients with MPBM and 32 patients with a normal pancreatobiliary junction. OPR was evaluated by bile collection and diagnosed in seven of the 32 patients. All the patients underwent SMRCP; the related findings were considered positive when enlargement of the CBD or GB was observed. Positive findings on SMRCP were observed in all MPBM patients. In the patients with normal pancreatobiliary junction, there was significant difference between the mean amylase levels in the patients with positive and negative SMRCP findings (mean, 4,755.7 and 29.7 IU/l). The sensitivity and specificity of SMRCP for diagnosing OPR was 85.7% and 68.0%, respectively. SMRCP provides a non invasive method for excluding PBR and can identify patients who could benefit from bile duct sampling to diagnose OPR.

Expression of GalNAc-T3 and its relationships with clinicopathological factors in 61 extrahepatic bile duct carcinomas analyzed using stepwise sections - special reference to its association with lymph node metastases-

Extrahepatic bile duct carcinomas (EBDCs) still result in an unfavorable prognostic outcome, and little is known about their biological aggressiveness. Recently, UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyl transferase-3 (GalNAc-T3) was reported to be associated with differentiation and malignant potential of human carcinomas. Here, we investigated 61 EBDCs for their detailed clinicopathological features and GalNAc-T3 expression by immunohistochemistry, and then evaluated the relationships between the clinicopathological features and GalNAc-T3 expression patterns. Most of the EBDCs were massively invasive tumors with frequent vascular or perineural invasion and lymph node metastases. GalNAc-T3 expression was detected in all 61 EBDCs, and the expression patterns could be classified into granular and diffuse types. All four noninvasive or minimally invasive EBDCs were the granular type. Among the 58 minimally or massively invasive EBDCs, the GalNAc-T3 expression pattern at the luminal surface was the granular type in 38 cases (66%) and diffuse type in 20 cases (34%), while the expression pattern at the invasive front was the granular type in 26 cases (45%) and diffuse type in 32 cases (55%). Among the 38 cases with granular-type expression at the luminal surface, 26 cases (68%) remained the granular type and 12 cases (32%) became the diffuse type at the invasive front. All 20 cases with diffuse-type expression at the luminal surface remained the diffuse type at the invasive front. Diffuse-type GalNAc-T3 expression at the invasive front was significantly associated with lymph node metastasis (P<0.05). There were no significant correlations between the GalNAc-T3 expression patterns and other clinicopathological factors, including tumor differentiation, depth of invasion or overall survival. In conclusion, EBDCs alter their GalNAc-T3 expression pattern during tumor growth, and the difference in the GalNAc-T3 expression pattern may be associated with lymph node metastasis. Clinically, preoperative evaluation of GalNAc-T3 expression is considered to be useful for decisions regarding operative procedures.

Gallbladder carcinoma associated with pancreatobiliary reflux

AIM: To detect the patients with and without pan-creaticobiliary maljunction who had pancreatobiliary reflux with extremely high biliary amylase levels.

METHODS: Ninety-six patients, who had diffuse thickness (> 3 mm) of the gallbladder wall and were suspected of having a pancreaticobiliary maljunction on ultrasonography, were prospectively subjected to endoscopic retrograde cholangiopancreatography, and bile in the common bile duct was sampled. Among them, patients, who had extremely high biliary amylase levels (>10 000 IU/L), underwent cholecystectomy, and the clinicopathological findings of those patients with and without pancreaticobiliary maljunction were examined.

RESULTS: Seventeen patients had biliary amylase levels in the common bile duct above 10 000 IU/L, including 11 with pancreaticobiliary maljunction and 6 without pancreaticobiliary maljunction. The occurrence of gallbladder carcinoma was 45.5% (5/11) in patients with pancreaticobiliary maljunction, and 50% (3/6) in those without pancreaticobiliary maljunction.

CONCLUSION: Pancreatobiliary reflux with extremely high biliary amylase levels and associated gallbladder carcinoma could be identified in patients with and without pancreaticobiliary maljunction, and those patients might be detected by ultrasonography and bile sampling.

Inhibitory effect of meloxicam, a cyclooxygenase-2 inhibitor, on N-nitrosobis (2-oxopropyl) amine induced biliary carcinogenesis in Syrian hamsters

Pancreaticobiliary maljunction (PBM) is a high risk factor in biliary tract carcinoma. The chemopreventive action of a cyclooxygenase (COX)-2 inhibitor (meloxicam) on N-nitrosobis (2-oxopropyl) amine (BOP)-induced gallbladder cancer in hamster PBM models was investigated. In 7-week-old female Syrian golden hamsters, the extrahepatic bile duct at the distal end of the common duct was ligated and cholecystoduodenostomy was performed (group I). In group II, the same surgery was performed and from week 4 after surgery, 10 mg/kg of BOP was injected subcutaneously once a week with a 1-week interval. In group III, in addition to the measures employed in group II, 5 mg/kg/day of meloxicam was administered once a day, every weekday. Pathological findings in the gallbladder in week 20 after surgery were as follows. In group I, proper epithelium (PE) was predominant and there was no cancer. In group II, PE was predominant, but there was also hyperplasia and atypical epithelium (AE) recognized in 8 of 11 cases (72.7%); the area of AE was more extensive than that in group I. Carcinoma in situ (CIS) was recognized in 4 of 11 cases (36.4%) in group II. Group III showed the same pathological findings as group I. However, compared with group II, the incidence of AE decreased to 27.3% and no cancerous lesion was observed. In week 20 after surgery, the proliferative cell nuclear antigen labeling index in group III was statistically significantly lower than in group II (P = 0.045). No statistically significant differences were noted among the groups in terms of apoptosis labeling index in week 20 after surgery. In conclusion, it was confirmed that meloxicam suppresses carcinogenesis in hamster PBM models and its mechanism may be based on the suppression of cell growth.

Gallbladder cancer: lessons from a rare tumour

Gallbladder cancer is a relatively rare form of malignancy about which our knowledge is scant. However, a unique combination of predisposing factors - including genetic predisposition, geographic distribution, female gender bias, chronic inflammation and congenital developmental abnormalities - makes this type of cancer unique and offers potential for understanding cancer pathogenesis in general. An understanding of how these risk factors contribute to the molecular basis of the disease is essential for understanding the origins of this unusual cancer.

Progression of gene hypermethylation in gallstone disease leading to gallbladder cancer

BACKGROUND

Aberrant methylation of tumor-suppressor genes is associated with a loss of gene function that can afford selective growth advantages to sporadic neoplastic cells arising during gallbladder inflammation.

METHODS

Fifty-four gallbladder neoplasms were selected from tumor banks in the United States and Chile. Each of the neoplasms was subjected to methylation-specific polymerase chain reaction to detect promoter methylation associated with six candidate tumor-suppressor genes (p16, APC, methylguanine methyltransferase, hMLH1, retinoic acid receptor beta-2, and p73) implicated in multiple human cancer types.

RESULTS

Aberrant methylation of any of the six candidate tumor-suppressor genes was detected in 72% of the gallbladder neoplasms, 28% of the cases of chronic cholecystitis, and in only 1 of the 15 normal gallbladder controls. The four most commonly methylated genes in the gallbladder cancers were p16 (56%), p73 (28%), APC (27%), and hMLH1 (14%). Significant differences in gene methylation were discovered between US gallbladder cancers and those from Chile, where gallbladder cancer is one of the leading causes of cancer-related deaths. APC methylation was present in 42% of the US cases but in only 14% of the Chilean tumors (P =.028). p73 methylation was common among the Chilean cancers (40%) compared with those from the United States (13%; P =.034).

CONCLUSIONS

The acquisition of hypermethylation at multiple tumor-suppressor gene-promoter sites may contribute to tumor formation and progression within the chronically inflamed gallbladder. The apparent differences in methylation patterns among the Chilean and US gallbladder cases may indicate a unique biology associated with this cancer in different parts of the world.

Pancreaticobiliary maljunction: pathophysiological and clinical aspects and the impact on biliary carcinogenesis

BACKGROUND

Pancreaticobiliary maljunction (PBM) is frequently associated with congenital choledochal cyst (CCBD), but differs in embryonic cause and clinical features. It is thought to develop as a misarrangement of the embryonic connections in the pancreaticobiliary ductal system, with the terminal bile duct joined to one of the ducts of the ventral pancreas. Clinical aspects are intermittent abdominal pain, relapsing acute pancreatitis, jaundice, cholangitis, and gallbladder cancer. In patients with PBM and CCBD, primary bile duct stones, acute cholangitis, and bile duct cancer are considered to result from cholestasis, regurgitation of pancreatic juice, and reciprocal reflux of bile and pancreatic juice. The mixture of bile and pancreatic juice due to recipocal reflex very likely plays an important role in biliary carcinogenesis.

PATIENTS AND METHODS

We reviewed the pathophysiological and clinical aspects and biliary carcinogenesis in 250 PBM patients (169 with benign hepatobiliary and pancreatic disease, 81 with malignancy).

RESULTS

PBM patients show elevated cellular proliferation activity in the gallbladder epithelia. A number of oncogenes and tumor suppressor genes have been identified and implicated in carcinogenesis, particularly the K- ras oncogene and the p53 suppressor gene. Some K- ras mutations do not appear essential for hyperplasia but may be an early event in carcinogenesis. The p53 mutations are involved in carcinogenesis in the biliary epithelium in PBM patients.

Immunohistochemical detection of 8-hydroxy-2'-deoxyguanosine in gallbladder epithelium of patients with pancreaticobiliary maljunction

OBJECTIVES

Pancreaticobiliary maljunction, an anomalous union of the pancreatic duct with the common bile duct, is a risk factor for biliary carcinoma. We hypothesized that, in patients with pancreaticobiliary maljunction, persistent regurgitation of pancreatic juice into the biliary tract induces oxidative DNA damage. We assessed the expression of an oxidative DNA base-modified product, 8-hydroxy-2'-deoxyguanosine, in gallbladder epithelium.

DESIGN

Eleven noncancerous gallbladders from patients with pancreaticobiliary maljunction, 12 gallbladder carcinomas from patients without pancreaticobiliary maljunction and 14 noncancerous gallbladders from patients without pancreaticobiliary maljunction (control) were studied.

METHODS

Immunohistochemistry was performed for 4-hydroxy-2-nonenal-modified protein (as a marker for lipid peroxidation), 8-hydroxy-2'-deoxyguanosine and p53 gene product.

RESULTS

Stronger cytoplasmic staining of 4-hydroxy-2-nonenal-modified protein was observed in the gallbladder epithelium from patients with pancreaticobiliary maljunction than in epithelium from gallbladder cancer patients or from control subjects with normal gallbladders. Clear, strong nuclear staining of 8-hydroxy-2'-deoxyguanosine was observed in the gallbladder epithelial cells from patients with pancreaticobiliary maljunction. Densitometric quantitation revealed significantly higher expression of 8-hydroxy-2'-deoxyguanosine in gallbladder epithelial cells from patients with pancreaticobiliary maljunction (index 27.3 +/- 3.1) than in cells from patients with gallbladder carcinoma (11.4 +/- 1.5; P < 0.05) or from control subjects with normal gallbladder (6.4 +/- 1.0; P < 0.05). Positivity of p53 was 27% in gallbladder epithelium associated with pancreaticobiliary maljunction, 75% in gallbladder carcinoma epithelium and 0% in control epithelium.

CONCLUSIONS

These results suggest that reactive oxygen species are produced in the gallbladder of patients with pancreaticobiliary maljunction and that oxidative DNA injury is related to carcinogenesis in these patients.

Low frequency of p53 and ras mutations in bile of patients with hepato-biliary disease: a prospective study in more than 100 patients

The diagnosis of biliary disease, namely malignant disorders, is frequently hampered by the inconclusive cytology. We investigated prospectively the frequency of molecular changes in p53 and ras compared with cytology in patients with primary or secondary hepato-biliary disease. We investigated 118 consecutive patients, aged 24-89 with the following clinical diagnoses: choledocho/cholecystolithiasis (28), cholangiocellular carcinoma (21), gall bladder tumor (8), liver metastasis (3), autoimmune disease (8), chronic pancreatitis (16), pancreatic carcinoma (11), papillary disease (4), hepatic cirrhosis (6), cholangitis (2), anomalies (2), and normal (9). Bile was aspirated during routine endoscopic retrograde cholangio pancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC). DNA was prepared freshly from a native aliquot. p53 mutations were detected by polymerase chain reaction (PCR) for exons 5 through 8 followed by TGGE. PCR for ras mutations was performed as RFLP-PCR with sequencing. In four cases, mutations in p53 could be found in exons 6 and 7. Twenty-two samples showed ras mutations; ras mutations were found in choledocholithiasis (4/28), bile duct (5/21), gall bladder (3/8) and pancreatic (1/11) carcinoma, liver metastasis (3/3), ulcerative colitis (2/3), PSC (1/2), and chronic pancreatitis (1/16). Cytology was clearly positive in seven cases, suspicious in three other, inconclusive in six, and negative in the rest. The molecular analysis resulted in a sensitivity of 33% and specificity of 87%, respectively, for the diagnosis of a malignant condition. PCR for p53 and ras mutations may aid the diagnosis of primary and secondary (metastatic) hepatobiliary disease if a malignant condition of the bile ducts and the liver is suspected and cytology is inconclusive or negative. However, the incidence of p53 and ras mutations in bile seems less frequent than in other malignant conditions of the gastrointestinal tract and the pancreas and lower than in tissue, leaving a poor sensitivity and specificity. Nevertheless, the presence of a p53 and/or ras mutation per se supports a clinical suspicion of malignancy, even when the conventional cytology is negative or inconclusive.

Gene mutations of K-ras in gallbladder mucosae and gallbladder carcinoma with an anomalous junction of the pancreaticobiliary duct

OBJECTIVE

In this study, we examined the mutational spectrum of K-ras in cases of gallbladder and gallbladder carcinoma with an anomalous junction of the pancreaticobiliary duct (AJPBD).

METHODS

We examined 35 gallbladders with AJPBD (20 with hyperplasia, 15 with carcinoma) and 38 gallbladders without AJPBD (four normal gallbladders, four with hyperplasia, six with adenoma, 24 with carcinoma). Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing were performed to detect mutations in codon 12 or 13 of K-ras.

RESULTS

In the cases with AJPBD, the prevalences of K-ras mutation were 15% (3/20) in hyperplasia, 60% (6/10) in stage I carcinoma, and 100% (5/5) in stage II-IV carcinoma. In the cases without AJPBD, the prevalences of K-ras mutation were 0% (0/4) in normal gallbladder, 0% (0/4) in hyperplasia, 17% (1/6) in adenoma, 7% (1/16) in stage I carcinoma, and 38% (3/8) in stage II-IV carcinoma. Prevalences of K-ras mutation in hyperplasia and carcinoma with AJPBD were greater than those without AJPBD (p < 0.05). The point mutation of GGT to GAT in codon 12 was frequently observed in the cases with AJPBD.

CONCLUSION

These results suggest that the specific K-ras mutation in codon 12 (GGT to GAT) may contribute to the early stage of carcinogenesis in the gallbladder with AJPBD.

Cellular activity in the gallbladder of children with anomalous arrangement of the pancreaticobiliary duct

BACKGROUND/PURPOSE

Anomalous arrangement of the pancreaticobiliary duct (AAPBD) is closely related to congenital biliary dilatation and frequently associated with biliary tract malignancy. To examine the mechanism of biliary tract carcinogenesis in patients with AAPBD, we investigated histologically the early changes in cell proliferative kinetics of the gallbladder mucosa of children with AAPBD.

METHODS

Twenty-three specimens of gallbladder were obtained from 23 children with AAPBD, and six control specimens were obtained from pediatric patients. All specimens were fixed routinely and paraffin embedded and examined histologically with H&E staining and immunohistochemically with monoclonal antibody Ki-67(MIB-1), which reacts with a human nuclear antigen associated with cell proliferation. Ki-67 labeling index (Ki-67 LI) was obtained by counting the numbers of Ki-67-positive cells per 1,000 gallbladder epithelial cells.

RESULTS

Significant differences in Ki-67 LI were noted between children with and without AAPBD. Furthermore, Ki-67 LI and the incidence of epithelial hyperplasia of gallbladder were significantly higher in children with AAPBD in whom the major pancreatic duct joined the common bile duct (P-C type) than in those in whom the common bile duct joined the major pancreatic duct (C-P type).

CONCLUSIONS

Cellular proliferative activity was increased in children with AAPBD, especially those with the P-C-type anomaly. These results suggest that the early mucosal changes of the gallbladder occurred in early childhood of patients with AAPBD and might be associated with gallbladder cancer. Early diagnosis and early surgical division of the biliary tract and pancreatic duct is recommended for children with AAPBD.

Mutations of K-ras but not p53 genes in biliary duct and pancreatic duct carcinomas induced in hamsters by cholecystoduodenostomy with dissection of the common duct followed by N-nitrosobis(2-oxopropyl)amine

An experimental model for the induction of extrahepatic biliary duct carcinomas in hamsters given cholecystoduodenostomy with dissection of the extrahepatic duct at the distal end of the common duct (CDDB) followed by N-nitrosobis(2-oxopropyl)amine (BOP) has been reported [Tajima et al. (1994) Jpn. J. Cancer Res., 85, 780-788]. The CDDB procedure greatly accelerates cell turnover in the biliary epithelium. In the present experiment, mutations of K-ras and p53 genes in the induced lesions were investigated by the reverse transcriptase-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) method followed by direct sequencing. Mutations of K-ras, involving a G to A transition in second position of codon 12 of K-ras exon 1, were detected in six out of eight (75%) extrahepatic bile duct carcinomas and six out of eleven (54.5%) pancreatic duct carcinomas. However, no mutations of p53 were observed in either tumor type. The results indicate an association between anomalous pancreaticobiliary junction and development of biliary carcinomas that may be pertinent to the human situation, and indicate that conditions of the model predispose to mutations occurring in K-ras but not p53.