Randomized clinical trial of adjuvant gemcitabine chemotherapy versus observation in resected bile duct cancer.

BACKGROUND: Although some retrospective studies have suggested the value of adjuvant therapy, no recommended standard exists in bile duct cancer. The aim of this study was to test the hypothesis that adjuvant gemcitabine chemotherapy would improve survival probability in resected bile duct cancer. METHODS: This was a randomized phase III trial. Patients with resected bile duct cancer were assigned randomly to gemcitabine and observation groups, which were balanced with respect to lymph node status, residual tumour status and tumour location. Gemcitabine was given intravenously at a dose of 1000 mg/m2 , administered on days 1, 8 and 15 every 4 weeks for six cycles. The primary endpoint was overall survival, and secondary endpoints were relapse-free survival, subgroup analysis and toxicity. RESULTS: Some 225 patients were included (117 gemcitabine, 108 observation). Baseline characteristics were well balanced between the gemcitabine and observation groups. There were no significant differences in overall survival (median 62·3 versus 63·8 months respectively; hazard ratio 1·01, 95 per cent c.i. 0·70 to 1·45; P = 0·964) and relapse-free survival (median 36·0 versus 39·9 months; hazard ratio 0·93, 0·66 to 1·32; P = 0·693). There were no survival differences between the two groups in subsets stratified by lymph node status and margin status. Although haematological toxicity occurred frequently in the gemcitabine group, most toxicities were transient, and grade 3/4 non-haematological toxicity was rare. CONCLUSION: The survival probability in patients with resected bile duct cancer was not significantly different between the gemcitabine adjuvant chemotherapy group and the observation group. Registration number: UMIN 000000820 (http://www.umin.ac.jp/).

Percutaneous transhepatic biliary drainage catheter tract recurrence in cholangiocarcinoma.

BACKGROUND: The aim of the study was to clarify the incidence, risk factors and treatment of percutaneous transhepatic biliary drainage (PTBD) catheter tract recurrence in patients with resected cholangiocarcinoma. METHODS: The medical records of 445 patients with perihilar and distal cholangiocarcinoma who underwent resection following PTBD were reviewed retrospectively. RESULTS: PTBD catheter tract recurrence was detected in 23 patients (5.2 per cent). The mean(s.d.) interval between surgery and onset of the recurrence was 14.4(13.8) months. On multivariable analysis, duration of PTBD (60 days or more), multiple PTBD catheters and macroscopic papillary tumour type were identified as independent risk factors. In four patients with synchronous metastasis, the PTBD sinus tract was resected simultaneously, at the time of initial surgery. Of 19 patients with metachronous metastasis, 15 underwent surgical resection of the metastasis. Survival of the 23 patients with PTBD catheter tract recurrence was poorer than that of the 422 patients without recurrence (median 22.8 versus 27.3 months; P = 0.095). Even after surgical resection of PTBD catheter tract recurrence, survival was poor. CONCLUSION: PTBD catheter tract recurrence is not unusual. The prognosis for these patients is generally poor, even after resection. To prevent this troublesome complication, endoscopic biliary drainage is first recommended when drainage is indicated.

Gemcitabine alone or in combination with cisplatin in patients with biliary tract cancer: a comparative multicentre study in Japan.

BACKGROUND: A British randomised study of gemcitabine plus cisplatin (GC) combination showed promising results in biliary tract cancer (BTC) patients. In our study, we evaluated the efficacy and safety of this combination compared with gemcitabine alone (G) in Japanese BTC patients. METHODS: Overall, 84 advanced BTC patients were randomised to either cisplatin 25 mg m(-2) plus gemcitabine 1000 mg m(-2) on days 1, 8 of a 21-day cycle (GC-arm), or single-agent gemcitabine 1000 mg m(-2) on days 1, 8 and 15 of a 28-day cycle (G-arm). Treatments were repeated for at least 12 weeks until disease progression or unacceptable toxicity occurred, up to a maximum of 48 weeks. RESULTS: A total of 83 patients were included in the analysis. For the GC and G-arms, respectively, the 1-year survival rate was 39.0 vs 31.0%, median survival time 11.2 vs 7.7 months, median progression-free survival time 5.8 vs 3.7 months and overall response rate 19.5 vs 11.9%. The most common grade 3 or 4 toxicities (GC-arm/G-arm) were neutropenia (56.1%/38.1%), thrombocytopenia (39.0%/7.1%), leukopenia (29.3%/19.0%), haemoglobin decrease (36.6%/16.7%) and gamma-GTP increase (29.3%/35.7%). CONCLUSIONS: Gemcitabine plus cisplatin combination therapy was found to be effective and well tolerated, suggesting that it could also be a standard regimen for Japanese patients.

The concept of perihilar cholangiocarcinoma is valid.

BACKGROUND: The term perihilar cholangiocarcinoma has been used for all tumours involving or requiring resection of the hepatic confluence. However, it does not distinguish between intrahepatic and extrahepatic hilar tumours, and has no clinicopathological basis. This retrospective study examined whether the concept of perihilar cholangiocarcinoma is valid clinically. METHODS: Some 250 patients with perihilar cholangiocarcinoma were divided into extrahepatic (EHC, 167 patients) and intrahepatic (IHC, 83) groups based on tumour location. Clinicopathological data were compared between these groups. RESULTS: Liver, portal vein, venous and lymphatic invasion, and nodal metastasis were more common in IHCs than EHCs, whereas histological grade and incidence of perineural invasion were similar. IHCs were more advanced at the time of surgery; stage III or IV disease was found in 37.7 per cent of EHCs and 59 per cent of IHCs. Survival was marginally better for patients with EHCs than for those with IHCs (29.3 versus 20 per cent at 5 years; P = 0.057), but survival rates were similar for each tumour stage in the American Joint Committee on Cancer classification. CONCLUSION: Combining EHC and IHC under the term perihilar cholangiocarcinoma is valid, as these tumours have comparable biological behaviour, with similar clinical management depending on stage and invasion.

Radical surgery of left-sided klatskin tumors.

Left-sided cholangiocarcinoma includes hilar cholangiocarcinoma (HC), predominantly involving the left hepatic duct, and intrahepatic cholangiocarcinoma (ICC) in the left liver. Left hepatectomy, or left hepatic trisectionectomy, is indicated as radical surgery of left-sided HC or ICC with or without hilar bile duct invasion. Left lateral sectionectomy, or left medial sectionectomy, is performed for the small mass-forming type ICC. Left hepatic trisectionectomy is indicated for left-sided HC with further cancer progress along the right anterior sectional duct or left-sided ICC involving the right anterior section over the middle hepatic vein and/or the right anterior pedicle. Combined caudate lobe and extrahepatic bile duct resection are mandatory in cases of HC or ICC involving the hepatic confluence. Preoperative biliary drainage should be performed not only for jaundiced patients but also for non-icteric patients with right-sided biliary dilatation of the future remnant liver. Preoperative left trisegment portal vein embolization after biliary drainage of the right posterior section should be carried out prior to left hepatic trisectionectomy. Left hepatectomy has been used as a radical and safer surgical procedure, but in European countries has still been associated with higher morbidity and about 10% operative mortality. Japanese surgeons have had no hospital deaths after carrying out left hepatic trisectionectomy done after preoperative biliary drainage followed by left trisegment portal vein embolization to increase safety and to prolong postoperative survival for patients with locally advanced left-sided cholangiocarcinoma.

Radical surgery: vascular and pancreatic resection for cholangiocarcinoma.

Recent progress in vascular surgical techniques has made it possible to combine liver and portal vein and/or hepatic artery (HA) or retrohepatic inferior vena cava (IVC) resection and reconstruction in cases of locally advanced cholangiocarcinoma. Reports of the success of this difficult surgery have been published. Aggressive Japanese surgeons have applied hepatopancreatoduodenectomy (HPD) not just in cases of advanced gallbladder cancer, but also in locally advanced cholangiocarcinoma with or without superficial spread. The above extended surgeries were associated with high postoperative morbidity and mortality, but recent progress in perioperative management and surgical techniques has improved the outcome of these types of surgery. Combined portal vein and liver resection provides R0 resection and contributes to longer survival in resected patients with locally advanced cholangiocarcinoma than in unresected patients. Portal vein invasion is a strong prognostic factor of cholangiocarcinoma and the actual number of 5-year survivors is limited. The number of clinical cases of liver resection combined with IVC or HA resection and reconstruction is still limited, and therefore the long-term survival benefit from these procedures has not been clarified. HPD carried high morbidity and mortality rates in the 1990s, but the outcome has been improving and an increasing number of 5-year survivors has been reported. Although the clinical value of the above extended surgeries has not been evaluated prospectively, with the increasing number of retrospective studies it has been concluded that combined liver and portal vein and/or HA or IVC resection or HPD could be indicated for selected patients with locally advanced cholangiocarcinoma.

Staging cholangiocarcinoma by cholangioscopy.

Peroral cholangioscopy (POCS) and percutaneous transhepatic cholangioscopy (PTCS) were first developed in the 1970s, and technical developments and clinical applications have taken place gradually ever since. POCS is used to diagnose small mucosal biliary lesions in non-icteric patients and early malignant changes in patients with persistent primary sclerosing cholangitis (PSC). Although PTCS is a more invasive diagnostic procedure than POCS, it has the advantage of precise diagnosis with mapping biopsy in defining the proximal and distal extension of superficially spreading cholangiocarcinoma (CCA) or mucin-producing CCA, which is predominantly found in papillary type CCA. POCS is significantly superior to ERCP in distinguishing between malignant and benign dominant bile duct stenoses in patients with PSC. The positive rate of PTCS biopsy for CCA is 96%, while morbidity and mortality of PTCS are 9% and 0%, respectively. Although magnetic resonance (MR) cholangiography may replace PTCS in determining the longitudinal spread of infiltrating type hilar CCA, the accuracy of MR cholangiography in papillary type hilar CCA is significantly lower than that of PTCS.

Preoperative biliary drainage before resection for cholangiocarcinoma (Pro).

Three types of preoperative biliary drainage (BD): percutaneous transhepatic (PTBD), endoscopic (EBD), and endoscopic nasobiliary (ENBD) can be indicated before resection of cholangiocarcinoma. However, three randomized controlled trials (RCTs) have revealed that preoperative PTBD does not improve perioperative results. Other RCTs have revealed that preoperative EBD for malignant obstructive jaundice has no demonstrable benefit and after EBD for hilar cholangiocarcinoma there are highly developed infectious complications. Most patients with distal cholangiocarcinoma undergo pancreatoduodenectomy (PD) without preoperative BD. However, no RCTs have been performed to clarify the safety of major hepatectomy without preoperative BD for cholestatic patients with hilar cholangiocarcinoma. Furthermore, preoperative intrahepatic segmental cholangitis is a prognostic factor in the outcome of major hepatectomy for biliary cancer. Preoperative BD has another purpose in the preoperative management of patients with hilar cholangiocarcinoma. Selective cholangiography via ENBD and/or PTBD catheters provides precise information about the complicated segmental anatomy of the intrahepatic bile ducts and extent of cancer along the separated segmental bile ducts, which contributes toward designing a type of resective procedure. RCTs in biliary cancer patients undergoing major hepatectomy have revealed that bile replacement during external biliary drainage and perioperative synbiotic treatment can prevent postoperative infectious complications. Although preoperative EBD increases the risk of cholangitis, major hepatectomy combined with preoperative biliary drainage, preferably PTBD and/or ENBD, followed by portal vein embolization has been established as a safer management strategy for perihilar cholangiocarcinoma.

New classification of cystic duct carcinoma.

BACKGROUND: Farrar's criteria for cystic duct carcinoma (histopathologic diagnosis of a carcinoma strictly limited to the cystic duct) are impractical especially when making a diagnosis of primary cystic duct carcinoma in its advanced stage. Therefore, in our previous study, we proposed a new definition of cystic duct carcinoma: a gallbladder tumor, the center of which is located in the cystic duct. In this study, we further propose a new classification for cystic duct carcinomas diagnosed by our definition. PATIENTS AND METHODS: This study included 44 surgical patients with cystic duct carcinoma diagnosed by our criteria. These patients were further classified into two groups: hepatic hilum type (HH, n = 29), in which the tumor mainly invades the hepatic hilum, and cystic confluence type (CC, n = 15), in which the tumor mainly involves the confluence of the cystic duct. The clinicopathologic features of these two groups were analyzed retrospectively. RESULTS: There was more papillary or well differentiated adenocarcinoma in the CC type lesions than in the HH type. The perineural and vascular invasion were more common in the HH type than in the CC type. The survival rate tends to be higher for patients with the CC type than for those with the HH type (p = 0.064). Moreover, we found a significantly different sex ratio between these two groups (female sex was predominant for the HH type, whereas male sex was predominant for the CC type). CONCLUSION: Our new classification showed two distinct types of advanced cystic duct carcinoma, which may help in understanding the clinical characteristics of the carcinoma originated in the cystic duct.

Apoptosis induction by antisense oligonucleotides against miR-17-5p and miR-20a in lung cancers overexpressing miR-17-92.

Amplification and overexpression of the miR-17-92 microRNAs (miRNA) cluster at 13q31.3 has recently reported, with pointers to functional involvement in the development of B-cell lymphomas and lung cancers. In the present study, we show that inhibition of miR-17-5p and miR-20a with antisense oligonucleotides (ONs) can induce apoptosis selectively in lung cancer cells overexpressing miR-17-92, suggesting the possibility of 'OncomiR addiction' to expression of these miRNAs in a subset of lung cancers. In marked contrast, antisense ONs against miR-18a and miR-19a did not exhibit such inhibitory effects, whereas inhibition of miR-92-1 resulted in only modest reduction of cell growth, showing significant distinctions among miRNAs of the miR-17-92 cluster in terms of their roles in cancer cell growth. During the course of this study, we also found that enforced expression of a genomic region, termed C2, residing 3' to miR-17-92 in the intron 3 of C13orf25 led to marked growth inhibition in association with double stranded RNA-dependent protein kinase activation. Finally, this study also revealed that the vast majority of C13orf25 transcripts are detected as Drosha-processed cleavage products on Northern blot analysis and that a novel polyadenylation site is present 3' to the miR-17-92 cluster and 5' to the C2 region. Taken together, the present findings contribute towards better understanding of the oncogenic roles of miR-17-92, which might ultimately lead to the future translation into clinical applications.

CLCP1 interacts with semaphorin 4B and regulates motility of lung cancer cells.

We previously established a highly metastatic subline, LNM35, from the NCI-H460 lung cancer cell line, and demonstrated upregulation of a novel gene, CLCP1 (CUB, LCCL-homology, coagulation factor V/VIII homology domains protein), in LNM35 and lung cancer specimens. In this study, we focused on the potential roles of that gene in cancer metastasis. First, we established stable LNM35 RNAi clones, in which CLCP1 expression was suppressed by RNAi, and found that their motility was significantly reduced, although growth rates were not changed. Next, in vitro selection of a phage display library demonstrated that a phage clone displaying a peptide similar to a sequence within the Sema domain of semaphorin 4B (SEMA4B) interacted with LNM35. Immunoprecipitation experiments confirmed interaction of CLCP1 with SEMA4B, regulation of CLCP1 protein by ubiquitination and proteasome degradation enhanced in the presence of SEMA4B. These results are the first to indicate that CLCP1 plays a role in cell motility, whereas they also showed that at least one of its ligands is SEMA4B and that their interaction mediates proteasome degradation by CLCP1. Although the physiological role of the interaction between CLCP1 and SEMA4B remains to be investigated, this novel gene may become a target of therapy to inhibit metastasis of lung cancers.

Mechanisms of hepatic regeneration following portal vein embolization and partial hepatectomy: a review.

BACKGROUND: Portal vein embolization (PVE) improves outcome following major hepatectomy, and basic studies have presented evidence related to the mechanisms responsible for hepatic regeneration. Hemodynamic changes following PVE are similar to, but slightly different from, those of partial hepatectomy (PH) because arterial flow to the embolized lobe is preserved. However, the process of hepatic regeneration is essentially the same after both PVE and PH. A number of mediators are involved in PVE or PH-induced hepatic regeneration. These include inflammatory cytokines, vasoregulators, growth factors, eicosanoids, and various hormones. These mediators activate a complex network of signal transduction that promotes hepatic regeneration. A variety of conditions have been shown to modulate the function of these mediators and inhibit regeneration. These include biliary obstruction, diabetes, chronic ethanol consumption, malnutrition, gender, aging, and infection. CONCLUSION: Optimizing these factors, where possible, before PVE or PH, is essential to maximize hypertrophy of the liver. A fuller understanding of hepatic physiology and pathophysiology following PVE or PH may lead to greater functional capacity of the remaining liver and extend the indications for hepatectomy in patients who require large liver volume resection.

Intrahepatic cholangiojejunostomy following hepatobiliary resection.

BACKGROUND: Although intrahepatic cholangiojejunostomy is technically difficult, with recent improvements in surgery it should be possible to perform the anastomosis safely. The aim of this study was to evaluate the incidence of anastomotic leak after intrahepatic cholangiojejunostomy and to identify risk factors for such leakage. METHODS: Intrahepatic cholangiojejunostomy was performed in 423 patients undergoing hepatobiliary resection between January 1991 and December 2005. Anastomotic leak was proven radiographically by leakage from the anastomosis of contrast medium introduced via a biliary drainage tube placed during surgery. RESULTS: Anastomotic leak occurred in 27 patients (6.4 per cent), and was not related to the number of bile ducts reconstructed. The leak rate decreased significantly from 9.5 per cent (19 of 199) in the first 10 years to 3.6 per cent (eight of 224) in the last 5 years. Anastomotic leak was often followed by infections such as wound infection, intra-abdominal abscess and bacteraemia. Multivariable analysis identified age and intraoperative blood loss as independent risk factors for anastomotic leak. All leaks were treated by maintaining a prophylactically placed drain near the cholangiojejunostomy; neither repeat laparotomy nor percutaneous transhepatic biliary drainage was required. CONCLUSION: Although demanding, intrahepatic cholangiojejunostomy can be performed successfully with a relatively low failure rate. Routine use of prophylactic drains and anastomotic stenting allows safe management of anastomotic leak with conservative therapy.

Fundamental study of small interfering RNAs for ganglioside GD3 synthase gene as a therapeutic target of lung cancers.

Gangliosides GD3 and GD2 are specifically expressed in neuro-ectoderm-derived tumors, and are considered to play roles in the malignant properties of those cells. We analysed effects of small interfering (si) RNAs against GD3 synthase gene on the expression of ganglioside GD2 and biological phenotypes of human lung cancer cells expressing GD2. An siRNA could suppress the mRNA level of GD3 synthase gene even by single transfection, whereas repeated transfection was required to suppress GD2 expression on the cell surface. Significant reduction in the cell growth and invasion activity was observed in both lung cancer cell lines examined, when repeatedly transfected with the siRNA twice a week. DNA ladder formation was observed after third transfection, indicating the potent induction of apoptosis. Stable transfection of an RNAi expression vector with H1 RNA promoter was also examined. Transfectant cells with the RNAi expression vector showed almost equivalent suppression of GD2 expression and tumor properties in vitro. Furthermore, the stable transfectant cells showed slower cell growth than the control cells in severe combined immunodeficiency mice. These results suggested that siRNAs and/or RNAi expression vectors to generate siRNAs are promising approach to overcome human lung cancers.

Hepatocyte morphology and kinetics after portal vein embolization.

BACKGROUND: Macroscopic volume changes after portal vein embolization (PVE) can be assessed accurately by computed tomography, but histological changes remain poorly understood. The aim of this study was to clarify hepatocyte morphology and kinetics after PVE. METHODS: The resected livers from 25 patients who underwent extended hepatectomy after PVE and five normal livers were examined using hepatocyte paraffin 1 staining for histomorphometric analysis of hepatocytes. Cell kinetics were determined by Ki-67 staining and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay. Kupffer cells were examined by CD68 immunostaining. RESULTS: The number of hepatocytes was similar in the embolized lobe, non-embolized lobe and normal liver, but hepatocyte volume was greater in the non-embolized lobe than in the embolized lobe (P = 0.017). The Ki-67 labelling index was higher in the non-embolized lobe (P < 0.001) whereas the apoptotic index was higher in the embolized lobe (P < 0.001). There were more Kupffer cells per unit area in the embolized lobe (P < 0.001). CONCLUSION: Hepatocyte hypertrophy and replication leads to volume enlargement of the non-embolized hepatic lobe, whereas hepatocyte atrophy and apoptosis causes a decrease in volume of the embolized lobe.

Toll-like receptors 2 and 4 are differentially involved in Fas dependent apoptosis in Peyer's patch and the liver at an early stage after bile duct ligation in mice.

BACKGROUND AND AIMS: Surgical management of extrahepatic cholestasis is frequently complicated by bacterial translocation and severe liver injury. The aim of this study was to clarify the involvement of Toll-like receptors (TLRs) in the pathogenesis of bacterial translocation and liver injury in obstructive cholestasis. METHODS: TLR2 deficient (TLR2(-/-)), MyD88(-/-), Jalpha281(-/-), gld/gld, and lpr/lpr mice, all of which have a C57BL/6 background, and C3H/HeN and TLR4 mutated C3H/HeJ mice were subjected to bile duct ligation (BDL). Faecal IgA and serum alanine aminotransferase levels were determined after BDL. Apoptosis was examined by histological and flow cytometric analyses of cells from Peyer's patches and the liver. RESULTS: The size and number of B cells in Peyer's patches markedly decreased on day 3 after BDL. Increased apoptosis in Peyer's patch B cells was evident on day 1 after BDL in control mice but not in lpr/lpr, MyD88(-/-), or C3H/HeJ mice. On the other hand, TLR2 and Fas ligand expression on intrahepatic NK1.1(+) T cells increased on day 1 after BDL in C57BL/6 mice. Liver injury and apoptosis were evident on day 1 after BDL in control and C3H/HeJ mice but were significantly reduced in TLR2(-/-), Jalpha281(-/-), gld/gld, and lpr/lpr mice. CONCLUSIONS: TLR4 and TLR2 may play important roles in Fas dependent apoptosis in Peyer's patch B cells and hepatocytes, respectively, at an early stage after BDL in mice.

Retrograde portography of the right caudate lobe via the middle hepatic vein.

Hepatobiliary resection with caudate lobectomy has been conducted in the surgical treatment of bile duct carcinoma of the hepatic hilus. However, insufficient attention has been paid to the anatomy of the right portion of the caudate lobe, and techniques to visualize the portal branches of the right caudate lobe (P1r) have not been reported. Contrast medium was injected into the dorso-caudal branches of the middle hepatic vein (MHV) and images were obtained by digital subtraction venography. Retrograde portography of the P1r was achieved in 64 (84%) out of 76 cases. The mean number of visualized branches was 2.1 (137 out of 64) and the P1r coursed beyond the trunk of the MHV in 36 (56%) out of the 64 cases. Contrast medium flowed into the right portal vein from 59 P1r branches in 32 cases and into the left portal vein in 20 cases. No complications were encountered. Retrograde portograms of the P1r may provide valuable information not previously available to surgeons operating on the caudate lobe.

Nucleotide excision repair proteins and their importance for radiation-enhanced transfection.

PURPOSE: Irradiated cells transfect more efficiently than unirradiated cells because of a radiation-induced increase in plasmid integration. However, the molecular mechanism is unclear. Because of recent observations that nucleotide excision repair (NER) proteins can be involved in certain types of recombination in yeast, it was hypothesized that NER proteins might play a role in this radiation-enhanced integration. MATERIALS AND METHODS: Hamster and human cells with inactivating mutations in NER genes were irradiated at doses from 0 to 6 Gy and then immediately transfected with a linearized selectable marker plasmid. Transfection-enhancement ratios (TERs) were calculated as the ratio of the number of drug-resistant colonies in unirradiated cells to the number of transfectants in irradiated cells, corrected for cytotoxicity from radiation. RESULTS: Transfection into unirradiated rodent cells was unaffected by NER mutation status. Transfection into unirradiated human cells, however, was increased by NER mutation. The TERs were 5 and 100 for CHO and primary human fibroblasts, respectively, after exposure of the cells to 6 Gy. Mutations in ERCC1, XPA, XPB, XPC, XPF, XPG and CSB dramatically reduced TER. Mutations in ERCC1, XPC, XPF, XPG and CSB suppressed transfection so that the TER was significantly below 1. CONCLUSIONS: The mechanism of radiation-enhanced plasmid integration was distinct from that of plasmid integration in unirradiated cells, and NER gene products were critical for enhanced integration to occur.

Decrease of deleted in malignant brain tumour-1 (DMBT-1) expression is a crucial late event in intrahepatic cholangiocarcinoma.

AIMS: To investigate the participation of DMBT-1, a candidate tumour suppressor gene, in the development of intrahepatic cholangiocarcinoma via intraductal papillary neoplasm of the liver (IPN-L) arising in hepatolithiasis. DMBT-1 plays a role in mucosal immune defence. METHODS AND RESULTS: The expression of DMBT-1 was examined immunohistochemically in biliary epithelial cells in hepatolithiasis (n = 25), invasive and non-invasive cholangiocarcinoma associated with hepatolithiasis (n = 52), IPN-L with hepatolithiasis (n = 49), cholangiocarcinoma without hepatolithiasis (n = 32), and 10 normal control livers. DMBT-1 was expressed more frequently in the biliary epithelia of hepatolithiasis when compared with normal livers (P < 0.05). DMBT-1 expression was also frequent in IPN-L (57%) and non-invasive cholangiocarcinoma (79%). By contrast, DMBT-1 was decreased in invasive cholangiocarcinoma with and without hepatolithiasis (50% and 30%, respectively) (P < 0.05). The homozygous deletion of the DMBT-1 gene was recognized in four (20%) of 20 cholangiocarcinoma tissues and two (50%) of four cholangiocarcinoma cell lines, corresponding to the reduction of DMBT-1 expression. No deletion was detected in hepatolithiasis tissues. CONCLUSION: DMBT-1 expression is increased in IPN-L and non-invasive cholangiocarcinoma as well as in biliary epithelia in hepatolithiasis. Decreased expression of DMBT-1 and homozygous deletion of the DMBT-1 gene in invasive cholangiocarcinoma suggest that they occur in the late stage of cholangiocarcinogenesis.