Combination gemcitabine plus S-1 versus gemcitabine plus cisplatin for advanced/recurrent biliary tract cancer: the FUGA-BT (JCOG1113) randomized phase III clinical trial.

BACKGROUND: Gemcitabine plus cisplatin (GC) is the standard treatment of advanced biliary tract cancer (BTC); however, it causes nausea, vomiting, and anorexia, and requires hydration. Gemcitabine plus S-1 (GS) reportedly has equal to, or better, efficacy and an acceptable toxicity profile. We aimed to confirm the non-inferiority of GS to GC for patients with advanced/recurrent BTC in terms of overall survival (OS). PATIENTS AND METHODS: We undertook a phase III randomized trial in 33 institutions in Japan. Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable BTC, an Eastern Cooperative Oncology Group Performance Status of 0 - 1, and adequate organ function. The calculated sample size was 350 with a one-sided α of 5%, a power of 80%, and non-inferiority margin hazard ratio (HR) of 1.155. The primary end point was OS, while the secondary end points included progression-free survival (PFS), response rate (RR), adverse events (AEs), and clinically significant AEs defined as grade ≥2 fatigue, anorexia, nausea, vomiting, oral mucositis, or diarrhea. RESULTS: Between May 2013 and March 2016, 354 patients were enrolled. GS was found to be non-inferior to GC [median OS: 13.4 months with GC and 15.1 months with GS, HR, 0.945; 90% confidence interval (CI), 0.78-1.15; P = 0.046 for non-inferiority]. The median PFS was 5.8 months with GC and 6.8 months with GS (HR 0.86; 95% CI 0.70-1.07). The RR was 32.4% with GC and 29.8% with GS. Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm. CONCLUSIONS: GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC. CLINICAL TRIAL NUMBER: This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index.htm), number UMIN000010667.

Updated results from GEST study: a randomized, three-arm phase III study for advanced pancreatic cancer.

PURPOSE: The GEST study showed non-inferiority of S-1 but not superiority of gemcitabine plus S-1 (GS) to gemcitabine alone for overall survival with the data by the cut-off date of 31st July in 2010 for chemo-naïve patients with advanced pancreatic cancer. We considered it important to determine whether S-1 maintains non-inferiority after a long-term follow-up in the GEST study and to obtain a firm positive conclusion. In addition, it may be an interesting challenge to explore the efficacious profile of GS in the long-term follow-up study. Using the data from the follow-up period, background and efficacy in patients from Taiwan and Japan, as well as the rates of tumor shrinkage in locally advanced and metastatic patients (Waterfall plot) were also analyzed. METHODS: The results of the primary analysis were reconfirmed, and subset analysis of overall survival and progression-free survival was performed based on the overall survival data updated by the cut-off date of 31st July in 2011. RESULTS: The median follow-up period was 29.8 months, and 795 deaths occurred (95.6%). The median overall survival was 8.8 months for gemcitabine, 9.7 months for S-1 (hazard ratio [HR], 0.96; 97.5% confidence interval [CI], 0.79-1.17), and 9.9 months for GS (HR 0.91; 97.5% CI 0.75-1.11). In patients with performance status (PS) 0, the median overall survival was 9.8 months for gemcitabine, 10.9 months for S-1, and 10.5 months for GS. In patients with PS 1, the median overall survival was 6.2 months for gemcitabine, 6.3 months for S-1, and 9.6 months for GS. CONCLUSION: Our survey reconfirmed the non-inferiority of S-1 to gemcitabine and showed S-1 can be used as one of the standard treatment options for advanced pancreatic cancer. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00498225.

Sorafenib plus hepatic arterial infusion chemotherapy with cisplatin versus sorafenib for advanced hepatocellular carcinoma: randomized phase II trial.

BACKGROUND: Sorafenib (Sor) is acknowledged as a standard therapy for advanced hepatocellular carcinoma (HCC). This trial was conducted to evaluate the effect of addition of hepatic arterial infusion chemotherapy with cisplatin (SorCDDP) to Sor for the treatment of advanced HCC. PATIENTS AND METHODS: We conducted a multicenter open-labeled randomized phase II trial in chemo-naïve patients with advanced HCC with Child-Pugh scores of 5-7. Eligible patients were randomly assigned 2:1 to receive SorCDDP (sorafenib: 400 mg bid; cisplatin: 65 mg/m2, day 1, every 4-6 weeks) or Sor (400 mg bid). The primary end point was overall survival. RESULTS: A total of 108 patients were randomized (Sor, n = 42; SorCDDP, n = 66). The median survival in the Sor and SorCDDP arms were 8.7 and 10.6 months, respectively [stratified hazard ratio (95% confidence interval), 0.60 (0.38-0.96), P = 0.031]. The median time to progression and the response rate were, respectively, 2.8 months and 7.3% in the Sor arm and 3.1 months and 21.7% in the SorCDDP arm. The adverse events were more frequent in the SorCDDP arm than in the Sor arm, but well-tolerated. CONCLUSION: SorCDDP yielded favorable overall survival when compared with Sor in patients with advanced HCC. CLINICAL TRIAL REGISTRATION: UMIN-CTR (http://www.umin.ac.jp/ctr/index-j.htm), identification number: UMIN000005703.

A randomized phase II study of S-1 plus oral leucovorin versus S-1 monotherapy in patients with gemcitabine-refractory advanced pancreatic cancer.

BACKGROUND: We evaluated the efficacy and toxicity of adding oral leucovorin (LV) to S-1 when compared with S-1 monotherapy in patients with gemcitabine-refractory pancreatic cancer (PC). PATIENTS AND METHODS: Gemcitabine-refractory PC patients were randomly assigned in a 1:1 ratio to receive S-1 at 40, 50, or 60 mg according to body surface area plus LV 25 mg, both given orally twice daily for 1 week, repeated every 2 weeks (SL group), or S-1 monotherapy at the same dose as the SL group for 4 weeks, repeated every 6 weeks (S-1 group). The primary end point was progression-free survival (PFS). RESULTS: Among 142 patients enrolled, 140 were eligible for efficacy assessment (SL: n = 69 and S-1: n = 71). PFS was significantly longer in the SL group than in the S-1 group [median PFS, 3.8 versus 2.7 months; hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.37-0.85; P = 0.003]). The disease control rate was significantly higher in the SL group than in the S-1 group (91% versus 72%; P = 0.004). Overall survival (OS) was similar in both groups (median OS, 6.3 versus 6.1 months; HR, 0.82; 95% CI, 0.54-1.22; P = 0.463). After adjusting for patient background factors in a multivariate analysis, OS tended to be better in the SL group (HR, 0.71; 95% CI, 0.47-1.07; P = 0.099). Both treatments were well tolerated, although gastrointestinal toxicities were slightly more severe in the SL group. CONCLUSION: The addition of LV to S-1 significantly improved PFS in patients with gemcitabine-refractory advanced PC, and a phase III trial has been initiated in a similar setting. CLINICAL TRIALS NUMBER: Japan Pharmaceutical Information Center: JapicCTI-111554.

Randomised phase II trial of S-1 plus oxaliplatin vs S-1 in patients with gemcitabine-refractory pancreatic cancer.

BACKGROUND: This randomised, open-label, multicenter phase II study compared progression-free survival (PFS) of S-1 plus oxaliplatin (SOX) with that of S-1 alone in patients with gemcitabine-refractory pancreatic cancer. METHODS: Patients with confirmed progressive disease following the first-line treatment with a gemcitabine-based regimen were randomised to receive either S-1 (80/100/120 mg day(-1) based on body surface area (BSA), orally, days 1-28, every 6 weeks) or SOX (S-1 80/100/120 mg day(-1) based on BSA, orally, days 1-14, plus oxaliplatin 100 mg m(-2), intravenously, day 1, every 3 weeks). The primary end point was PFS. RESULTS: Between January 2009 and July 2010, 271 patients were randomly allocated to either S-1 (n=135) or SOX (n=136). Median PFS for S-1 and SOX were 2.8 and 3.0 months, respectively (hazard ratio (HR)=0.84; 95% confidence interval (CI), 0.65-1.08; stratified log-rank test P=0.18). Median overall survival (OS) was 6.9 vs 7.4 months (HR=1.03; 95% CI, 0.79-1.34; stratified log-rank test P=0.82). The response rate (RR) was 11.5% vs 20.9% (P=0.04). The major grade 3/4 toxicities (S-1 and SOX) were neutropenia (11.4% and 8.1%), thrombocytopenia (4.5% and 10.3%) and anorexia (12.9% and 14.7%). CONCLUSIONS: Although SOX showed an advantage in RR, it provided no significant improvement in PFS or OS compared with S-1 alone.

Significance of RRM1 and ERCC1 expression in resectable pancreatic adenocarcinoma.

The identification of molecular markers, useful for therapeutic decisions in pancreatic cancer patients, is crucial for advances in disease management. Gemcitabine, although a cornerstone of current therapy, has limited efficacy. RRM1 is a key molecule for gemcitabine efficacy and is also involved in tumor progression. We determined in situ RRM1 and excision repair cross complementation group 1 (ERCC1) protein levels in 68 pancreatic cancer patients. All had R0 resections without preoperative therapy. Protein levels were determined by automated quantitative analysis (AQUA), a fluorescence-based immunohistochemical method. The relationship between protein expressions and clinical outcomes, including response to gemcitabine at the time of disease recurrence, was determined. Patients with high RRM1 showed significantly better overall survival than patients with low expression (P=0.0196). There was a trend toward better overall survival for patient with high ERCC1 (P=0.0552). When both markers were considered together, patients with both high RRM1 and ERCC1 faired the best in terms of overall and disease-free survival (P=0.0066, P=0.0127). In addition, treatment benefit from gemcitabine in patients with disease recurrence was observed only in patients with low RRM1. The combination of RRM1 and ERCC1 expression is prognostic in pancreatic cancer patients after a complete resection. On disease recurrence, only patients with low RRM1 derive benefit from gemcitabine.

Serum intact parathyroid hormone levels predict hospitalisation for heart failure.

OBJECTIVE: To assess whether circulating levels of intact parathyroid hormone (intact PTH) in outpatients predict hospitalisation for heart failure (HF). METHODS: Eighty-eight consecutive outpatients with HF were enrolled in the study. The independent association between intact PTH and hospitalisation for HF was assessed using Cox regression analysis. RESULTS: Mean (SD) serum intact PTH levels significantly increased as New York Heart Association classes increased (I: 40 (21), II: 55 (24), III: 76 (46), IV: 131 (45) pg/ml). The receiver operating characteristic (ROC) curves showed intact PTH levels >or=47 pg/ml to be the optimal cut-off points for hospitalisation for HF, with sensitivity 87%, specificity 71% and area under the ROC curve 0.82 (95% CI 0.72 to 0.91). After adjustment for variables accepted to be predictors for hospitalisation due to HF (age, gender, hypertension, diabetes mellitus, atrial fibrillation, ischaemic heart disease, left ventricular ejection fraction, B-type natriuretic peptide, estimated glomerular filtration rate and cardiac drugs), intact PTH levels >or=47 pg/ml were associated with a hazard ratio of 7.13 for hospitalisation for HF (95% CI 1.79 to 28.4). CONCLUSION: Serum intact PTH levels obtained in outpatients with HF were shown to be an independent predictor of hospitalisation for HF.

The significance of gastrectomy in advanced gastric cancer patients with non-curative factors.

BACKGROUND: The role of gastrectomy in the treatment of advanced gastric cancer patients with non-curative factors remains controversial. We investigated prognostic factors and evaluated the role of gastrectomy in such patients. PATIENTS AND METHODS: Eighty-eight advanced gastric cancer patients with non-curative factors were prospectively studied. The patients were categorized into the following two groups: Group A: 52 patients who underwent gastrectomy and subsequently received chemotherapy, Group B: 36 patients who received chemotherapy alone. RESULTS: The median survival times of group A and B patients were 351 and 182 days, respectively (p=0.008). Multivariate analysis showed that gastrectomy was the only positive independent prognostic factor, with no effect on the results of chemotherapy. There was no significant difference in the duration of hospital stay between patients of the two groups, while significantly longer maintenance of oral intake was observed for group A. CONCLUSION: In advanced gastric cancer patients with non-curative factors, gastrectomy was beneficial for survival with longer maintenance of oral intake.

Biological function of the pld gene product that degrades epsilon-poly-L-lysine in Streptomyces albulus.

Epsilon-poly-L-lysine (epsilon-PL) is one of the few naturally occurring biopolymers and is characterized by a peptide bond between the alpha-carboxyl and epsilon-amino groups. Previously, we purified and characterized the epsilon-PL-degrading enzyme (Pld) from Streptomyces albulus, which is an epsilon-PL producer, and this enzyme was expected to confer self-resistance to the epsilon-PL produced by the organism itself. The gene encoding Pld was cloned based on the N-terminal amino acid sequence determined in this study, and a sequencing analysis revealed eight open reading frames (ORFs), i.e., ORF1 to ORF8 in the flanking region surrounding the pld gene (present in ORF5). To investigate the biological function of Pld, we constructed a knockout mutant in which the pld gene is inactivated. Studies on epsilon-PL susceptibility, epsilon-PL-degrading activity, and epsilon-PL productivity demonstrated that the pld gene does play a partial role in self-resistance and that S. albulus was found to produce other epsilon-PL-degrading enzyme(s) in addition to Pld. To the best of our knowledge, this is the first report on a self-resistance gene for a biopolymer possessing antibacterial activity.

Transthoracic direct current shock facilitates intramyocardial transfection of naked plasmid DNA infused via coronary vessels in canines.

Catheter-mediated, percutaneous, transluminal delivery of naked plasmid DNA (pDNA) into myocardium may offer a valuable strategy to heart diseases. Here, we examined whether clinically available transthoracic direct current (DC) shock improves intracoronary naked DNA transfection into myocardium. Plasmid vector encoding the GL3 luciferase was infused retrogradely into the coronary veins of beagle dogs, whereas another pDNA solution was infused into the left coronary artery. During and after these procedures, the coronary venous sinus was occluded by balloon, and transthoracic DC shock of 200 J was applied immediately after the infusions. Without DC shock, no remarkable increase in luciferase activity was demonstrated in any part of the left ventricular myocardium. In the presence of DC pulsation, significant luciferase expression was detected in the regions that were supplied by left anterior descending coronary artery (LAD), whereas the gene expression in the right coronary artery (RCA) regions was much less drastic. X-gal (5-bromo-4-chloro-3-indolyl-beta-D-galactoside) staining of cardiac cross-sections also revealed regional expression of beta-galactosidase. Immunohistochemical examinations of heart cryosections revealed that cardiomyocytes in LAD regions successfully expressed transgene product. The present system may enable a new strategy for myocardial gene therapy, without any special device or technique other than cardiac catheterization and DC cardioversion that are generally performed in ordinary hospitals.

Treatment of hepatocellular carcinoma with major portal vein thrombosis by combined therapy with subcutaneous interferon-alpha and intra-arterial 5-fluorouracil; role of type 1 interferon receptor expression.

We previously reported the beneficial effects of combination therapy of interferon (IFN)-alpha/5-fluorouracil (FU) for advanced hepatocellular carcinoma (HCC) with tumour thrombi in the major portal branches. This report describes the results of longer follow-up and includes more than double the number of patients relative to the original report, and evaluates the role of IFN-alpha/type 2 interferon receptor (IFNAR2) expression on the response to the combination therapy. The study subjects were 55 patients with advanced HCC and tumour thrombi in the major branches of the portal vein (Vp3 or 4). They were treated with at least two courses of IFN-alpha/5-FU without major complication. In the 55 patients, 24 (43.6%) showed objective response (eight (14.5%) showed complete response, 16 (29.1%) partial response), four (7.3%) showed no response, and 27 (49.1%) showed progressive disease. Immunohistochemically, IFNAR2 expression was detected in nine out of 13 (69.2%) patients. There was significant difference in the time-to-progression survival (P = 0.0002) and the overall survival (P < 0.0001) between IFNAR2-positive and -negative cases. There was a significant correlation between IFNAR2 expression and response to IFN-alpha/5-FU combination therapy in univariate analysis (P = 0.0070). IFN-alpha/5-FU combination therapy is a promising modality for advanced HCC with tumour thrombi in the major portal branches and could significantly depend on IFNAR2 expression.

Identification of differentially expressed genes involved in colorectal carcinogenesis using a cDNA microarray.

To identify candidate genes involved in human colorectal carcinogenesis, we constructed the gene expression profiles of 50 colorectal cancers (CRCs) and 12 normal colorectal epithelia using a cDNA microarray specially constructed for CRC. Hierarchical clustering analysis and principal component analysis could clearly distinguish the gene profiles of cancer tissues from those of normal tissues. Our results confirm there are indeed differences in gene expression between cancer and normal mucosa. Our cDNA microarray identified 22 up-regulated genes and 32 down-regulated genes in CRC. Many of these genes have been previously identified in relation to human carcinogenesis, 68% and 78%, respectively. Subsequent validation of selected genes by serial analysis of gene expression and reverse transcription polymerase chain reaction, demonstrated expression patterns that were almost identical to our microarray analysis. Using a four-fold larger sample relative to that used in our previous study, candidate genes involved in human colorectal carcinogenesis were reproducibly identified. Further studies of comprehensive gene expression using our technique may elucidate the mechanism of CRC tumorigenesis.

PCR-array gene expression profiling of hepatocellular carcinoma.

Many trials using DNA microarrays have been reported for various human malignancies, but an efficient molecular diagnostic system has yet to be established. Here, we adopted a high throughput quantitative PCR-array system based on adaptor-tagged competitive PCR (ATAC-PCR), as a novel technique for gene expression profiling of hepatocellular carcinoma (HCC). This PCR-array contained 3,072 genes derived from three different cDNA libraries, including 298 additional known genes suspected to be involved in hepatocarcinogenesis. Using this PCR-array with 20 pairs of liver tissues (20 HCC, 20 surrounding nontumor liver), we identified a total of 117 genes differing in expression levels in the two liver tissues. Hierarchical clustering analysis and principal component analysis with these genes revealed distinct gene expression patterns in the HBV-positive group and the HCV-positive groups. Among 117 genes, only 7 (GPAA1, TMEM9, FACL4, ADFP, MAWBP, PACE4, FOS) were common to both groups. In conclusion, this PCR-array analysis with an appropriate set of genes is considered useful for gene expression profiling of HCC, and we identified some genes which may play a common key role in hepatocarcinogenesis.

Effect of cysteine desulfhydrase gene disruption on L-cysteine overproduction in Escherichia coli.

In Escherichia coli, the enzyme called cysteine desulfhydrase (CD), which is responsible for L-cysteine degradation, was investigated by native-PAGE and CD activity staining of crude cell extracts. Analyses with gene-disrupted mutants showed that CD activity resulted from two enzymes: tryptophanase (TNase) encoded by tnaA and cystathionine beta-lyase (CBL) encoded by metC. It was also found that TNase synthesis was induced by the presence of L-cysteine. The tnaA and metC mutants transformed with the plasmid containing the gene for feedback-insensitive serine acetyltransferase exhibited higher L-cysteine productivity than the wild-type strain carrying the same plasmid. These results indicated that TNase and CBL did act on L-cysteine degradation in E. coli cells.

An immunohistochemical study of cyclooxygenase (COX)-2 expression in endocrine tumors of the pancreas.

Cyclooxygenase (COX) is a key rate-limiting enzyme in prostaglandin biosynthesis. There are two isoforms of COX, referred to as COX-1 and COX-2. COX-2, an inducible form of COX, is found to be overexpressed in various neoplasms and is believed to play an important role in tumorigenesis and tumor development. In this study, we investigated expression of the COX-2 protein in human endocrine tumors of the pancreas (N=23; 6 insulinomas, one glucagnoma, 2 gastrinomas, and 14 non-functioning tumors) using immunohistochemistry. Strong COX-2 expression was confirmed in normal islet tissue as previously reported. COX-2 immunoreactivity was detected in 65% (15 out of 23) of these tumors with a moderate to strong intensity. In all nine functioning tumors, COX-2 expressions were preserved with the weak or strong intensity. In contrast, COX-2 was present in 6 out of 14 nonfunctioning tumors. The correlation between COX-2 expression and their function was significant (p<0.05). We found that expression of this enzyme was detected in 11 out of 15 benign tumors and in 4 out of 8 malignant tumors, respectively. Our results suggest that COX-2 may play an important role in the endocrine function of islet tumors. Additionally, malignancy was not related to COX-2 expression.

Functional analysis of the propeptides of subtilisin E and aqualysin I as intramolecular chaperones.

Several proteases require propeptides for the correct folding of their own protease domain. We have recently found that the propeptide from a thermostable subtilisin homolog aqualysin I can refold subtilisin BPN' when added in trans. Here, we constructed chimeric genes with subtilisin E and aqualysin I to attempt the in cis folding of subtilisin E by means of the propeptide of aqualysin I. Our results indicate that the propeptide of aqualysin I can to some extent chaperone the intramolecular folding of the denatured subtilisin E. These results suggest that propeptides in the subtilisin family, despite their sequence diversity, have similar functions. Further, some enzymatic properties of some chimeras in which the subtilisin mature domain is partly swapped with that of aqualysin I were shown to be more similar to those of aqualysin I.

[A case of postoperative multiple hepatic metastasis from esophageal cancer successfully treated by surgical resection and hepatic arterial infusion chemotherapy].

A 66-year-old male who underwent radical resection for esophageal cancer (stage IV) was diagnosed with multiple hepatic metastasis 1 year and 3 months after the surgery. He underwent hepatic resection and received systemic chemotherapy (FAP: 5-FU, ADR, CDDP), as the post-operative adjuvant therapy. One year and 3 months later, there was a huge recurrence in the residual liver and hepatic arterial infusion chemotherapy (FAP) was performed. The recurrent lesion disappeared completely after 3 sessions of arterial infusion chemotherapy. The arterial infusion chemotherapy was continued in the outpatient clinic and the recurrent lesion is well controlled. At present, this patient has returned to social life, 2 years and 3 months after the hepatic resection. The utility of hepatic arterial infusion chemotherapy and hepatectomy for postoperative multiple hepatic metastasis from esophageal cancer was shown in the present case.

[A patient with hepatocellular carcinoma and portal vein thrombosis in 1st branch who was treated by transcatheter arterial embolization].

We report a patient with hepatocellular carcinoma (HCC) with portal vein thrombosis in the 1st branch who was treated by transcatheter arterial embolization (TAE) and survived more than 3 years. A 58-year old male was diagnosed as having unresectable massive type HCC in the area of S8 with portal vein thrombosis from the P8 branch to the right portal branch. He was treated by TAE via the anterior branch of right hepatic artery. One week later, localized hepatic infarction in the anterior segment was recognized. Five months later, the portal vein thrombosis had disappeared and become necrotic. After 3 years and 4 months, he died of a relapse of a gastric varix, but with no portal thrombosis and a well controlled intra-hepatic recurrence that was treated by repeated TAE. This case suggests that TAE might be effective for cases of HCC with portal vein thrombosis in the 1st branch, if the liver function and portal flow are suitable.

Differential expression of cyclooxygenase-2 (COX-2) in human bile duct epithelial cells and bile duct neoplasm.

It is well known that chronic inflammatory conditions involving the bile ducts predispose to the development of bile duct carcinoma, although the relationship between chronic inflammation and malignant transformation is unclear. In this study, by combining immunohistochemistry and computer imaging techniques, we quantified and compared the cyclooxygenase-2 (COX-2) protein expression levels of epithelial cells according with their histopathological backgrounds. This technique revealed that the highest levels of COX-2 were expressed in bile duct carcinoma cells, mainly in cytoplasm, and the expression pattern was homogenous and abundant. Moderate levels of COX-2 protein expression were also observed in noncancerous epithelial cells with inflammatory reaction, but the staining intensity was heterogeneous among the positive cells exhibiting inflammation. In contrast, only scattered weak reactivity of COX-2 protein was observed in the noncancerous bile duct epithelial cells without inflammatory reaction. Moreover, bile duct epithelial cells in primary sclerosing cholangitis (PSC) showed very strong expression of COX-2 protein, that was comparable with carcinoma cells. On the other hand, primary biliary cirrhosis (PBC) epithelial cells showed moderate levels of COX-2 expression. In addition, specific COX-2 inhibitors, JTE-522 and NS-398, directly inhibited the growth of 4 bile duct carcinoma and 1 gall bladder carcinoma cell lines that expressed COX-2 protein, in vitro. These data suggest that COX-2 expression might regulate carcinogenesis of bile duct epithelial cells in inflammatory regions and tumor progression in this cancer. The data also suggest that COX-2 selective inhibitors might have therapeutic effects not only on bile duct carcinoma, but other hepatobiliary carcinomas.